v2.2.1

Lookahead tokens are only need if either:
(1) There is more than one rule that could be reduced in a given parser
state, or
(2) There are shift actions for a state and at least one rule that could
be reduced in the same state (to warn about shift/reduce conflicts).

CHANGELOG.md

@@ -1,3 +1,75 @@
+## v2.2.0
+
+### Improvements
+
+- Allow multiple lexer modes to be specified for a lexer pattern (#35)
+- Document p_decode_code_point() API function (#34)
+
+## v2.1.1
+
+### Fixes
+
+- Field aliases for AST node fields could alias incorrect field when multiple rule alternatives present for one rule set (#33)
+
+## v2.1.0
+
+### Improvements
+
+- Report rule name and line number for conflicting AST node field positions errors (#32)
+
+## v2.0.0
+
+### Improvements
+
+- Log conflicting rules on reduce/reduce conflict (#31)
+- Use 1-based row and column values for position values (#30)
+
+### Fixes
+
+- Fix named optional rules (#29)
+
+### Upgrading
+
+- Adjust all uses of p_position_t row and col values to expect 1-based instead
+of 0-based values.
+
+## v1.5.1
+
+### Improvements
+
+- Improve performance (#28)
+
+## v1.5.0
+
+### New Features
+
+- Track start and end text positions for tokens and rules in AST node structures (#27)
+- Add warnings for shift/reduce conflicts to log file (#25)
+- Add -w command line switch to treat warnings as errors and output to stderr (#26)
+- Add rule field aliases (#24)
+
+### Improvements
+
+- Show line numbers of rules on conflict (#23)
+
+## v1.4.0
+
+### New Features
+
+- Allow user to specify AST node name prefix or suffix
+- Allow specifying the start rule name
+- Allow rule terms to be marked as optional
+
+### Improvements
+
+- Give a better error message when a referenced ptype has not been declared
+
+## v1.3.0
+
+### New Features
+
+- Add AST generation (#22)
+
 ## v1.2.0
 
 ### New Features

Gemfile

@@ -1,5 +1,6 @@
 source "https://rubygems.org"
 
+gem "base64"
 gem "rake"
 gem "rspec"
 gem "rdoc"

Gemfile.lock

@@ -1,40 +1,44 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    diff-lcs (1.5.0)
-    docile (1.4.0)
-    psych (5.1.0)
+    base64 (0.2.0)
+    date (3.4.1)
+    diff-lcs (1.6.1)
+    docile (1.4.1)
+    psych (5.2.3)
+      date
       stringio
-    rake (13.0.6)
-    rdoc (6.5.0)
+    rake (13.2.1)
+    rdoc (6.13.1)
       psych (>= 4.0.0)
-    redcarpet (3.6.0)
-    rspec (3.12.0)
-      rspec-core (~> 3.12.0)
-      rspec-expectations (~> 3.12.0)
-      rspec-mocks (~> 3.12.0)
-    rspec-core (3.12.2)
-      rspec-support (~> 3.12.0)
-    rspec-expectations (3.12.3)
+    redcarpet (3.6.1)
+    rspec (3.13.0)
+      rspec-core (~> 3.13.0)
+      rspec-expectations (~> 3.13.0)
+      rspec-mocks (~> 3.13.0)
+    rspec-core (3.13.3)
+      rspec-support (~> 3.13.0)
+    rspec-expectations (3.13.3)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.12.0)
-    rspec-mocks (3.12.6)
+      rspec-support (~> 3.13.0)
+    rspec-mocks (3.13.2)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.12.0)
-    rspec-support (3.12.1)
+      rspec-support (~> 3.13.0)
+    rspec-support (3.13.2)
     simplecov (0.22.0)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
       simplecov_json_formatter (~> 0.1)
-    simplecov-html (0.12.3)
+    simplecov-html (0.13.1)
     simplecov_json_formatter (0.1.4)
-    stringio (3.0.7)
+    stringio (3.1.6)
     syntax (1.2.2)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
+  base64
   rake
   rdoc
   redcarpet

README.md

@@ -6,7 +6,8 @@ Propane is a LALR Parser Generator (LPG) which:
   * generates a built-in lexer to tokenize input
   * supports UTF-8 lexer inputs
   * generates a table-driven shift/reduce parser to parse input in linear time
-  * target C or D language outputs
+  * targets C or D language outputs
+  * optionally supports automatic full AST generation
   * is MIT-licensed
   * is distributable as a standalone Ruby script
 
@@ -17,6 +18,7 @@ can be copied into and versioned in a project's source tree.
 The only requirement to run Propane is that the system has a Ruby interpreter
 installed.
 The latest release can be downloaded from [https://github.com/holtrop/propane/releases](https://github.com/holtrop/propane/releases).
+
 Simply copy the `propane` executable script into the desired location within
 the project to be built (typically the root of the repository) and mark it
 executable.
@@ -29,9 +31,14 @@ Propane is typically invoked from the command-line as `./propane`.
 
     Usage: ./propane [options] <input-file> <output-file>
     Options:
-      --log LOG   Write log file
-      --version   Show program version and exit
-      -h, --help  Show this usage and exit
+      -h, --help  Show this usage and exit.
+      --log LOG   Write log file. This will show all parser states and their
+                  associated shifts and reduces. It can be helpful when
+                  debugging a grammar.
+      --version   Show program version and exit.
+      -w          Treat warnings as errors. This option will treat shift/reduce
+                  conflicts as fatal errors and will print them to stderr in
+                  addition to the log file.
 
 The user must specify the path to a Propane input grammar file and a path to an
 output file.
@@ -55,10 +62,10 @@ import std.math;
 ptype ulong;
 
 # A few basic arithmetic operators.
-token plus /\\+/;
-token times /\\*/;
-token power /\\*\\*/;
-token integer /\\d+/ <<
+token plus /\+/;
+token times /\*/;
+token power /\*\*/;
+token integer /\d+/ <<
   ulong v;
   foreach (c; match)
   {
@@ -67,38 +74,22 @@ token integer /\\d+/ <<
   }
   $$ = v;
 >>
-token lparen /\\(/;
-token rparen /\\)/;
+token lparen /\(/;
+token rparen /\)/;
 # Drop whitespace.
-drop /\\s+/;
+drop /\s+/;
 
-Start -> E1 <<
-  $$ = $1;
->>
-E1 -> E2 <<
-  $$ = $1;
->>
-E1 -> E1 plus E2 <<
-  $$ = $1 + $3;
->>
-E2 -> E3 <<
-  $$ = $1;
->>
-E2 -> E2 times E3 <<
-  $$ = $1 * $3;
->>
-E3 -> E4 <<
-  $$ = $1;
->>
+Start -> E1 << $$ = $1; >>
+E1 -> E2 << $$ = $1; >>
+E1 -> E1 plus E2 << $$ = $1 + $3; >>
+E2 -> E3 << $$ = $1; >>
+E2 -> E2 times E3 << $$ = $1 * $3; >>
+E3 -> E4 << $$ = $1; >>
 E3 -> E3 power E4 <<
   $$ = pow($1, $3);
 >>
-E4 -> integer <<
-  $$ = $1;
->>
-E4 -> lparen E1 rparen <<
-  $$ = $2;
->>
+E4 -> integer << $$ = $1; >>
+E4 -> lparen E1 rparen << $$ = $2; >>
 ```
 
 Grammar files can contain comment lines beginning with `#` which are ignored.

assets/parser.c.erb

@@ -60,6 +60,8 @@ void <%= @grammar.prefix %>context_init(<%= @grammar.prefix %>context_t * contex
     /* Lexer initialization. */
     newcontext.input = input;
     newcontext.input_length = input_length;
+    newcontext.text_position.row = 1u;
+    newcontext.text_position.col = 1u;
     newcontext.mode = <%= @lexer.mode_id("default") %>;
 
     /* Copy to the user's context structure. */
@@ -226,7 +228,10 @@ typedef struct
     /** Number of bytes of input text used to match. */
     size_t length;
 
-    /** Input text position delta. */
+    /** Input text position delta to end of token. */
+    <%= @grammar.prefix %>position_t end_delta_position;
+
+    /** Input text position delta to next code point after token end. */
     <%= @grammar.prefix %>position_t delta_position;
 
     /** Accepting lexer state from the match. */
@@ -320,9 +325,12 @@ static lexer_state_id_t check_lexer_transition(uint32_t current_state, uint32_t
  *
  * @param context
  *   Lexer/parser context structure.
- * @param[out] out_token_info
- *   The lexed token information is stored here if the return value is
- *   P_SUCCESS.
+ * @param[out] out_match_info
+ *   The longest match information is stored here if the return value is
+ *   P_SUCCESS or P_DECODE_ERROR.
+ * @param[out] out_unexpected_input_length
+ *   The unexpected input length is stored here if the return value is
+ *   P_UNEXPECTED_INPUT.
  *
  * @reval P_SUCCESS
  *   A token was successfully lexed.
@@ -355,10 +363,11 @@ static size_t find_longest_match(<%= @grammar.prefix %>context_t * context,
             if (transition_state != INVALID_LEXER_STATE_ID)
             {
                 attempt_match.length += code_point_length;
+                attempt_match.end_delta_position = attempt_match.delta_position;
                 if (code_point == '\n')
                 {
                     attempt_match.delta_position.row++;
-                    attempt_match.delta_position.col = 0u;
+                    attempt_match.delta_position.col = 1u;
                 }
                 else
                 {
@@ -441,7 +450,6 @@ static size_t attempt_lex_token(<%= @grammar.prefix %>context_t * context, <%= @
     <%= @grammar.prefix %>token_info_t token_info = {0};
     token_info.position = context->text_position;
     token_info.token = INVALID_TOKEN_ID;
-    *out_token_info = token_info; // TODO: remove
     lexer_match_info_t match_info;
     size_t unexpected_input_length;
     size_t result = find_longest_match(context, &match_info, &unexpected_input_length);
@@ -488,11 +496,22 @@ static size_t attempt_lex_token(<%= @grammar.prefix %>context_t * context, <%= @
         }
         token_info.token = token_to_accept;
         token_info.length = match_info.length;
+        if (match_info.end_delta_position.row != 0u)
+        {
+            token_info.end_position.row = token_info.position.row + match_info.end_delta_position.row;
+            token_info.end_position.col = match_info.end_delta_position.col;
+        }
+        else
+        {
+            token_info.end_position.row = token_info.position.row;
+            token_info.end_position.col = token_info.position.col + match_info.end_delta_position.col;
+        }
         *out_token_info = token_info;
         return P_SUCCESS;
 
     case P_EOF:
         token_info.token = TOKEN___EOF;
+        token_info.end_position = token_info.position;
         *out_token_info = token_info;
         return P_SUCCESS;
 
@@ -549,6 +568,9 @@ size_t <%= @grammar.prefix %>lex(<%= @grammar.prefix %>context_t * context, <%=
  * Parser
  *************************************************************************/
 
+/** Invalid position value. */
+#define INVALID_POSITION (<%= @grammar.prefix %>position_t){0u, 0u}
+
 /** Reduce ID type. */
 typedef <%= get_type_for(@parser.reduce_table.size) %> reduce_id_t;
 
@@ -608,6 +630,25 @@ typedef struct
      * reduce action.
      */
     parser_state_id_t n_states;
+<% if @grammar.ast %>
+
+    /**
+     * Map of rule components to rule set child fields.
+     */
+    uint16_t const * rule_set_node_field_index_map;
+
+    /**
+     * Number of rule set AST node fields.
+     */
+    uint16_t rule_set_node_field_array_size;
+
+    /**
+     * Whether this rule was a generated optional rule that matched the
+     * optional target. In this case, propagate the matched target node up
+     * instead of making a new node for this rule.
+     */
+    bool propagate_optional_target;
+<% end %>
 } reduce_t;
 
 /** Parser state entry. */
@@ -638,19 +679,55 @@ typedef struct
 
     /** Parser value from this state. */
     <%= @grammar.prefix %>value_t pvalue;
+
+<% if @grammar.ast %>
+    /** AST node. */
+    void * ast_node;
+<% end %>
 } state_value_t;
 
+/** Common AST node structure. */
+typedef struct
+{
+    <%= @grammar.prefix %>position_t position;
+    <%= @grammar.prefix %>position_t end_position;
+    void * fields[];
+} ASTNode;
+
 /** Parser shift table. */
 static const shift_t parser_shift_table[] = {
 <%   @parser.shift_table.each do |shift| %>
-    {<%= shift[:symbol_id] %>u, <%= shift[:state_id] %>u},
+    {<%= shift[:symbol].id %>u, <%= shift[:state_id] %>u},
 <%   end %>
 };
 
+<% if @grammar.ast %>
+<%   @grammar.rules.each do |rule| %>
+<%     unless rule.flat_rule_set_node_field_index_map? %>
+const uint16_t r_<%= rule.name.gsub("$", "_") %><%= rule.id %>_node_field_index_map[<%= rule.rule_set_node_field_index_map.size %>] = {<%= rule.rule_set_node_field_index_map.map {|v| v.to_s}.join(", ") %>};
+<%     end %>
+<%   end %>
+<% end %>
+
 /** Parser reduce table. */
 static const reduce_t parser_reduce_table[] = {
 <%   @parser.reduce_table.each do |reduce| %>
-    {<%= reduce[:token_id] %>u, <%= reduce[:rule_id] %>u, <%= reduce[:rule_set_id] %>u, <%= reduce[:n_states] %>u},
+    {
+        <%= reduce[:token_id] %>u, /* Token: <%= reduce[:token] ? reduce[:token].name : "(any)" %> */
+        <%= reduce[:rule_id] %>u, /* Rule ID */
+        <%= reduce[:rule_set_id] %>u, /* Rule set ID (<%= reduce[:rule].rule_set.name %>) */
+<%     if @grammar.ast %>
+        <%= reduce[:n_states] %>u, /* Number of states */
+<%       if reduce[:rule].flat_rule_set_node_field_index_map? %>
+        NULL, /* No rule set node field index map (flat map) */
+<%       else %>
+        &r_<%= reduce[:rule].name.gsub("$", "_") %><%= reduce[:rule].id %>_node_field_index_map[0], /* Rule set node field index map */
+<%       end %>
+        <%= reduce[:rule].rule_set.ast_fields.size %>, /* Number of AST fields */
+        <%= reduce[:propagate_optional_target] %>}, /* Propagate optional target? */
+<%     else %>
+        <%= reduce[:n_states] %>u},
+<%     end %>
 <%   end %>
 };
 
@@ -754,6 +831,7 @@ static void state_values_stack_free(state_values_stack_t * stack)
      free(stack->entries);
 }
 
+<% unless @grammar.ast %>
 /**
  * Execute user code associated with a parser rule.
  *
@@ -768,18 +846,19 @@ static size_t parser_user_code(<%= @grammar.prefix %>value_t * _pvalue, uint32_t
 {
     switch (rule)
     {
-<% @grammar.rules.each do |rule| %>
-<%   if rule.code %>
+<%   @grammar.rules.each do |rule| %>
+<%     if rule.code %>
     case <%= rule.id %>u: {
 <%= expand_code(rule.code, true, rule, nil) %>
     } break;
+<%     end %>
 <%   end %>
-<% end %>
     default: break;
     }
 
     return P_SUCCESS;
 }
+<% end %>
 
 /**
  * Check if the parser should shift to a new state.
@@ -853,7 +932,11 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
     <%= @grammar.prefix %>token_t token = INVALID_TOKEN_ID;
     state_values_stack_t statevalues;
     size_t reduced_rule_set = INVALID_ID;
+<% if @grammar.ast %>
+    void * reduced_parser_node;
+<% else %>
     <%= @grammar.prefix %>value_t reduced_parser_value;
+<% end %>
     state_values_stack_init(&statevalues);
     state_values_stack_push(&statevalues);
     size_t result;
@@ -880,7 +963,11 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
             if ((shift_state != INVALID_ID) && (token == TOKEN___EOF))
             {
                 /* Successful parse. */
+<% if @grammar.ast %>
+                context->parse_result = (<%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> *)state_values_stack_index(&statevalues, -1)->ast_node;
+<% else %>
                 context->parse_result = state_values_stack_index(&statevalues, -1)->pvalue;
+<% end %>
                 result = P_SUCCESS;
                 break;
             }
@@ -893,15 +980,28 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
             if (reduced_rule_set == INVALID_ID)
             {
                 /* We shifted a token, mark it consumed. */
-                token = INVALID_TOKEN_ID;
+<% if @grammar.ast %>
+                <%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %> * token_ast_node = malloc(sizeof(<%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %>));
+                token_ast_node->position = token_info.position;
+                token_ast_node->end_position = token_info.end_position;
+                token_ast_node->token = token;
+                token_ast_node->pvalue = token_info.pvalue;
+                state_values_stack_index(&statevalues, -1)->ast_node = token_ast_node;
+<% else %>
                 state_values_stack_index(&statevalues, -1)->pvalue = token_info.pvalue;
+<% end %>
+                token = INVALID_TOKEN_ID;
             }
             else
             {
                 /* We shifted a RuleSet. */
+<% if @grammar.ast %>
+                state_values_stack_index(&statevalues, -1)->ast_node = reduced_parser_node;
+<% else %>
                 state_values_stack_index(&statevalues, -1)->pvalue = reduced_parser_value;
                 <%= @grammar.prefix %>value_t new_parse_result = {0};
                 reduced_parser_value = new_parse_result;
+<% end %>
                 reduced_rule_set = INVALID_ID;
             }
             continue;
@@ -911,12 +1011,63 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
         if (reduce_index != INVALID_ID)
         {
             /* We have something to reduce. */
+<% if @grammar.ast %>
+            if (parser_reduce_table[reduce_index].propagate_optional_target)
+            {
+                reduced_parser_node = state_values_stack_index(&statevalues, -1)->ast_node;
+            }
+            else if (parser_reduce_table[reduce_index].n_states > 0)
+            {
+                size_t n_fields = parser_reduce_table[reduce_index].rule_set_node_field_array_size;
+                ASTNode * node = (ASTNode *)malloc(sizeof(ASTNode) + n_fields * sizeof(void *));
+                node->position = INVALID_POSITION;
+                node->end_position = INVALID_POSITION;
+                for (size_t i = 0; i < n_fields; i++)
+                {
+                    node->fields[i] = NULL;
+                }
+                if (parser_reduce_table[reduce_index].rule_set_node_field_index_map == NULL)
+                {
+                    for (size_t i = 0; i < parser_reduce_table[reduce_index].n_states; i++)
+                    {
+                        node->fields[i] = state_values_stack_index(&statevalues, -(int)parser_reduce_table[reduce_index].n_states + (int)i)->ast_node;
+                    }
+                }
+                else
+                {
+                    for (size_t i = 0; i < parser_reduce_table[reduce_index].n_states; i++)
+                    {
+                        node->fields[parser_reduce_table[reduce_index].rule_set_node_field_index_map[i]] = state_values_stack_index(&statevalues, -(int)parser_reduce_table[reduce_index].n_states + (int)i)->ast_node;
+                    }
+                }
+                bool position_found = false;
+                for (size_t i = 0; i < n_fields; i++)
+                {
+                    ASTNode * child = (ASTNode *)node->fields[i];
+                    if ((child != NULL) && <%= @grammar.prefix %>position_valid(child->position))
+                    {
+                        if (!position_found)
+                        {
+                            node->position = child->position;
+                            position_found = true;
+                        }
+                        node->end_position = child->end_position;
+                    }
+                }
+                reduced_parser_node = node;
+            }
+            else
+            {
+                reduced_parser_node = NULL;
+            }
+<% else %>
             <%= @grammar.prefix %>value_t reduced_parser_value2 = {0};
             if (parser_user_code(&reduced_parser_value2, parser_reduce_table[reduce_index].rule, &statevalues, parser_reduce_table[reduce_index].n_states, context) == P_USER_TERMINATED)
             {
                 return P_USER_TERMINATED;
             }
             reduced_parser_value = reduced_parser_value2;
+<% end %>
             reduced_rule_set = parser_reduce_table[reduce_index].rule_set;
             state_values_stack_pop(&statevalues, parser_reduce_table[reduce_index].n_states);
             continue;
@@ -944,9 +1095,17 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context)
  *
  * @return Parse result value.
  */
+<% if @grammar.ast %>
+<%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> * <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context)
+<% else %>
 <%= start_rule_type[1] %> <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context)
+<% end %>
 {
+<% if @grammar.ast %>
+    return context->parse_result;
+<% else %>
     return context->parse_result.v_<%= start_rule_type[0] %>;
+<% end %>
 }
 
 /**

assets/parser.d.erb

@@ -8,6 +8,9 @@
 module <%= @grammar.modulename %>;
 <% end %>
 
+import core.memory;
+import core.stdc.stdlib : malloc;
+
 /**************************************************************************
  * User code blocks
  *************************************************************************/
@@ -49,16 +52,8 @@ public enum : <%= @grammar.prefix %>token_t
 /** Code point type. */
 public alias <%= @grammar.prefix %>code_point_t = uint;
 
-/** Parser values type(s). */
-public union <%= @grammar.prefix %>value_t
-{
-<% @grammar.ptypes.each do |name, typestring| %>
-    <%= typestring %> v_<%= name %>;
-<% end %>
-}
-
 /**
- * A structure to keep track of parser position.
+ * A structure to keep track of input position.
  *
  * This is useful for reporting errors, etc...
  */
@@ -69,14 +64,79 @@ public struct <%= @grammar.prefix %>position_t
 
     /** Input text column (0-based). */
     uint col;
+
+    /** Invalid position value. */
+    enum INVALID = <%= @grammar.prefix %>position_t(0u, 0u);
+
+    /** Return whether the position is valid. */
+    public @property bool valid()
+    {
+        return row != 0u;
+    }
 }
 
+<% if @grammar.ast %>
+/** Parser values type. */
+public alias <%= @grammar.prefix %>value_t = <%= @grammar.ptype %>;
+<% else %>
+/** Parser values type(s). */
+public union <%= @grammar.prefix %>value_t
+{
+<%   @grammar.ptypes.each do |name, typestring| %>
+    <%= typestring %> v_<%= name %>;
+<%   end %>
+}
+<% end %>
+
+<% if @grammar.ast %>
+/** Common AST node structure. */
+private struct ASTNode
+{
+    <%= @grammar.prefix %>position_t position;
+    <%= @grammar.prefix %>position_t end_position;
+    void *[0] fields;
+}
+
+/** AST node types. @{ */
+public struct <%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %>
+{
+    /* ASTNode fields must be present in the same order here. */
+    <%= @grammar.prefix %>position_t position;
+    <%= @grammar.prefix %>position_t end_position;
+    <%= @grammar.prefix %>token_t token;
+    <%= @grammar.prefix %>value_t pvalue;
+}
+
+<%   @parser.rule_sets.each do |name, rule_set| %>
+<%     next if name.start_with?("$") %>
+<%     next if rule_set.optional? %>
+public struct <%= @grammar.ast_prefix %><%= name %><%= @grammar.ast_suffix %>
+{
+    <%= @grammar.prefix %>position_t position;
+    <%= @grammar.prefix %>position_t end_position;
+<%     rule_set.ast_fields.each do |fields| %>
+    union
+    {
+<%       fields.each do |field_name, type| %>
+        <%= type %> * <%= field_name %>;
+<%       end %>
+    }
+<%     end %>
+}
+
+<%   end %>
+/** @} */
+<% end %>
+
 /** Lexed token information. */
 public struct <%= @grammar.prefix %>token_info_t
 {
-    /** Text position where the token was found. */
+    /** Text position of first code point in token. */
     <%= @grammar.prefix %>position_t position;
 
+    /** Text position of last code point in token. */
+    <%= @grammar.prefix %>position_t end_position;
+
     /** Number of input bytes used by the token. */
     size_t length;
 
@@ -112,7 +172,11 @@ public struct <%= @grammar.prefix %>context_t
     /* Parser context data. */
 
     /** Parse result value. */
+<% if @grammar.ast %>
+    <%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> * parse_result;
+<% else %>
     <%= @grammar.prefix %>value_t parse_result;
+<% end %>
 
     /** Unexpected token received. */
     <%= @grammar.prefix %>token_t token;
@@ -172,6 +236,8 @@ public void <%= @grammar.prefix %>context_init(<%= @grammar.prefix %>context_t *
 
     /* Lexer initialization. */
     newcontext.input = input;
+    newcontext.text_position.row = 1u;
+    newcontext.text_position.col = 1u;
     newcontext.mode = <%= @lexer.mode_id("default") %>;
 
     /* Copy to the user's context structure. */
@@ -336,7 +402,10 @@ private struct lexer_match_info_t
     /** Number of bytes of input text used to match. */
     size_t length;
 
-    /** Input text position delta. */
+    /** Input text position delta to end of token. */
+    <%= @grammar.prefix %>position_t end_delta_position;
+
+    /** Input text position delta to next code point after token end. */
     <%= @grammar.prefix %>position_t delta_position;
 
     /** Accepting lexer state from the match. */
@@ -428,9 +497,12 @@ private lexer_state_id_t check_lexer_transition(uint current_state, uint code_po
  *
  * @param context
  *   Lexer/parser context structure.
- * @param[out] out_token_info
- *   The lexed token information is stored here if the return value is
- *   P_SUCCESS.
+ * @param[out] out_match_info
+ *   The longest match information is stored here if the return value is
+ *   P_SUCCESS or P_DECODE_ERROR.
+ * @param[out] out_unexpected_input_length
+ *   The unexpected input length is stored here if the return value is
+ *   P_UNEXPECTED_INPUT.
  *
  * @reval P_SUCCESS
  *   A token was successfully lexed.
@@ -461,10 +533,11 @@ private size_t find_longest_match(<%= @grammar.prefix %>context_t * context,
             if (transition_state != INVALID_LEXER_STATE_ID)
             {
                 attempt_match.length += code_point_length;
+                attempt_match.end_delta_position = attempt_match.delta_position;
                 if (code_point == '\n')
                 {
                     attempt_match.delta_position.row++;
-                    attempt_match.delta_position.col = 0u;
+                    attempt_match.delta_position.col = 1u;
                 }
                 else
                 {
@@ -547,7 +620,6 @@ private size_t attempt_lex_token(<%= @grammar.prefix %>context_t * context, <%=
     <%= @grammar.prefix %>token_info_t token_info;
     token_info.position = context.text_position;
     token_info.token = INVALID_TOKEN_ID;
-    *out_token_info = token_info; // TODO: remove
     lexer_match_info_t match_info;
     size_t unexpected_input_length;
     size_t result = find_longest_match(context, &match_info, &unexpected_input_length);
@@ -594,11 +666,22 @@ private size_t attempt_lex_token(<%= @grammar.prefix %>context_t * context, <%=
         }
         token_info.token = token_to_accept;
         token_info.length = match_info.length;
+        if (match_info.end_delta_position.row != 0u)
+        {
+            token_info.end_position.row = token_info.position.row + match_info.end_delta_position.row;
+            token_info.end_position.col = match_info.end_delta_position.col;
+        }
+        else
+        {
+            token_info.end_position.row = token_info.position.row;
+            token_info.end_position.col = token_info.position.col + match_info.end_delta_position.col;
+        }
         *out_token_info = token_info;
         return P_SUCCESS;
 
     case P_EOF:
         token_info.token = TOKEN___EOF;
+        token_info.end_position = token_info.position;
         *out_token_info = token_info;
         return P_SUCCESS;
 
@@ -714,6 +797,25 @@ private struct reduce_t
      * reduce action.
      */
     parser_state_id_t n_states;
+<% if @grammar.ast %>
+
+    /**
+     * Map of rule components to rule set child fields.
+     */
+    immutable(ushort) * rule_set_node_field_index_map;
+
+    /**
+     * Number of rule set AST node fields.
+     */
+    ushort rule_set_node_field_array_size;
+
+    /**
+     * Whether this rule was a generated optional rule that matched the
+     * optional target. In this case, propagate the matched target node up
+     * instead of making a new node for this rule.
+     */
+    bool propagate_optional_target;
+<% end %>
 }
 
 /** Parser state entry. */
@@ -745,6 +847,11 @@ private struct state_value_t
     /** Parser value from this state. */
     <%= @grammar.prefix %>value_t pvalue;
 
+<% if @grammar.ast %>
+    /** AST node. */
+    void * ast_node;
+<% end %>
+
     this(size_t state_id)
     {
         this.state_id = state_id;
@@ -754,14 +861,37 @@ private struct state_value_t
 /** Parser shift table. */
 private immutable shift_t[] parser_shift_table = [
 <%   @parser.shift_table.each do |shift| %>
-    shift_t(<%= shift[:symbol_id] %>u, <%= shift[:state_id] %>u),
+    shift_t(<%= shift[:symbol].id %>u, <%= shift[:state_id] %>u),
 <%   end %>
 ];
 
+<% if @grammar.ast %>
+<%   @grammar.rules.each do |rule| %>
+<%     unless rule.flat_rule_set_node_field_index_map? %>
+immutable ushort[<%= rule.rule_set_node_field_index_map.size %>] r_<%= rule.name.gsub("$", "_") %><%= rule.id %>_node_field_index_map = [<%= rule.rule_set_node_field_index_map.map {|v| v.to_s}.join(", ") %>];
+<%     end %>
+<%   end %>
+<% end %>
+
 /** Parser reduce table. */
 private immutable reduce_t[] parser_reduce_table = [
 <%   @parser.reduce_table.each do |reduce| %>
-    reduce_t(<%= reduce[:token_id] %>u, <%= reduce[:rule_id] %>u, <%= reduce[:rule_set_id] %>u, <%= reduce[:n_states] %>u),
+    reduce_t(
+        <%= reduce[:token_id] %>u, /* Token: <%= reduce[:token] ? reduce[:token].name : "(any)" %> */
+        <%= reduce[:rule_id] %>u, /* Rule ID */
+        <%= reduce[:rule_set_id] %>u, /* Rule set ID (<%= reduce[:rule].rule_set.name %>) */
+<%     if @grammar.ast %>
+        <%= reduce[:n_states] %>u, /* Number of states */
+<%       if reduce[:rule].flat_rule_set_node_field_index_map? %>
+        null, /* No rule set node field index map (flat map) */
+<%       else %>
+        &r_<%= reduce[:rule].name.gsub("$", "_") %><%= reduce[:rule].id %>_node_field_index_map[0], /* Rule set node field index map */
+<%       end %>
+        <%= reduce[:rule].rule_set.ast_fields.size %>, /* Number of AST fields */
+        <%= reduce[:propagate_optional_target] %>), /* Propagate optional target? */
+<%     else %>
+        <%= reduce[:n_states] %>u), /* Number of states */
+<%     end %>
 <%   end %>
 ];
 
@@ -772,6 +902,7 @@ private immutable parser_state_t[] parser_state_table = [
 <%   end %>
 ];
 
+<% unless @grammar.ast %>
 /**
  * Execute user code associated with a parser rule.
  *
@@ -786,18 +917,19 @@ private size_t parser_user_code(<%= @grammar.prefix %>value_t * _pvalue, uint ru
 {
     switch (rule)
     {
-<% @grammar.rules.each do |rule| %>
-<%   if rule.code %>
+<%   @grammar.rules.each do |rule| %>
+<%     if rule.code %>
     case <%= rule.id %>u: {
 <%= expand_code(rule.code, true, rule, nil) %>
     } break;
+<%     end %>
 <%   end %>
-<% end %>
     default: break;
     }
 
     return P_SUCCESS;
 }
+<% end %>
 
 /**
  * Check if the parser should shift to a new state.
@@ -871,7 +1003,11 @@ public size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * cont
     <%= @grammar.prefix %>token_t token = INVALID_TOKEN_ID;
     state_value_t[] statevalues = new state_value_t[](1);
     size_t reduced_rule_set = INVALID_ID;
+<% if @grammar.ast %>
+    void * reduced_parser_node;
+<% else %>
     <%= @grammar.prefix %>value_t reduced_parser_value;
+<% end %>
     for (;;)
     {
         if (token == INVALID_TOKEN_ID)
@@ -894,7 +1030,11 @@ public size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * cont
             if ((shift_state != INVALID_ID) && (token == TOKEN___EOF))
             {
                 /* Successful parse. */
+<% if @grammar.ast %>
+                context.parse_result = cast(<%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> *)statevalues[$-1].ast_node;
+<% else %>
                 context.parse_result = statevalues[$-1].pvalue;
+<% end %>
                 return P_SUCCESS;
             }
         }
@@ -905,15 +1045,24 @@ public size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * cont
             if (reduced_rule_set == INVALID_ID)
             {
                 /* We shifted a token, mark it consumed. */
-                token = INVALID_TOKEN_ID;
+<% if @grammar.ast %>
+                <%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %> * token_ast_node = new <%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %>(token_info.position, token_info.end_position, token, token_info.pvalue);
+                statevalues[$-1].ast_node = token_ast_node;
+<% else %>
                 statevalues[$-1].pvalue = token_info.pvalue;
+<% end %>
+                token = INVALID_TOKEN_ID;
             }
             else
             {
                 /* We shifted a RuleSet. */
+<% if @grammar.ast %>
+                statevalues[$-1].ast_node = reduced_parser_node;
+<% else %>
                 statevalues[$-1].pvalue = reduced_parser_value;
                 <%= @grammar.prefix %>value_t new_parse_result;
                 reduced_parser_value = new_parse_result;
+<% end %>
                 reduced_rule_set = INVALID_ID;
             }
             continue;
@@ -923,12 +1072,65 @@ public size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * cont
         if (reduce_index != INVALID_ID)
         {
             /* We have something to reduce. */
+<% if @grammar.ast %>
+            if (parser_reduce_table[reduce_index].propagate_optional_target)
+            {
+                reduced_parser_node = statevalues[$ - 1].ast_node;
+            }
+            else if (parser_reduce_table[reduce_index].n_states > 0)
+            {
+                size_t n_fields = parser_reduce_table[reduce_index].rule_set_node_field_array_size;
+                size_t node_size = ASTNode.sizeof + n_fields * (void *).sizeof;
+                ASTNode * node = cast(ASTNode *)malloc(node_size);
+                GC.addRange(node, node_size);
+                node.position = <%= @grammar.prefix %>position_t.INVALID;
+                node.end_position = <%= @grammar.prefix %>position_t.INVALID;
+                foreach (i; 0..n_fields)
+                {
+                    node.fields[i] = null;
+                }
+                if (parser_reduce_table[reduce_index].rule_set_node_field_index_map is null)
+                {
+                    foreach (i; 0..parser_reduce_table[reduce_index].n_states)
+                    {
+                        node.fields[i] = statevalues[$ - parser_reduce_table[reduce_index].n_states + i].ast_node;
+                    }
+                }
+                else
+                {
+                    foreach (i; 0..parser_reduce_table[reduce_index].n_states)
+                    {
+                        node.fields[parser_reduce_table[reduce_index].rule_set_node_field_index_map[i]] = statevalues[$ - parser_reduce_table[reduce_index].n_states + i].ast_node;
+                    }
+                }
+                bool position_found = false;
+                foreach (i; 0..n_fields)
+                {
+                    ASTNode * child = cast(ASTNode *)node.fields[i];
+                    if (child && child.position.valid)
+                    {
+                        if (!position_found)
+                        {
+                            node.position = child.position;
+                            position_found = true;
+                        }
+                        node.end_position = child.end_position;
+                    }
+                }
+                reduced_parser_node = node;
+            }
+            else
+            {
+                reduced_parser_node = null;
+            }
+<% else %>
             <%= @grammar.prefix %>value_t reduced_parser_value2;
             if (parser_user_code(&reduced_parser_value2, parser_reduce_table[reduce_index].rule, statevalues, parser_reduce_table[reduce_index].n_states, context) == P_USER_TERMINATED)
             {
                 return P_USER_TERMINATED;
             }
             reduced_parser_value = reduced_parser_value2;
+<% end %>
             reduced_rule_set = parser_reduce_table[reduce_index].rule_set;
             statevalues.length -= parser_reduce_table[reduce_index].n_states;
             continue;
@@ -953,9 +1155,17 @@ public size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * cont
  *
  * @return Parse result value.
  */
+<% if @grammar.ast %>
+public <%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> * <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context)
+<% else %>
 public <%= start_rule_type[1] %> <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context)
+<% end %>
 {
+<% if @grammar.ast %>
+    return context.parse_result;
+<% else %>
     return context.parse_result.v_<%= start_rule_type[0] %>;
+<% end %>
 }
 
 /**

assets/parser.h.erb

@@ -38,19 +38,8 @@ typedef <%= get_type_for(@grammar.terminate_token_id) %> <%= @grammar.prefix %>t
 /** Code point type. */
 typedef uint32_t <%= @grammar.prefix %>code_point_t;
 
-/** User header code blocks. */
-<%= @grammar.code_blocks.fetch("header", "") %>
-
-/** Parser values type(s). */
-typedef union
-{
-<% @grammar.ptypes.each do |name, typestring| %>
-    <%= typestring %> v_<%= name %>;
-<% end %>
-} <%= @grammar.prefix %>value_t;
-
 /**
- * A structure to keep track of parser position.
+ * A structure to keep track of input position.
  *
  * This is useful for reporting errors, etc...
  */
@@ -63,12 +52,72 @@ typedef struct
     uint32_t col;
 } <%= @grammar.prefix %>position_t;
 
+/** Return whether the position is valid. */
+#define <%= @grammar.prefix %>position_valid(p) ((p).row != 0u)
+
+/** User header code blocks. */
+<%= @grammar.code_blocks.fetch("header", "") %>
+
+<% if @grammar.ast %>
+/** Parser values type. */
+typedef <%= @grammar.ptype %> <%= @grammar.prefix %>value_t;
+<% else %>
+/** Parser values type(s). */
+typedef union
+{
+<%   @grammar.ptypes.each do |name, typestring| %>
+    <%= typestring %> v_<%= name %>;
+<%   end %>
+} <%= @grammar.prefix %>value_t;
+<% end %>
+
+<% if @grammar.ast %>
+/** AST node types. @{ */
+typedef struct <%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %>
+{
+    /* ASTNode fields must be present in the same order here. */
+    <%= @grammar.prefix %>position_t position;
+    <%= @grammar.prefix %>position_t end_position;
+    <%= @grammar.prefix %>token_t token;
+    <%= @grammar.prefix %>value_t pvalue;
+} <%= @grammar.ast_prefix %>Token<%= @grammar.ast_suffix %>;
+
+<%   @parser.rule_sets.each do |name, rule_set| %>
+<%     next if name.start_with?("$") %>
+<%     next if rule_set.optional? %>
+struct <%= name %>;
+<%   end %>
+
+<%   @parser.rule_sets.each do |name, rule_set| %>
+<%     next if name.start_with?("$") %>
+<%     next if rule_set.optional? %>
+typedef struct <%= @grammar.ast_prefix %><%= name %><%= @grammar.ast_suffix %>
+{
+    <%= @grammar.prefix %>position_t position;
+    <%= @grammar.prefix %>position_t end_position;
+<%     rule_set.ast_fields.each do |fields| %>
+    union
+    {
+<%       fields.each do |field_name, type| %>
+        struct <%= type %> * <%= field_name %>;
+<%       end %>
+    };
+<%     end %>
+} <%= @grammar.ast_prefix %><%= name %><%= @grammar.ast_suffix %>;
+
+<%   end %>
+/** @} */
+<% end %>
+
 /** Lexed token information. */
 typedef struct
 {
-    /** Text position where the token was found. */
+    /** Text position of first code point in token. */
     <%= @grammar.prefix %>position_t position;
 
+    /** Text position of last code point in token. */
+    <%= @grammar.prefix %>position_t end_position;
+
     /** Number of input bytes used by the token. */
     size_t length;
 
@@ -107,7 +156,11 @@ typedef struct
     /* Parser context data. */
 
     /** Parse result value. */
+<% if @grammar.ast %>
+    <%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> * parse_result;
+<% else %>
     <%= @grammar.prefix %>value_t parse_result;
+<% end %>
 
     /** Unexpected token received. */
     <%= @grammar.prefix %>token_t token;
@@ -132,7 +185,11 @@ size_t <%= @grammar.prefix %>lex(<%= @grammar.prefix %>context_t * context, <%=
 
 size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context);
 
+<% if @grammar.ast %>
+<%= @grammar.ast_prefix %><%= @grammar.start_rule %><%= @grammar.ast_suffix %> * <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context);
+<% else %>
 <%= start_rule_type[1] %> <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context);
+<% end %>
 
 <%= @grammar.prefix %>position_t <%= @grammar.prefix %>position(<%= @grammar.prefix %>context_t * context);
 

doc/user_guide.md

@@ -14,6 +14,8 @@ Propane is a LALR Parser Generator (LPG) which:
   * supports UTF-8 lexer inputs
   * generates a table-driven shift/reduce parser to parse input in linear time
   * targets C or D language outputs
+  * optionally supports automatic full AST generation
+  * tracks input text start and end positions for all matched tokens/rules
   * is MIT-licensed
   * is distributable as a standalone Ruby script
 
@@ -34,9 +36,14 @@ Propane is typically invoked from the command-line as `./propane`.
 
     Usage: ./propane [options] <input-file> <output-file>
     Options:
-      --log LOG   Write log file
-      --version   Show program version and exit
-      -h, --help  Show this usage and exit
+      -h, --help  Show this usage and exit.
+      --log LOG   Write log file. This will show all parser states and their
+                  associated shifts and reduces. It can be helpful when
+                  debugging a grammar.
+      --version   Show program version and exit.
+      -w          Treat warnings as errors. This option will treat shift/reduce
+                  conflicts as fatal errors and will print them to stderr in
+                  addition to the log file.
 
 The user must specify the path to a Propane input grammar file and a path to an
 output file.
@@ -182,6 +189,143 @@ rule.
 Parser values for the rules or tokens in the rule pattern can be accessed
 positionally with tokens `$1`, `$2`, `$3`, etc...
 
+Parser rule code blocks are not available in AST generation mode.
+In AST generation mode, a full parse tree is automatically constructed in
+memory for user code to traverse after parsing is complete.
+
+##> AST generation mode - the `ast` statement
+
+To activate AST generation mode, place the `ast` statement in your grammar file:
+
+```
+ast;
+```
+
+It is recommended to place this statement early in the grammar.
+
+In AST generation mode various aspects of propane's behavior are changed:
+
+  * Only one `ptype` is allowed.
+  * Parser user code blocks are not supported.
+  * Structure types are generated to represent the parsed tokens and rules as
+  defined in the grammar.
+  * The parse result from `p_result()` points to a `Start` struct containing
+  the entire parse tree for the input. If the user has changed the start rule
+  with the `start` grammar statement, the name of the start struct will be
+  given by the user-specified start rule instead of `Start`.
+
+Example AST generation grammar:
+
+```
+ast;
+
+ptype int;
+
+token a << $$ = 11; >>
+token b << $$ = 22; >>
+token one /1/;
+token two /2/;
+token comma /,/ <<
+  $$ = 42;
+>>
+token lparen /\\(/;
+token rparen /\\)/;
+drop /\\s+/;
+
+Start -> Items;
+
+Items -> Item:item ItemsMore;
+Items -> ;
+
+ItemsMore -> comma Item:item ItemsMore;
+ItemsMore -> ;
+
+Item -> a;
+Item -> b;
+Item -> lparen Item:item rparen;
+Item -> Dual;
+
+Dual -> One Two;
+Dual -> Two One;
+One -> one;
+Two -> two;
+```
+
+The following unit test describes the fields that will be present for an
+example parse:
+
+```
+string input = "a, ((b)), b";
+p_context_t context;
+p_context_init(&context, input);
+assert_eq(P_SUCCESS, p_parse(&context));
+Start * start = p_result(&context);
+assert(start.pItems1 !is null);
+assert(start.pItems !is null);
+Items * items = start.pItems;
+assert(items.item !is null);
+assert(items.item.pToken1 !is null);
+assert_eq(TOKEN_a, items.item.pToken1.token);
+assert_eq(11, items.item.pToken1.pvalue);
+assert(items.pItemsMore !is null);
+ItemsMore * itemsmore = items.pItemsMore;
+assert(itemsmore.item !is null);
+assert(itemsmore.item.item !is null);
+assert(itemsmore.item.item.item !is null);
+assert(itemsmore.item.item.item.pToken1 !is null);
+assert_eq(TOKEN_b, itemsmore.item.item.item.pToken1.token);
+assert_eq(22, itemsmore.item.item.item.pToken1.pvalue);
+assert(itemsmore.pItemsMore !is null);
+itemsmore = itemsmore.pItemsMore;
+assert(itemsmore.item !is null);
+assert(itemsmore.item.pToken1 !is null);
+assert_eq(TOKEN_b, itemsmore.item.pToken1.token);
+assert_eq(22, itemsmore.item.pToken1.pvalue);
+assert(itemsmore.pItemsMore is null);
+```
+
+## `ast_prefix` and `ast_suffix` statements
+
+In AST generation mode, structure types are defined and named based on the
+rules in the grammar.
+Additionally, a structure type called `Token` is generated to hold parsed
+token information.
+
+These structure names can be modified by using the `ast_prefix` or `ast_suffix`
+statements in the grammar file.
+The field names that point to instances of the structures are not affected by
+the `ast_prefix` or `ast_suffix` values.
+
+For example, if the following two lines were added to the example above:
+
+```
+ast_prefix ABC;
+ast_suffix XYZ;
+```
+
+Then the types would be used as such instead:
+
+```
+string input = "a, ((b)), b";
+p_context_t context;
+p_context_init(&context, input);
+assert_eq(P_SUCCESS, p_parse(&context));
+ABCStartXYZ * start = p_result(&context);
+assert(start.pItems1 !is null);
+assert(start.pItems !is null);
+ABCItemsXYZ * items = start.pItems;
+assert(items.pItem !is null);
+assert(items.pItem.pToken1 !is null);
+assert_eq(TOKEN_a, items.pItem.pToken1.token);
+assert_eq(11, items.pItem.pToken1.pvalue);
+assert(items.pItemsMore !is null);
+ABCItemsMoreXYZ * itemsmore = items.pItemsMore;
+assert(itemsmore.pItem !is null);
+assert(itemsmore.pItem.pItem !is null);
+assert(itemsmore.pItem.pItem.pItem !is null);
+assert(itemsmore.pItem.pItem.pItem.pToken1 !is null);
+```
+
 ##> Specifying tokens - the `token` statement
 
 The `token` statement allows defining a lexer token and a pattern to match that
@@ -364,7 +508,7 @@ tokenid str;
   mystringvalue = "";
   $mode(string);
 >>
-string: /[^"]+/ << mystringvalue += match; >>
+string: /[^"]+/ << mystringvalue ~= match; >>
 string: /"/ <<
   $mode(default);
   return $token(str);
@@ -392,6 +536,28 @@ It also returns the `str` token now that the token is complete.
 Note that the token name `str` above could have been `string` instead - the
 namespace for token names is distinct from the namespace for lexer modes.
 
+Multiple modes can be specified for a token or pattern or drop statement.
+For example, if the grammar wanted to only recognize an identifier following
+a `.` token and not other keywords, it could switch to an `identonly` mode
+when matching a `.`
+The `ident` token pattern will be matched in either the `default` or
+`identonly` mode.
+
+```
+ptype char;
+token abc;
+token def;
+default, identonly: token ident /[a-z]+/ <<
+  $$ = match[0];
+  $mode(default);
+  return $token(ident);
+>>
+token dot /\\./ <<
+  $mode(identonly);
+>>
+default, identonly: drop /\\s+/;
+```
+
 ##> Specifying parser value types - the `ptype` statement
 
 The `ptype` statement is used to define parser value type(s).
@@ -442,6 +608,12 @@ In this example:
   * a reduced `Values`'s parser value has a type of `Value[]`.
   * a reduced `KeyValue`'s parser value has a type of `Value[string]`.
 
+When AST generation mode is active, the `ptype` functionality works differently.
+In this mode, only one `ptype` is used by the parser.
+Lexer user code blocks may assign a parse value to the generated `Token` node
+by assigning to `$$` within a lexer code block.
+The type of the parse value `$$` is given by the global `ptype` type.
+
 ##> Specifying a parser rule - the rule statement
 
 Rule statements create parser rules which define the grammar that will be
@@ -452,21 +624,28 @@ Rules with the same name define a rule set for that name and act as
 alternatives that the parser can accept when attempting to match a reference to
 that rule.
 
-The grammar file must define a rule with the name `Start` which will be used as
-the top-level starting rule that the parser attempts to reduce.
+The default start rule name is `Start`.
+This can be changed with the `start` statement.
+The grammar file must define a rule with the name of the start rule name which
+will be used as the top-level starting rule that the parser attempts to reduce.
+
+Rule statements are composed of the name of the rule, a `->` token, the fields
+defining the rule pattern that must be matched, and a terminating semicolon or
+user code block.
 
 Example:
 
 ```
 ptype ulong;
+start Top;
 token word /[a-z]+/ << $$ = match.length; >>
-Start -> word << $$ = $1; >>
+Top -> word << $$ = $1; >>
 ```
 
-In the above example the `Start` rule is defined to match a single `word`
+In the above example the `Top` rule is defined to match a single `word`
 token.
 
-Example:
+Another example:
 
 ```
 Start -> E1 << $$ = $1; >>
@@ -480,16 +659,52 @@ E4 -> integer << $$ = $1; >>
 E4 -> lparen E1 rparen << $$ = $2; >>
 ```
 
-A parser rule has zero or more terms on the right side of its definition.
-Each of these terms is either a token name or a rule name.
+This example uses the default start rule name of `Start`.
 
-In a parser rule code block, parser values for the right side terms are
-accessible as `$1` for the first term's parser value, `$2` for the second
-term's parser value, etc...
+A parser rule has zero or more fields on the right side of its definition.
+Each of these fields is either a token name or a rule name.
+A field can be immediately followed by a `?` character to signify that it is
+optional.
+A field can optionally be followed by a `:` and then a field alias name.
+If present, the field alias name is used to refer to the field value in user
+code blocks, or if AST mode is active, the field alias name is used as the
+field name in the generated AST node structure.
+An optional and named field must use the format `field?:name`.
+Example:
+
+```
+token public;
+token private;
+token int;
+token ident /[a-zA-Z_][a-zA-Z_0-9]*/;
+token semicolon /;/;
+IntegerDeclaration -> Visibility?:visibility int ident:name semicolon;
+Visibility -> public;
+Visibility -> private;
+```
+
+In a parser rule code block, parser values for the right side fields are
+accessible as `$1` for the first field's parser value, `$2` for the second
+field's parser value, etc...
+For the `IntegerDeclaration` rule, the first field value can also be referred to as `${visibility}` and the third field value can also be referred
+to as `${name}`.
 The `$$` symbol accesses the output parser value for this rule.
 The above examples demonstrate how the parser values for the rule components
 can be used to produce the parser value for the accepted rule.
 
+Parser rule code blocks are not allowed and not used when AST generation mode
+is active.
+
+##> Specifying the parser start rule name - the `start` statement
+
+The start rule can be changed from the default of `Start` by using the `start`
+statement.
+Example:
+
+```
+start MyStartRule;
+```
+
 ##> Specifying the parser module name - the `module` statement
 
 The `module` statement can be used to specify the module name for a generated
@@ -569,10 +784,16 @@ Propane generates the following result code constants:
 * `P_EOF`: The lexer reached the end of the input string.
 * `P_USER_TERMINATED`: A parser user code block has requested to terminate the parser.
 
-Result codes are returned by the functions `p_decode_input()`, `p_lex()`, and `p_parse()`.
+Result codes are returned by the functions `p_decode_code_point()`, `p_lex()`, and `p_parse()`.
 
 ##> Types
 
+### `p_code_point_t`
+
+The `p_code_point_t` type is aliased to a 32-bit unsigned integer.
+It is used to store decoded code points from the input text and perform
+lexing based on the grammar's lexer patterns.
+
 ### `p_context_t`
 
 Propane defines a `p_context_t` structure type.
@@ -584,7 +805,101 @@ A pointer to this instance is passed to the generated functions.
 ### `p_position_t`
 
 The `p_position_t` structure contains two fields `row` and `col`.
-These fields contain the 0-based row and column describing a parser position.
+These fields contain the 1-based row and column describing a parser position.
+
+For D targets, the `p_position_t` structure can be checked for validity by
+querying the `valid` property.
+
+For C targets, the `p_position_t` structure can be checked for validity by
+calling `p_position_valid(pos)` where `pos` is a `p_position_t` structure
+instance.
+
+### AST Node Types
+
+If AST generation mode is enabled, a structure type for each rule will be
+generated.
+The name of the structure type is given by the name of the rule.
+Additionally a structure type called `Token` is generated to represent an
+AST node which refers to a raw parser token rather than a composite rule.
+
+#### AST Node Fields
+
+All AST nodes have a `position` field specifying the text position of the
+beginning of the matched token or rule, and an `end_position` field specifying
+the text position of the end of the matched token or rule.
+Each of these fields are instances of the `p_position_t` structure.
+
+A `Token` node will always have a valid `position` and `end_position`.
+A rule node may not have valid positions if the rule allows for an empty match.
+In this case the `position` structure should be checked for validity before
+using it.
+For C targets this can be accomplished with
+`if (p_position_valid(node->position))` and for D targets this can be
+accomplished with `if (node.position.valid)`.
+
+A `Token` node has the following additional fields:
+
+  * `token` which specifies which token was parsed (one of `TOKEN_*`)
+  * `pvalue` which specifies the parser value for the token. If a lexer user
+  code block assigned to `$$`, the assigned value will be stored here.
+
+AST node structures for rules contain generated fields based on the
+right hand side components specified for all rules of a given name.
+
+In this example:
+
+```
+Start -> Items;
+
+Items -> Item ItemsMore;
+Items -> ;
+```
+
+The `Start` structure will have a field called `pItems` and another field of
+the same name but with a positional suffix (`pItems1`) which both point to the
+parsed `Items` node.
+Their value will be null if the parsed `Items` rule was empty.
+
+The `Items` structure will have fields:
+
+  * `pItem` and `pItem1` which point to the parsed `Item` structure.
+  * `pItemsMore` and `pItemsMore2` which point to the parsed `ItemsMore` structure.
+
+If a rule can be empty (for example in the second `Items` rule above), then
+an instance of a pointer to that rule's generated AST node will be null if the
+parser matches the empty rule pattern.
+
+The non-positional AST node field pointer will not be generated if there are
+multiple positions in which an instance of the node it points to could be
+present.
+For example, in the below rules:
+
+```
+Dual -> One Two;
+Dual -> Two One;
+```
+
+The generated `Dual` structure will contain `pOne1`, `pTwo2`, `pTwo1`, and
+`pOne2` fields.
+However, a `pOne` field and `pTwo` field will not be generated since it would
+be ambiguous which one was matched.
+
+If the first rule is matched, then `pOne1` and `pTwo2` will be non-null while
+`pTwo1` and `pOne2` will be null.
+If the second rule is matched instead, then the opposite would be the case.
+
+If a field alias is present in a rule definition, an additional field will be
+generated in the AST node with the field alias name.
+For example:
+
+```
+Exp -> Exp:left plus ExpB:right;
+```
+
+In the generated `Exp` structure, the fields `pExp`, `pExp1`, and `left` will
+all point to the same child node (an instance of the `Exp` structure), and the
+fields `pExpB`, `pExpB3`, and `right` will all point to the same child node
+(an instance of the `ExpB` structure).
 
 ##> Functions
 
@@ -622,6 +937,24 @@ p_context_init(&context, input, input_length);
 size_t result = p_parse(&context);
 ```
 
+### `p_position_valid`
+
+The `p_position_valid()` function is only generated for C targets.
+it is used to determine whether or not a `p_position_t` structure is valid.
+
+Example:
+
+```
+if (p_position_valid(node->position))
+{
+    ....
+}
+```
+
+For D targets, rather than using `p_position_valid()`, the `valid` property
+function of the `p_position_t` structure can be queried
+(e.g. `if (node.position.valid)`).
+
 ### `p_result`
 
 The `p_result()` function can be used to retrieve the final parse value after
@@ -639,6 +972,9 @@ if (p_parse(&context) == P_SUCCESS)
 }
 ```
 
+If AST generation mode is active, then the `p_result()` function returns a
+`Start *` pointing to the `Start` AST structure.
+
 ### `p_position`
 
 The `p_position()` function can be used to retrieve the parser position where
@@ -691,6 +1027,26 @@ if (p_parse(&context) == P_UNEXPECTED_TOKEN)
 }
 ```
 
+### `p_decode_code_point`
+
+The `p_decode_code_point()` function can be used to decode code points from a
+UTF-8 string.
+It does not require a lexer/parser context structure and can be used as a
+standalone UTF-8 decoder or from within a lexer or parser user code block.
+
+D Example:
+
+```
+size_t result;
+p_code_point_t code_point;
+ubyte code_point_length;
+
+result = p_decode_code_point("\xf0\x9f\xa7\xa1", &code_point, &code_point_length);
+assert(result == P_SUCCESS);
+assert(code_point == 0x1F9E1u);
+assert(code_point_length == 4u);
+```
+
 ##> Data
 
 ### `p_token_names`

extra/vim/ftdetect/propane.vim

@@ -0,0 +1 @@
+au BufNewFile,BufRead *.propane set filetype=propane

extra/vim/syntax/propane.vim

@@ -0,0 +1,33 @@
+" Vim syntax file for Propane
+" Language: propane
+" Maintainer: Josh Holtrop
+" URL: https://github.com/holtrop/propane
+
+if exists("b:current_syntax")
+  finish
+endif
+
+if !exists("b:propane_subtype")
+  let b:propane_subtype = "d"
+endif
+
+exe "syn include @propaneTarget syntax/".b:propane_subtype.".vim"
+
+syn region propaneTarget matchgroup=propaneDelimiter start="<<" end=">>$" contains=@propaneTarget keepend
+
+syn match propaneComment "#.*"
+syn match propaneOperator "->"
+syn match propaneFieldAlias ":[a-zA-Z0-9_]\+" contains=propaneFieldOperator
+syn match propaneFieldOperator ":" contained
+syn match propaneOperator "?"
+syn keyword propaneKeyword ast ast_prefix ast_suffix drop module prefix ptype start token tokenid
+
+syn region propaneRegex start="/" end="/" skip="\\/"
+
+hi def link propaneComment Comment
+hi def link propaneKeyword Keyword
+hi def link propaneRegex String
+hi def link propaneOperator Operator
+hi def link propaneFieldOperator Operator
+hi def link propaneDelimiter Delimiter
+hi def link propaneFieldAlias Identifier

lib/propane.rb

@@ -31,10 +31,10 @@ class Propane
 
   class << self
 
-    def run(input_file, output_file, log_file)
+    def run(input_file, output_file, log_file, options)
       begin
         grammar = Grammar.new(File.read(input_file))
-        generator = Generator.new(grammar, output_file, log_file)
+        generator = Generator.new(grammar, output_file, log_file, options)
         generator.generate
       rescue Error => e
         $stderr.puts e.message

lib/propane/cli.rb

@@ -4,15 +4,21 @@ class Propane
     USAGE = <<EOF
 Usage: #{$0} [options] <input-file> <output-file>
 Options:
-  --log LOG   Write log file
-  --version   Show program version and exit
-  -h, --help  Show this usage and exit
+  -h, --help  Show this usage and exit.
+  --log LOG   Write log file. This will show all parser states and their
+              associated shifts and reduces. It can be helpful when
+              debugging a grammar.
+  --version   Show program version and exit.
+  -w          Treat warnings as errors. This option will treat shift/reduce
+              conflicts as fatal errors and will print them to stderr in
+              addition to the log file.
 EOF
 
     class << self
 
       def run(args)
         params = []
+        options = {}
         log_file = nil
         i = 0
         while i < args.size
@@ -24,11 +30,13 @@ EOF
               log_file = args[i]
             end
           when "--version"
-            puts "propane v#{VERSION}"
+            puts "propane version #{VERSION}"
             return 0
           when "-h", "--help"
             puts USAGE
             return 0
+          when "-w"
+            options[:warnings_as_errors] = true
           when /^-/
             $stderr.puts "Error: unknown option #{arg}"
             return 1
@@ -45,7 +53,7 @@ EOF
           $stderr.puts "Error: cannot read #{params[0]}"
           return 2
         end
-        Propane.run(*params, log_file)
+        Propane.run(*params, log_file, options)
       end
 
     end

lib/propane/generator.rb

@@ -2,7 +2,7 @@ class Propane
 
   class Generator
 
-    def initialize(grammar, output_file, log_file)
+    def initialize(grammar, output_file, log_file, options)
       @grammar = grammar
       @output_file = output_file
       if log_file
@@ -16,6 +16,7 @@ class Propane
         else
           "d"
         end
+      @options = options
       process_grammar!
     end
 
@@ -42,8 +43,8 @@ class Propane
       # Assign default pattern mode to patterns without a mode assigned.
       found_default = false
       @grammar.patterns.each do |pattern|
-        if pattern.mode.nil?
-          pattern.mode = "default"
+        if pattern.modes.empty?
+          pattern.modes << "default"
           found_default = true
         end
         pattern.ptypename ||= "default"
@@ -51,6 +52,7 @@ class Propane
       unless found_default
         raise Error.new("No patterns found for default mode")
       end
+      check_ptypes!
       # Add EOF token.
       @grammar.tokens << Token.new("$EOF", nil, nil)
       tokens_by_name = {}
@@ -66,11 +68,14 @@ class Propane
         tokens_by_name[token.name] = token
       end
       # Check for user start rule.
-      unless @grammar.rules.find {|rule| rule.name == "Start"}
-        raise Error.new("Start rule not found")
+      unless @grammar.rules.find {|rule| rule.name == @grammar.start_rule}
+        raise Error.new("Start rule `#{@grammar.start_rule}` not found")
       end
       # Add "real" start rule.
-      @grammar.rules.unshift(Rule.new("$Start", ["Start", "$EOF"], nil, nil, nil))
+      @grammar.rules.unshift(Rule.new("$Start", [@grammar.start_rule, "$EOF"], nil, nil, nil))
+      # Generate and add rules for optional components.
+      generate_optional_component_rules!(tokens_by_name)
+      # Build rule sets.
       rule_sets = {}
       rule_set_id = @grammar.tokens.size
       @grammar.rules.each_with_index do |rule, rule_id|
@@ -119,10 +124,55 @@ class Propane
         end
       end
       determine_possibly_empty_rulesets!(rule_sets)
+      rule_sets.each do |name, rule_set|
+        rule_set.finalize(@grammar)
+      end
       # Generate the lexer.
       @lexer = Lexer.new(@grammar)
       # Generate the parser.
-      @parser = Parser.new(@grammar, rule_sets, @log)
+      @parser = Parser.new(@grammar, rule_sets, @log, @options)
+    end
+
+    # Check that any referenced ptypes have been defined.
+    def check_ptypes!
+      (@grammar.patterns + @grammar.tokens + @grammar.rules).each do |potor|
+        if potor.ptypename
+          unless @grammar.ptypes.include?(potor.ptypename)
+            raise Error.new("Error: Line #{potor.line_number}: ptype #{potor.ptypename} not declared. Declare with `ptype` statement.")
+          end
+        end
+      end
+    end
+
+    # Generate and add rules for any optional components.
+    def generate_optional_component_rules!(tokens_by_name)
+      optional_rules_added = Set.new
+      @grammar.rules.each do |rule|
+        rule.components.each do |component|
+          if component =~ /^(.*)\?$/
+            c = $1
+            unless optional_rules_added.include?(component)
+              # Create two rules for the optional component: one empty and
+              # one just matching the component.
+              # We need to find the ptypename for the optional component in
+              # order to copy it to the generated rules.
+              if tokens_by_name[c]
+                # The optional component is a token.
+                ptypename = tokens_by_name[c].ptypename
+              else
+                # The optional component must be a rule, so find any instance
+                # of that rule that specifies a ptypename.
+                ptypename = @grammar.rules.reduce(nil) do |result, rule|
+                  rule.name == c && rule.ptypename ? rule.ptypename : result
+                end
+              end
+              @grammar.rules << Rule.new(component, [], nil, ptypename, rule.line_number)
+              @grammar.rules << Rule.new(component, [c], "$$ = $1;\n", ptypename, rule.line_number)
+              optional_rules_added << component
+            end
+          end
+        end
+      end
     end
 
     # Determine which grammar rules could expand to empty sequences.
@@ -226,13 +276,35 @@ class Propane
             "statevalues[$-1-n_states+#{index}].pvalue.v_#{rule.components[index - 1].ptypename}"
           end
         end
+        code = code.gsub(/\$\{(\w+)\}/) do |match|
+          aliasname = $1
+          if index = rule.aliases[aliasname]
+            case @language
+            when "c"
+              "state_values_stack_index(statevalues, -(int)n_states + #{index})->pvalue.v_#{rule.components[index].ptypename}"
+            when "d"
+              "statevalues[$-n_states+#{index}].pvalue.v_#{rule.components[index].ptypename}"
+            end
+          else
+            raise Error.new("Field alias '#{aliasname}' not found")
+          end
+        end
       else
         code = code.gsub(/\$\$/) do |match|
-          case @language
-          when "c"
-            "out_token_info->pvalue.v_#{pattern.ptypename}"
-          when "d"
-            "out_token_info.pvalue.v_#{pattern.ptypename}"
+          if @grammar.ast
+            case @language
+            when "c"
+              "out_token_info->pvalue"
+            when "d"
+              "out_token_info.pvalue"
+            end
+          else
+            case @language
+            when "c"
+              "out_token_info->pvalue.v_#{pattern.ptypename}"
+            when "d"
+              "out_token_info.pvalue.v_#{pattern.ptypename}"
+            end
           end
         end
         code = code.gsub(/\$mode\(([a-zA-Z_][a-zA-Z_0-9]*)\)/) do |match|
@@ -258,7 +330,7 @@ class Propane
     #   Start rule parser value type name and type string.
     def start_rule_type
       start_rule = @grammar.rules.find do |rule|
-        rule.name == "Start"
+        rule.name == @grammar.start_rule
       end
       [start_rule.ptypename, @grammar.ptypes[start_rule.ptypename]]
     end

lib/propane/grammar.rb

@@ -5,9 +5,13 @@ class Propane
     # Reserve identifiers beginning with a double-underscore for internal use.
     IDENTIFIER_REGEX = /(?:[a-zA-Z]|_[a-zA-Z0-9])[a-zA-Z_0-9]*/
 
+    attr_reader :ast
+    attr_reader :ast_prefix
+    attr_reader :ast_suffix
     attr_reader :modulename
     attr_reader :patterns
     attr_reader :rules
+    attr_reader :start_rule
     attr_reader :tokens
     attr_reader :code_blocks
     attr_reader :ptypes
@@ -15,15 +19,19 @@ class Propane
 
     def initialize(input)
       @patterns = []
+      @start_rule = "Start"
       @tokens = []
       @rules = []
       @code_blocks = {}
       @line_number = 1
       @next_line_number = @line_number
-      @mode = nil
+      @modeline = nil
       @input = input.gsub("\r\n", "\n")
       @ptypes = {"default" => "void *"}
       @prefix = "p_"
+      @ast = false
+      @ast_prefix = ""
+      @ast_suffix = ""
       parse_grammar!
     end
 
@@ -50,10 +58,14 @@ class Propane
     def parse_statement!
       if parse_white_space!
       elsif parse_comment_line!
-      elsif @mode.nil? && parse_mode_label!
+      elsif @modeline.nil? && parse_mode_label!
+      elsif parse_ast_statement!
+      elsif parse_ast_prefix_statement!
+      elsif parse_ast_suffix_statement!
       elsif parse_module_statement!
       elsif parse_ptype_statement!
       elsif parse_pattern_statement!
+      elsif parse_start_statement!
       elsif parse_token_statement!
       elsif parse_tokenid_statement!
       elsif parse_drop_statement!
@@ -69,8 +81,8 @@ class Propane
     end
 
     def parse_mode_label!
-      if md = consume!(/(#{IDENTIFIER_REGEX})\s*:/)
-        @mode = md[1]
+      if md = consume!(/(#{IDENTIFIER_REGEX}(?:\s*,\s*#{IDENTIFIER_REGEX})*)\s*:/)
+        @modeline = md[1]
       end
     end
 
@@ -82,12 +94,30 @@ class Propane
       consume!(/#.*\n/)
     end
 
+    def parse_ast_statement!
+      if consume!(/ast\s*;/)
+        @ast = true
+      end
+    end
+
+    def parse_ast_prefix_statement!
+      if md = consume!(/ast_prefix\s+(\w+)\s*;/)
+        @ast_prefix = md[1]
+      end
+    end
+
+    def parse_ast_suffix_statement!
+      if md = consume!(/ast_suffix\s+(\w+)\s*;/)
+        @ast_suffix = md[1]
+      end
+    end
+
     def parse_module_statement!
       if consume!(/module\s+/)
         md = consume!(/([\w.]+)\s*/, "expected module name")
         @modulename = md[1]
         consume!(/;/, "expected `;'")
-        @mode = nil
+        @modeline = nil
         true
       end
     end
@@ -96,6 +126,9 @@ class Propane
       if consume!(/ptype\s+/)
         name = "default"
         if md = consume!(/(#{IDENTIFIER_REGEX})\s*=\s*/)
+          if @ast
+            raise Error.new("Multiple ptypes are unsupported in AST mode")
+          end
           name = md[1]
         end
         md = consume!(/([^;]+);/, "expected parser result type expression")
@@ -108,18 +141,21 @@ class Propane
         md = consume!(/(#{IDENTIFIER_REGEX})\s*/, "expected token name")
         name = md[1]
         if md = consume!(/\((#{IDENTIFIER_REGEX})\)\s*/)
+          if @ast
+            raise Error.new("Multiple ptypes are unsupported in AST mode")
+          end
           ptypename = md[1]
         end
         pattern = parse_pattern! || name
         consume!(/\s+/)
         unless code = parse_code_block!
-          consume!(/;/, "expected pattern or `;' or code block")
+          consume!(/;/, "expected `;' or code block")
         end
         token = Token.new(name, ptypename, @line_number)
         @tokens << token
-        pattern = Pattern.new(pattern: pattern, token: token, line_number: @line_number, code: code, mode: @mode, ptypename: ptypename)
+        pattern = Pattern.new(pattern: pattern, token: token, line_number: @line_number, code: code, modes: get_modes_from_modeline, ptypename: ptypename)
         @patterns << pattern
-        @mode = nil
+        @modeline = nil
         true
       end
     end
@@ -129,12 +165,15 @@ class Propane
         md = consume!(/(#{IDENTIFIER_REGEX})\s*/, "expected token name")
         name = md[1]
         if md = consume!(/\((#{IDENTIFIER_REGEX})\)\s*/)
+          if @ast
+            raise Error.new("Multiple ptypes are unsupported in AST mode")
+          end
           ptypename = md[1]
         end
         consume!(/;/, "expected `;'");
         token = Token.new(name, ptypename, @line_number)
         @tokens << token
-        @mode = nil
+        @modeline = nil
         true
       end
     end
@@ -147,8 +186,8 @@ class Propane
         end
         consume!(/\s+/)
         consume!(/;/, "expected `;'")
-        @patterns << Pattern.new(pattern: pattern, line_number: @line_number, mode: @mode)
-        @mode = nil
+        @patterns << Pattern.new(pattern: pattern, line_number: @line_number, modes: get_modes_from_modeline)
+        @modeline = nil
         true
       end
     end
@@ -156,13 +195,20 @@ class Propane
     def parse_rule_statement!
       if md = consume!(/(#{IDENTIFIER_REGEX})\s*(?:\((#{IDENTIFIER_REGEX})\))?\s*->\s*/)
         rule_name, ptypename = *md[1, 2]
-        md = consume!(/((?:#{IDENTIFIER_REGEX}\s*)*)\s*/, "expected rule component list")
+        if @ast && ptypename
+          raise Error.new("Multiple ptypes are unsupported in AST mode")
+        end
+        md = consume!(/((?:#{IDENTIFIER_REGEX}\??(?::#{IDENTIFIER_REGEX})?\s*)*)\s*/, "expected rule component list")
         components = md[1].strip.split(/\s+/)
-        unless code = parse_code_block!
-          consume!(/;/, "expected pattern or `;' or code block")
+        if @ast
+          consume!(/;/, "expected `;'")
+        else
+          unless code = parse_code_block!
+            consume!(/;/, "expected `;' or code block")
+          end
         end
         @rules << Rule.new(rule_name, components, code, ptypename, @line_number)
-        @mode = nil
+        @modeline = nil
         true
       end
     end
@@ -171,17 +217,26 @@ class Propane
       if pattern = parse_pattern!
         consume!(/\s+/)
         if md = consume!(/\((#{IDENTIFIER_REGEX})\)\s*/)
+          if @ast
+            raise Error.new("Multiple ptypes are unsupported in AST mode")
+          end
           ptypename = md[1]
         end
         unless code = parse_code_block!
           raise Error.new("Line #{@line_number}: expected code block to follow pattern")
         end
-        @patterns << Pattern.new(pattern: pattern, line_number: @line_number, code: code, mode: @mode, ptypename: ptypename)
-        @mode = nil
+        @patterns << Pattern.new(pattern: pattern, line_number: @line_number, code: code, modes: get_modes_from_modeline, ptypename: ptypename)
+        @modeline = nil
         true
       end
     end
 
+    def parse_start_statement!
+      if md = consume!(/start\s+(\w+)\s*;/)
+        @start_rule = md[1]
+      end
+    end
+
     def parse_code_block_statement!
       if md = consume!(/<<([a-z]*)(.*?)>>\n/m)
         name, code = md[1..2]
@@ -192,7 +247,7 @@ class Propane
         else
           @code_blocks[name] = code
         end
-        @mode = nil
+        @modeline = nil
         true
       end
     end
@@ -260,6 +315,14 @@ class Propane
       end
     end
 
+    def get_modes_from_modeline
+      if @modeline
+        Set[*@modeline.split(",").map(&:strip)]
+      else
+        Set.new
+      end
+    end
+
   end
 
 end

lib/propane/lexer.rb

@@ -26,8 +26,14 @@ class Propane
     private
 
     def build_tables!
-      @modes = @grammar.patterns.group_by do |pattern|
-        pattern.mode
+      modenames = @grammar.patterns.reduce(Set.new) do |result, pattern|
+        result + pattern.modes
+      end
+      @modes = modenames.reduce({}) do |result, modename|
+        result[modename] = @grammar.patterns.select do |pattern|
+          pattern.modes.include?(modename)
+        end
+        result
       end.transform_values do |patterns|
         {dfa: DFA.new(patterns)}
       end

lib/propane/parser.rb

@@ -7,12 +7,15 @@ class Propane
     attr_reader :reduce_table
     attr_reader :rule_sets
 
-    def initialize(grammar, rule_sets, log)
+    def initialize(grammar, rule_sets, log, options)
       @grammar = grammar
       @rule_sets = rule_sets
       @log = log
       @item_sets = []
       @item_sets_set = {}
+      @warnings = Set.new
+      @errors = Set.new
+      @options = options
       start_item = Item.new(grammar.rules.first, 0)
       eval_item_sets = Set[ItemSet.new([start_item])]
 
@@ -23,10 +26,10 @@ class Propane
           item_set.id = @item_sets.size
           @item_sets << item_set
           @item_sets_set[item_set] = item_set
-          item_set.following_symbols.each do |following_symbol|
-            unless following_symbol.name == "$EOF"
-              following_set = item_set.build_following_item_set(following_symbol)
-              eval_item_sets << following_set
+          item_set.next_symbols.each do |next_symbol|
+            unless next_symbol.name == "$EOF"
+              next_item_set = item_set.build_next_item_set(next_symbol)
+              eval_item_sets << next_item_set
             end
           end
         end
@@ -37,8 +40,21 @@ class Propane
       end
 
       build_reduce_actions!
-      write_log!
       build_tables!
+      write_log!
+      errormessage = ""
+      if @errors.size > 0
+        errormessage += @errors.join("\n")
+      end
+      if @warnings.size > 0 && @options[:warnings_as_errors]
+        if errormessage != ""
+          errormessage += "\n"
+        end
+        errormessage += "Fatal errors (-w):\n" + @warnings.join("\n")
+      end
+      if errormessage != ""
+        raise Error.new(errormessage)
+      end
     end
 
     private
@@ -48,27 +64,37 @@ class Propane
       @shift_table = []
       @reduce_table = []
       @item_sets.each do |item_set|
-        shift_entries = item_set.following_symbols.map do |following_symbol|
+        shift_entries = item_set.next_symbols.map do |next_symbol|
           state_id =
-            if following_symbol.name == "$EOF"
+            if next_symbol.name == "$EOF"
               0
             else
-              item_set.following_item_set[following_symbol].id
+              item_set.next_item_set[next_symbol].id
             end
           {
-            symbol_id: following_symbol.id,
+            symbol: next_symbol,
             state_id: state_id,
           }
         end
+        unless item_set.reduce_rules.empty?
+          shift_entries.each do |shift_entry|
+            token = shift_entry[:symbol]
+            if get_lookahead_reduce_actions_for_item_set(item_set).include?(token)
+              rule = item_set.reduce_actions[token]
+              @warnings << "Shift/Reduce conflict (state #{item_set.id}) between token #{token.name} and rule #{rule.name} (defined on line #{rule.line_number})"
+            end
+          end
+        end
         reduce_entries =
-          case ra = item_set.reduce_actions
-          when Rule
-            [{token_id: @grammar.invalid_token_id, rule_id: ra.id,
-              rule_set_id: ra.rule_set.id, n_states: ra.components.size}]
-          when Hash
-            ra.map do |token, rule|
-              {token_id: token.id, rule_id: rule.id,
-               rule_set_id: rule.rule_set.id, n_states: rule.components.size}
+          if rule = item_set.reduce_rule
+            [{token_id: @grammar.invalid_token_id, rule_id: rule.id, rule: rule,
+              rule_set_id: rule.rule_set.id, n_states: rule.components.size,
+              propagate_optional_target: rule.optional? && rule.components.size == 1}]
+          elsif reduce_actions = item_set.reduce_actions
+            reduce_actions.map do |token, rule|
+              {token: token, token_id: token.id, rule_id: rule.id, rule: rule,
+               rule_set_id: rule.rule_set.id, n_states: rule.components.size,
+               propagate_optional_target: rule.optional? && rule.components.size == 1}
             end
           else
             []
@@ -85,11 +111,11 @@ class Propane
     end
 
     def process_item_set(item_set)
-      item_set.following_symbols.each do |following_symbol|
-        unless following_symbol.name == "$EOF"
-          following_set = @item_sets_set[item_set.build_following_item_set(following_symbol)]
-          item_set.following_item_set[following_symbol] = following_set
-          following_set.in_sets << item_set
+      item_set.next_symbols.each do |next_symbol|
+        unless next_symbol.name == "$EOF"
+          next_item_set = @item_sets_set[item_set.build_next_item_set(next_symbol)]
+          item_set.next_item_set[next_symbol] = next_item_set
+          next_item_set.in_sets << item_set
         end
       end
     end
@@ -99,7 +125,7 @@ class Propane
     # @return [void]
     def build_reduce_actions!
       @item_sets.each do |item_set|
-        item_set.reduce_actions = build_reduce_actions_for_item_set(item_set)
+        build_reduce_actions_for_item_set(item_set)
       end
     end
 
@@ -108,38 +134,55 @@ class Propane
     # @param item_set [ItemSet]
     #   ItemSet (parser state)
     #
-    # @return [nil, Rule, Hash]
-    #   If no reduce actions are possible for the given item set, nil.
-    #   If only one reduce action is possible for the given item set, the Rule
-    #   to reduce.
-    #   Otherwise, a mapping of lookahead Tokens to the Rules to reduce.
+    # @return [void]
     def build_reduce_actions_for_item_set(item_set)
       # To build the reduce actions, we start by looking at any
       # "complete" items, i.e., items where the parse position is at the
       # end of a rule. These are the only rules that are candidates for
       # reduction in the current ItemSet.
-      reduce_rules = Set.new(item_set.items.select(&:complete?).map(&:rule))
+      item_set.reduce_rules = Set.new(item_set.items.select(&:complete?).map(&:rule))
 
-      # If there are no rules to reduce for this ItemSet, we're done here.
-      return nil if reduce_rules.size == 0
+      if item_set.reduce_rules.size == 1
+        item_set.reduce_rule = item_set.reduce_rules.first
+      end
 
-      # If there is exactly one rule to reduce for this ItemSet, then do not
-      # figure out the lookaheads; just reduce it.
-      return reduce_rules.first if reduce_rules.size == 1
+      if item_set.reduce_rules.size > 1
+        # Force item_set.reduce_actions to be built to store the lookahead
+        # tokens for the possible reduce rules if there is more than one.
+        get_lookahead_reduce_actions_for_item_set(item_set)
+      end
+    end
 
-      # Otherwise, we have more than one possible rule to reduce.
+    # Get the reduce actions for a single item set (parser state).
+    #
+    # @param item_set [ItemSet]
+    #   ItemSet (parser state)
+    #
+    # @return [Hash]
+    #   Mapping of lookahead Tokens to the Rules to reduce.
+    def get_lookahead_reduce_actions_for_item_set(item_set)
+      item_set.reduce_actions ||= build_lookahead_reduce_actions_for_item_set(item_set)
+    end
 
+    # Build the reduce actions for a single item set (parser state).
+    #
+    # @param item_set [ItemSet]
+    #   ItemSet (parser state)
+    #
+    # @return [Hash]
+    #   Mapping of lookahead Tokens to the Rules to reduce.
+    def build_lookahead_reduce_actions_for_item_set(item_set)
       # We will be looking for all possible tokens that can follow instances of
       # these rules. Rather than looking through the entire grammar for the
       # possible following tokens, we will only look in the item sets leading
       # up to this one. This restriction gives us a more precise lookahead set,
       # and allows us to parse LALR grammars.
       item_sets = Set[item_set] + item_set.leading_item_sets
-      reduce_rules.reduce({}) do |reduce_actions, reduce_rule|
+      item_set.reduce_rules.reduce({}) do |reduce_actions, reduce_rule|
         lookahead_tokens_for_rule = build_lookahead_tokens_to_reduce(reduce_rule, item_sets)
         lookahead_tokens_for_rule.each do |lookahead_token|
           if existing_reduce_rule = reduce_actions[lookahead_token]
-            raise Error.new("Error: reduce/reduce conflict between rule #{existing_reduce_rule.id} (#{existing_reduce_rule.name}) and rule #{reduce_rule.id} (#{reduce_rule.name})")
+            @errors << "Error: reduce/reduce conflict (state #{item_set.id}) between rule #{existing_reduce_rule.name}##{existing_reduce_rule.id} (defined on line #{existing_reduce_rule.line_number}) and rule #{reduce_rule.name}##{reduce_rule.id} (defined on line #{reduce_rule.line_number}) for lookahead token #{lookahead_token}"
           end
           reduce_actions[lookahead_token] = reduce_rule
         end
@@ -181,9 +224,9 @@ class Propane
         # tokens to form the lookahead token set.
         item_sets.each do |item_set|
           item_set.items.each do |item|
-            if item.following_symbol == rule_set
+            if item.next_symbol == rule_set
               (1..).each do |offset|
-                case symbol = item.following_symbol(offset)
+                case symbol = item.next_symbol(offset)
                 when nil
                   rule_set = item.rule.rule_set
                   unless checked_rule_sets.include?(rule_set)
@@ -240,20 +283,26 @@ class Propane
         @log.puts
         @log.puts "  Incoming states: #{incoming_ids.join(", ")}"
         @log.puts "  Outgoing states:"
-        item_set.following_item_set.each do |following_symbol, following_item_set|
-          @log.puts "    #{following_symbol.name} => #{following_item_set.id}"
+        item_set.next_item_set.each do |next_symbol, next_item_set|
+          @log.puts "    #{next_symbol.name} => #{next_item_set.id}"
         end
         @log.puts
         @log.puts "  Reduce actions:"
-        case item_set.reduce_actions
-        when Rule
-          @log.puts "    * => rule #{item_set.reduce_actions.id}, rule set #{@rule_sets[item_set.reduce_actions.name].id} (#{item_set.reduce_actions.name})"
-        when Hash
+        if item_set.reduce_rule
+          @log.puts "    * => rule #{item_set.reduce_rule.id}, rule set #{@rule_sets[item_set.reduce_rule.name].id} (#{item_set.reduce_rule.name})"
+        elsif item_set.reduce_actions
           item_set.reduce_actions.each do |token, rule|
             @log.puts "    lookahead #{token.name} => #{rule.name} (#{rule.id}), rule set ##{rule.rule_set.id}"
           end
         end
       end
+      if @warnings.size > 0
+        @log.puts
+        @log.puts "Warnings:"
+        @warnings.each do |warning|
+          @log.puts "  #{warning}"
+        end
+      end
     end
 
   end

lib/propane/parser/item.rb

@@ -56,7 +56,7 @@ class Propane
 
       # Return the set of Items obtained by "closing" the current item.
       #
-      # If the following symbol for the current item is another Rule name, then
+      # If the next symbol for the current item is another Rule name, then
       # this method will return all Items for that Rule with a position of 0.
       # Otherwise, an empty Array is returned.
       #
@@ -81,17 +81,17 @@ class Propane
         @position == @rule.components.size
       end
 
-      # Get the following symbol for the Item.
+      # Get the next symbol for the Item.
       #
-      # That is, the symbol which follows the parse position marker in the
+      # That is, the symbol which is after the parse position marker in the
       # current Item.
       #
       # @param offset [Integer]
       #   Offset from current parse position to examine.
       #
       # @return [Token, RuleSet, nil]
-      #   Following symbol for the Item.
-      def following_symbol(offset = 0)
+      #   Next symbol for the Item.
+      def next_symbol(offset = 0)
         @rule.components[@position + offset]
       end
 
@@ -108,25 +108,25 @@ class Propane
         end
       end
 
-      # Get whether this Item is followed by the provided symbol.
+      # Get whether this Item's next symbol is the given symbol.
       #
       # @param symbol [Token, RuleSet]
       #   Symbol to query.
       #
       # @return [Boolean]
-      #   Whether this Item is followed by the provided symbol.
-      def followed_by?(symbol)
-        following_symbol == symbol
+      #   Whether this Item's next symbol is the given symbol.
+      def next_symbol?(symbol)
+        next_symbol == symbol
       end
 
-      # Get the following item for this Item.
+      # Get the next item for this Item.
       #
       # That is, the Item formed by moving the parse position marker one place
       # forward from its position in this Item.
       #
       # @return [Item]
-      #   The following item for this Item.
-      def following_item
+      #   The next item for this Item.
+      def next_item
         Item.new(@rule, @position + 1)
       end
 

lib/propane/parser/item_set.rb

@@ -2,7 +2,7 @@ class Propane
   class Parser
 
     # Represent a parser "item set", which is a set of possible items that the
-    # parser could currently be parsing.
+    # parser could currently be parsing. This is equivalent to a parser state.
     class ItemSet
 
       # @return [Set<Item>]
@@ -14,15 +14,24 @@ class Propane
       attr_accessor :id
 
       # @return [Hash]
-      #   Maps a following symbol to its ItemSet.
-      attr_reader :following_item_set
+      #   Maps a next symbol to its ItemSet.
+      attr_reader :next_item_set
 
       # @return [Set<ItemSet>]
       #   ItemSets leading to this item set.
       attr_reader :in_sets
 
-      # @return [nil, Rule, Hash]
-      #   Reduce actions, mapping lookahead tokens to rules.
+      # @return [nil, Rule]
+      #   Rule to reduce if there is only one possibility.
+      attr_accessor :reduce_rule
+
+      # @return [Set<Rule>]
+      #   Set of rules that could be reduced in this parser state.
+      attr_accessor :reduce_rules
+
+      # @return [nil, Hash]
+      #   Reduce actions, mapping lookahead tokens to rules, if there is
+      #   more than one rule that could be reduced.
       attr_accessor :reduce_actions
 
       # Build an ItemSet.
@@ -31,28 +40,28 @@ class Propane
       #   Items in this ItemSet.
       def initialize(items)
         @items = Set.new(items)
-        @following_item_set = {}
+        @next_item_set = {}
         @in_sets = Set.new
         close!
       end
 
-      # Get the set of following symbols for all Items in this ItemSet.
+      # Get the set of next symbols for all Items in this ItemSet.
       #
       # @return [Set<Token, RuleSet>]
-      #   Set of following symbols for all Items in this ItemSet.
-      def following_symbols
-        Set.new(@items.map(&:following_symbol).compact)
+      #   Set of next symbols for all Items in this ItemSet.
+      def next_symbols
+        @_next_symbols ||= Set.new(@items.map(&:next_symbol).compact)
       end
 
-      # Build a following ItemSet for the given following symbol.
+      # Build a next ItemSet for the given next symbol.
       #
       # @param symbol [Token, RuleSet]
-      #   Following symbol to build the following ItemSet for.
+      #   Next symbol to build the next ItemSet for.
       #
       # @return [ItemSet]
-      #   Following ItemSet for the given following symbol.
-      def build_following_item_set(symbol)
-        ItemSet.new(items_followed_by(symbol).map(&:following_item))
+      #   Next ItemSet for the given next symbol.
+      def build_next_item_set(symbol)
+        ItemSet.new(items_with_next(symbol).map(&:next_item))
       end
 
       # Hash function.
@@ -90,21 +99,24 @@ class Propane
       # @return [Set<ItemSet>]
       #   Set of all ItemSets that lead up to this ItemSet.
       def leading_item_sets
-        result = Set.new
-        eval_sets = Set[self]
-        evaled = Set.new
-        while eval_sets.size > 0
-          eval_set = eval_sets.first
-          eval_sets.delete(eval_set)
-          evaled << eval_set
-          eval_set.in_sets.each do |in_set|
-            result << in_set
-            unless evaled.include?(in_set)
-              eval_sets << in_set
+        @_leading_item_sets ||=
+          begin
+            result = Set.new
+            eval_sets = Set[self]
+            evaled = Set.new
+            while eval_sets.size > 0
+              eval_set = eval_sets.first
+              eval_sets.delete(eval_set)
+              evaled << eval_set
+              eval_set.in_sets.each do |in_set|
+                result << in_set
+                unless evaled.include?(in_set)
+                  eval_sets << in_set
+                end
+              end
             end
+            result
           end
-        end
-        result
       end
 
       # Represent the ItemSet as a String.
@@ -137,16 +149,16 @@ class Propane
         end
       end
 
-      # Get the Items followed by the given following symbol.
+      # Get the Items with the given next symbol.
       #
       # @param symbol [Token, RuleSet]
-      #   Following symbol.
+      #   Next symbol.
       #
       # @return [Array<Item>]
-      #   Items followed by the given following symbol.
-      def items_followed_by(symbol)
+      #   Items with the given next symbol.
+      def items_with_next(symbol)
         @items.select do |item|
-          item.followed_by?(symbol)
+          item.next_symbol?(symbol)
         end
       end
 

lib/propane/pattern.rb

@@ -26,9 +26,9 @@ class Propane
     #   Regex NFA for matching the pattern.
     attr_reader :nfa
 
-    # @return [String, nil]
-    #   Lexer mode for this pattern.
-    attr_accessor :mode
+    # @return [Set]
+    #   Lexer modes for this pattern.
+    attr_accessor :modes
 
     # @return [String, nil]
     #   Parser value type name.
@@ -46,14 +46,14 @@ class Propane
     #   Token to be returned by this pattern.
     # @option options [Integer, nil] :line_number
     #   Line number where the token was defined in the input grammar.
-    # @option options [String, nil] :mode
-    #   Lexer mode for this pattern.
+    # @option options [String, nil] :modes
+    #   Lexer modes for this pattern.
     def initialize(options)
       @code = options[:code]
       @pattern = options[:pattern]
       @token = options[:token]
       @line_number = options[:line_number]
-      @mode = options[:mode]
+      @modes = options[:modes]
       @ptypename = options[:ptypename]
       regex = Regex.new(@pattern)
       regex.nfa.end_state.accepts = self

lib/propane/rule.rb

@@ -6,6 +6,10 @@ class Propane
     #   Rule components.
     attr_reader :components
 
+    # @return [Hash]
+    #   Field aliases.
+    attr_reader :aliases
+
     # @return [String]
     #   User code associated with the rule.
     attr_reader :code
@@ -30,6 +34,11 @@ class Propane
     #   The RuleSet that this Rule is a part of.
     attr_accessor :rule_set
 
+    # @return [Array<Integer>]
+    #   Map this rule's components to their positions in the parent RuleSet's
+    #   node field pointer array. This is used for AST construction.
+    attr_accessor :rule_set_node_field_index_map
+
     # Construct a Rule.
     #
     # @param name [String]
@@ -44,7 +53,20 @@ class Propane
     #   Line number where the rule was defined in the input grammar.
     def initialize(name, components, code, ptypename, line_number)
       @name = name
-      @components = components
+      @aliases = {}
+      @components = components.each_with_index.map do |component, i|
+        if component =~ /(\S+):(\S+)/
+          c, aliasname = $1, $2
+          if @aliases[aliasname]
+            raise Error.new("Error: duplicate field alias `#{aliasname}` for rule #{name} defined on line #{line_number}")
+          end
+          @aliases[aliasname] = i
+          c
+        else
+          component
+        end
+      end
+      @rule_set_node_field_index_map = components.map {0}
       @code = code
       @ptypename = ptypename
       @line_number = line_number
@@ -60,6 +82,14 @@ class Propane
       @components.empty?
     end
 
+    # Return whether this is an optional Rule.
+    #
+    # @return [Boolean]
+    #   Whether this is an optional Rule.
+    def optional?
+      @name.end_with?("?")
+    end
+
     # Represent the Rule as a String.
     #
     # @return [String]
@@ -68,6 +98,17 @@ class Propane
       "#{@name} -> #{@components.map(&:name).join(" ")}"
     end
 
+    # Check whether the rule set node field index map is just a 1:1 mapping.
+    #
+    # @return [Boolean]
+    #   Boolean indicating whether the rule set node field index map is just a
+    #   1:1 mapping.
+    def flat_rule_set_node_field_index_map?
+      @rule_set_node_field_index_map.each_with_index.all? do |v, i|
+        v == i
+      end
+    end
+
   end
 
 end

lib/propane/rule_set.rb

@@ -1,7 +1,12 @@
 class Propane
 
+  # A RuleSet collects all grammar rules of the same name.
   class RuleSet
 
+    # @return [Array<Hash>]
+    #   AST fields.
+    attr_reader :ast_fields
+
     # @return [Integer]
     #   ID of the RuleSet.
     attr_reader :id
@@ -51,6 +56,24 @@ class Propane
       @could_be_empty
     end
 
+    # Return whether this is an optional RuleSet.
+    #
+    # @return [Boolean]
+    #   Whether this is an optional RuleSet.
+    def optional?
+      @name.end_with?("?")
+    end
+
+    # For optional rule sets, return the underlying component that is optional.
+    def option_target
+      @rules.each do |rule|
+        if rule.components.size > 0
+          return rule.components[0]
+        end
+      end
+      raise "Optional rule target not found"
+    end
+
     # Build the start token set for the RuleSet.
     #
     # @return [Set<Token>]
@@ -75,6 +98,72 @@ class Propane
       @_start_token_set
     end
 
+    # Finalize a RuleSet after adding all Rules to it.
+    def finalize(grammar)
+      if grammar.ast
+        build_ast_fields(grammar)
+      end
+    end
+
+    private
+
+    # Build the set of AST fields for this RuleSet.
+    #
+    # This is an Array of Hashes. Each entry in the Array corresponds to a
+    # field location in the AST node. The entry is a Hash. It could have one or
+    # two keys. It will always have the field name with a positional suffix as
+    # a key. It may also have the field name without the positional suffix if
+    # that field only exists in one position across all Rules in the RuleSet.
+    #
+    # @return [void]
+    def build_ast_fields(grammar)
+      field_ast_node_indexes = {}
+      field_indexes_across_all_rules = {}
+      # Stores the index into @ast_fields by field alias name.
+      field_aliases = {}
+      @ast_fields = []
+      @rules.each do |rule|
+        rule.components.each_with_index do |component, i|
+          if component.is_a?(RuleSet) && component.optional?
+            component = component.option_target
+          end
+          if component.is_a?(Token)
+            node_name = "Token"
+          else
+            node_name = component.name
+          end
+          struct_name = "#{grammar.ast_prefix}#{node_name}#{grammar.ast_suffix}"
+          field_name = "p#{node_name}#{i + 1}"
+          unless field_ast_node_indexes[field_name]
+            field_ast_node_indexes[field_name] = @ast_fields.size
+            @ast_fields << {field_name => struct_name}
+          end
+          rule.aliases.each do |alias_name, index|
+            if index == i
+              alias_ast_fields_index = field_ast_node_indexes[field_name]
+              if field_aliases[alias_name] && field_aliases[alias_name] != alias_ast_fields_index
+                raise Error.new("Error: conflicting AST node field positions for alias `#{alias_name}` in rule #{rule.name} defined on line #{rule.line_number}")
+              end
+              field_aliases[alias_name] = alias_ast_fields_index
+              @ast_fields[alias_ast_fields_index][alias_name] = @ast_fields[alias_ast_fields_index].first[1]
+            end
+          end
+          field_indexes_across_all_rules[node_name] ||= Set.new
+          field_indexes_across_all_rules[node_name] << field_ast_node_indexes[field_name]
+          rule.rule_set_node_field_index_map[i] = field_ast_node_indexes[field_name]
+        end
+      end
+      field_indexes_across_all_rules.each do |node_name, indexes_across_all_rules|
+        if indexes_across_all_rules.size == 1
+          # If this field was only seen in one position across all rules,
+          # then add an alias to the positional field name that does not
+          # include the position.
+          @ast_fields[indexes_across_all_rules.first]["p#{node_name}"] =
+            "#{grammar.ast_prefix}#{node_name}#{grammar.ast_suffix}"
+        end
+      end
+    end
+
   end
 
 end

lib/propane/version.rb

@@ -1,3 +1,3 @@
 class Propane
-  VERSION = "1.2.0"
+  VERSION = "2.2.1"
 end

spec/ast_node_memory_remains.c.propane

@@ -0,0 +1,151 @@
+ast;
+ast_prefix P;
+
+<<header
+#include <stdio.h>
+#include <stdint.h>
+
+typedef union
+{
+    uint64_t i64;
+    const uint8_t * s;
+    double dou;
+} TokenVal;
+>>
+
+ptype TokenVal;
+
+# Keywords.
+token byte;
+token def;
+token int;
+token long;
+token module;
+token return;
+token short;
+token size_t;
+token ssize_t;
+token ubyte;
+token uint;
+token ulong;
+token ushort;
+
+# Symbols.
+token arrow /->/;
+token comma /,/;
+token lbrace /\{/;
+token lparen /\(/;
+token rbrace /\}/;
+token rparen /\)/;
+token semicolon /;/;
+
+# Integer literals.
+token hex_int_l /0[xX][0-9a-fA-F][0-9a-fA-F_]*/ <<
+  $$.i64 = 64u;
+>>
+
+# Identifier.
+token ident /\$?[a-zA-Z_][a-zA-Z_0-9]*\??/ <<
+  $$.s = match;
+  $mode(default);
+  return $token(ident);
+>>
+
+# Comments.
+drop /#.*/;
+
+# Whitespace.
+drop /[ \r\n]*/;
+
+start Module;
+
+# Assignment operators - right associative
+Expression -> Expression_Or:exp0;
+
+# Logical OR operator - left associative
+Expression_Or -> Expression_And:exp0;
+
+# Logical AND operator - left associative
+Expression_And -> Expression_Comp:exp0;
+
+# Equality operators - left associative
+Expression_Comp -> Expression_Relational:exp0;
+
+# Relational operators - left associative
+Expression_Relational -> Expression_REMatch:exp0;
+
+# Regular expression - left associative
+Expression_REMatch -> Expression_BinOr:exp0;
+
+# Binary OR operator - left associative
+Expression_BinOr -> Expression_Xor:exp0;
+
+# Binary XOR operator - left associative
+Expression_Xor -> Expression_BinAnd:exp0;
+
+# Binary AND operator - left associative
+Expression_BinAnd -> Expression_BitShift:exp0;
+
+# Bit shift operators - left associative
+Expression_BitShift -> Expression_Plus:exp0;
+
+# Add/subtract operators - left associative
+Expression_Plus -> Expression_Mul:exp0;
+
+# Multiplication/divide/modulus operators - left associative
+Expression_Mul -> Expression_Range:exp0;
+
+# Range construction operators - left associative
+Expression_Range -> Expression_UnaryPrefix:exp0;
+
+# Unary prefix operators
+Expression_UnaryPrefix -> Expression_Dot:exp0;
+
+# Postfix operators
+Expression_Dot -> Expression_Ident:exp0;
+Expression_Dot -> Expression_Dot:exp1 lparen rparen;
+
+# Literals, identifiers, and parenthesized expressions
+Expression_Ident -> Literal;
+Expression_Ident -> ident;
+
+FunctionDefinition -> def ident:name lparen FunctionParameterList?:parameters rparen FunctionReturnType?:returntype lbrace Statements rbrace;
+
+FunctionParameterList -> ident:name Type:type FunctionParameterListMore?:more;
+FunctionParameterListMore -> comma ident:name Type:type FunctionParameterListMore?:more;
+
+FunctionReturnType -> arrow Type;
+
+Literal -> LiteralInteger;
+LiteralInteger -> hex_int_l;
+
+Module -> ModuleStatement? ModuleItems;
+
+ModuleItem -> FunctionDefinition;
+
+ModuleItems -> ;
+ModuleItems -> ModuleItems ModuleItem;
+
+ModulePath -> ident;
+
+ModuleStatement -> module ModulePath semicolon;
+
+ReturnStatement -> return Expression?:exp0 semicolon;
+
+Statements -> ;
+Statements -> Statements Statement;
+Statement -> Expression semicolon;
+Statement -> ReturnStatement;
+
+Type -> TypeBase;
+
+TypeBase -> byte;
+TypeBase -> ubyte;
+TypeBase -> short;
+TypeBase -> ushort;
+TypeBase -> int;
+TypeBase -> uint;
+TypeBase -> long;
+TypeBase -> ulong;
+TypeBase -> size_t;
+TypeBase -> ssize_t;

spec/ast_node_memory_remains.d.propane

@@ -0,0 +1,177 @@
+ast;
+ast_prefix P;
+
+<<
+import std.bigint;
+
+private string stringvalue;
+
+union TokenVal
+{
+    BigInt bi;
+    string s;
+    double dou;
+}
+>>
+
+ptype TokenVal;
+
+# Keywords.
+token byte;
+token def;
+token int;
+token long;
+token module;
+token return;
+token short;
+token size_t;
+token ssize_t;
+token ubyte;
+token uint;
+token ulong;
+token ushort;
+
+# Symbols.
+token arrow /->/;
+token comma /,/;
+token lbrace /\{/;
+token lparen /\(/;
+token rbrace /\}/;
+token rparen /\)/;
+token semicolon /;/;
+
+# Integer literals.
+token hex_int_l /0[xX][0-9a-fA-F][0-9a-fA-F_]*/ <<
+  $$.bi = BigInt(match[0..3]);
+  foreach (c; match[3..$])
+  {
+    if (('0' <= c) && (c <= '9'))
+    {
+      $$.bi *= 0x10;
+      $$.bi += (c - '0');
+    }
+    if (('a' <= c) && (c <= 'f'))
+    {
+      $$.bi *= 0x10;
+      $$.bi += (c - 'a' + 10);
+    }
+    if (('A' <= c) && (c <= 'F'))
+    {
+      $$.bi *= 0x10;
+      $$.bi += (c - 'A' + 10);
+    }
+  }
+>>
+
+# Identifier.
+token ident /\$?[a-zA-Z_][a-zA-Z_0-9]*\??/ <<
+  if (match[0] == '$')
+  {
+    $$.s = match[1..$];
+  }
+  else
+  {
+    $$.s = match;
+  }
+  $mode(default);
+  return $token(ident);
+>>
+
+# Comments.
+drop /#.*/;
+
+# Whitespace.
+drop /[ \r\n]*/;
+
+start Module;
+
+# Assignment operators - right associative
+Expression -> Expression_Or:exp0;
+
+# Logical OR operator - left associative
+Expression_Or -> Expression_And:exp0;
+
+# Logical AND operator - left associative
+Expression_And -> Expression_Comp:exp0;
+
+# Equality operators - left associative
+Expression_Comp -> Expression_Relational:exp0;
+
+# Relational operators - left associative
+Expression_Relational -> Expression_REMatch:exp0;
+
+# Regular expression - left associative
+Expression_REMatch -> Expression_BinOr:exp0;
+
+# Binary OR operator - left associative
+Expression_BinOr -> Expression_Xor:exp0;
+
+# Binary XOR operator - left associative
+Expression_Xor -> Expression_BinAnd:exp0;
+
+# Binary AND operator - left associative
+Expression_BinAnd -> Expression_BitShift:exp0;
+
+# Bit shift operators - left associative
+Expression_BitShift -> Expression_Plus:exp0;
+
+# Add/subtract operators - left associative
+Expression_Plus -> Expression_Mul:exp0;
+
+# Multiplication/divide/modulus operators - left associative
+Expression_Mul -> Expression_Range:exp0;
+
+# Range construction operators - left associative
+Expression_Range -> Expression_UnaryPrefix:exp0;
+
+# Unary prefix operators
+Expression_UnaryPrefix -> Expression_Dot:exp0;
+
+# Postfix operators
+Expression_Dot -> Expression_Ident:exp0;
+Expression_Dot -> Expression_Dot:exp1 lparen rparen;
+
+# Literals, identifiers, and parenthesized expressions
+Expression_Ident -> Literal;
+Expression_Ident -> ident;
+
+FunctionDefinition -> def ident:name lparen FunctionParameterList?:parameters rparen FunctionReturnType?:returntype lbrace Statements rbrace;
+
+FunctionParameterList -> ident:name Type:type FunctionParameterListMore?:more;
+FunctionParameterListMore -> comma ident:name Type:type FunctionParameterListMore?:more;
+
+FunctionReturnType -> arrow Type;
+
+Literal -> LiteralInteger;
+LiteralInteger -> hex_int_l;
+
+Module -> ModuleStatement? ModuleItems;
+
+ModuleItem -> FunctionDefinition;
+
+ModuleItems -> ;
+ModuleItems -> ModuleItems ModuleItem;
+
+ModulePath -> ident;
+
+ModuleStatement -> module ModulePath semicolon;
+
+ReturnStatement -> return Expression?:exp0 semicolon;
+
+Statements -> ;
+Statements -> Statements Statement;
+Statement -> Expression semicolon;
+Statement -> ReturnStatement;
+
+Type -> TypeBase;
+
+TypeBase -> byte;
+TypeBase -> ubyte;
+TypeBase -> short;
+TypeBase -> ushort;
+TypeBase -> int;
+TypeBase -> uint;
+TypeBase -> long;
+TypeBase -> ulong;
+TypeBase -> size_t;
+TypeBase -> ssize_t;

spec/propane/grammar_spec.rb

@@ -151,30 +151,30 @@ EOF
 
       o = grammar.patterns.find {|pattern| pattern.token == o}
       expect(o).to_not be_nil
-      expect(o.mode).to be_nil
+      expect(o.modes).to be_empty
 
       o = grammar.tokens.find {|token| token.name == "b"}
       expect(o).to_not be_nil
 
       o = grammar.patterns.find {|pattern| pattern.token == o}
       expect(o).to_not be_nil
-      expect(o.mode).to eq "m1"
+      expect(o.modes).to eq Set["m1"]
 
       o = grammar.patterns.find {|pattern| pattern.pattern == "foo"}
       expect(o).to_not be_nil
-      expect(o.mode).to be_nil
+      expect(o.modes).to be_empty
 
       o = grammar.patterns.find {|pattern| pattern.pattern == "bar"}
       expect(o).to_not be_nil
-      expect(o.mode).to eq "m2"
+      expect(o.modes).to eq Set["m2"]
 
       o = grammar.patterns.find {|pattern| pattern.pattern == "q"}
       expect(o).to_not be_nil
-      expect(o.mode).to be_nil
+      expect(o.modes).to be_empty
 
       o = grammar.patterns.find {|pattern| pattern.pattern == "r"}
       expect(o).to_not be_nil
-      expect(o.mode).to eq "m3"
+      expect(o.modes).to eq Set["m3"]
     end
 
     it "allows assigning ptypes to tokens and rules" do

spec/propane_spec.rb

@@ -13,7 +13,7 @@ describe Propane do
     File.write("spec/run/testparser#{options[:name]}.propane", grammar)
   end
 
-  def build_parser(options = {})
+  def run_propane(options = {})
     @statics[:build_test_id] ||= 0
     @statics[:build_test_id] += 1
     if ENV["dist_specs"]
@@ -49,7 +49,12 @@ ENV["TERM"] = nil
 EOF
       end
     end
-    command += %W[spec/run/testparser#{options[:name]}.propane spec/run/testparser#{options[:name]}.#{options[:language]} --log spec/run/testparser#{options[:name]}.log]
+    if options[:args]
+      command += options[:args]
+    else
+      command += %W[spec/run/testparser#{options[:name]}.propane spec/run/testparser#{options[:name]}.#{options[:language]} --log spec/run/testparser#{options[:name]}.log]
+    end
+    command += (options[:extra_args] || [])
     if (options[:capture])
       stdout, stderr, status = Open3.capture3(*command)
       Results.new(stdout, stderr, status)
@@ -69,12 +74,12 @@ EOF
     when "c"
       result = system(*%w[gcc -Wall -o spec/run/testparser -Ispec -Ispec/run], *parsers, *test_files, "spec/testutils.c", "-lm")
     when "d"
-      result = system(*%w[ldc2 --unittest -of spec/run/testparser -Ispec], *parsers, *test_files, "spec/testutils.d")
+      result = system(*%w[ldc2 -g --unittest -of spec/run/testparser -Ispec], *parsers, *test_files, "spec/testutils.d")
     end
     expect(result).to be_truthy
   end
 
-  def run
+  def run_test
     stdout, stderr, status = Open3.capture3("spec/run/testparser")
     File.binwrite("spec/run/.stderr", stderr)
     File.binwrite("spec/run/.stdout", stdout)
@@ -112,6 +117,138 @@ EOF
     FileUtils.mkdir_p("spec/run")
   end
 
+  it "reports its version" do
+    results = run_propane(args: %w[--version], capture: true)
+    expect(results.stdout).to match /propane version \d+\.\d+/
+    expect(results.stderr).to eq ""
+    expect(results.status).to eq 0
+  end
+
+  it "shows help usage" do
+    results = run_propane(args: %w[-h], capture: true)
+    expect(results.stdout).to match /Usage/i
+    expect(results.stderr).to eq ""
+    expect(results.status).to eq 0
+  end
+
+  it "errors with unknown option" do
+    results = run_propane(args: %w[-i], capture: true)
+    expect(results.stderr).to match /Error: unknown option -i/
+    expect(results.status).to_not eq 0
+  end
+
+  it "errors when input and output files are not specified" do
+    results = run_propane(args: [], capture: true)
+    expect(results.stderr).to match /Error: specify input and output files/
+    expect(results.status).to_not eq 0
+  end
+
+  it "errors when input file is not readable" do
+    results = run_propane(args: %w[nope.txt out.d], capture: true)
+    expect(results.stderr).to match /Error: cannot read nope.txt/
+    expect(results.status).to_not eq 0
+  end
+
+  it "raises an error when a pattern referenced ptype has not been defined" do
+    write_grammar <<EOF
+ptype yes = int;
+/foo/ (yes) <<
+>>
+/bar/ (no) <<
+>>
+EOF
+    results = run_propane(capture: true)
+    expect(results.stderr).to match /Error: Line 4: ptype no not declared\. Declare with `ptype` statement\./
+    expect(results.status).to_not eq 0
+  end
+
+  it "raises an error when a token referenced ptype has not been defined" do
+    write_grammar <<EOF
+ptype yes = int;
+token foo (yes);
+token bar (no);
+EOF
+    results = run_propane(capture: true)
+    expect(results.stderr).to match /Error: Line 3: ptype no not declared\. Declare with `ptype` statement\./
+    expect(results.status).to_not eq 0
+  end
+
+  it "raises an error when a rule referenced ptype has not been defined" do
+    write_grammar <<EOF
+ptype yes = int;
+token xyz;
+foo (yes) -> bar;
+bar (no) -> xyz;
+EOF
+    results = run_propane(capture: true)
+    expect(results.stderr).to match /Error: Line 4: ptype no not declared\. Declare with `ptype` statement\./
+    expect(results.status).to_not eq 0
+  end
+
+  it "warns on shift/reduce conflicts" do
+    write_grammar <<EOF
+token a;
+token b;
+Start -> As? b?;
+As -> a As2?;
+As2 -> b a As2?;
+EOF
+    results = run_propane(capture: true)
+    expect(results.stderr).to eq ""
+    expect(results.status).to eq 0
+    expect(File.binread("spec/run/testparser.log")).to match %r{Shift/Reduce conflict \(state \d+\) between token b and rule As2\? \(defined on line 4\)}
+  end
+
+  it "errors on shift/reduce conflicts with -w" do
+    write_grammar <<EOF
+token a;
+token b;
+Start -> As? b?;
+As -> a As2?;
+As2 -> b a As2?;
+EOF
+    results = run_propane(extra_args: %w[-w], capture: true)
+    expect(results.stderr).to match %r{Shift/Reduce conflict \(state \d+\) between token b and rule As2\? \(defined on line 4\)}m
+    expect(results.status).to_not eq 0
+    expect(File.binread("spec/run/testparser.log")).to match %r{Shift/Reduce conflict \(state \d+\) between token b and rule As2\? \(defined on line 4\)}
+  end
+
+  it "errors on duplicate field aliases in a rule" do
+    write_grammar <<EOF
+token a;
+token b;
+Start -> a:foo b:foo;
+EOF
+    results = run_propane(extra_args: %w[-w], capture: true)
+    expect(results.stderr).to match %r{Error: duplicate field alias `foo` for rule Start defined on line 3}
+    expect(results.status).to_not eq 0
+  end
+
+  it "errors when an alias is in different positions for different rules in a rule set when AST mode is enabled" do
+    write_grammar <<EOF
+ast;
+token a;
+token b;
+Start -> a:foo b;
+Start -> b b:foo;
+EOF
+    results = run_propane(extra_args: %w[-w], capture: true)
+    expect(results.stderr).to match %r{Error: conflicting AST node field positions for alias `foo`}
+    expect(results.status).to_not eq 0
+  end
+
+  it "does not error when an alias is in different positions for different rules in a rule set when AST mode is not enabled" do
+    write_grammar <<EOF
+token a;
+token b;
+Start -> a:foo b;
+Start -> b b:foo;
+EOF
+    results = run_propane(extra_args: %w[-w], capture: true)
+    expect(results.stderr).to eq ""
+    expect(results.status).to eq 0
+  end
+
   %w[d c].each do |language|
 
     context "#{language.upcase} language" do
@@ -126,9 +263,9 @@ Start -> Foo;
 Foo -> int <<>>
 Foo -> plus <<>>
 EOF
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_lexer.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -164,9 +301,9 @@ token int /\\d+/ <<
 Start -> int << $$ = $1; >>
 EOF
         end
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_lexer_unknown_character.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -184,7 +321,7 @@ E -> B;
 B -> zero;
 B -> one;
 EOF
-        build_parser(language: language)
+        run_propane(language: language)
       end
 
       it "generates a parser that does basic math - user guide example" do
@@ -258,9 +395,9 @@ E4 -> integer << $$ = $1; >>
 E4 -> lparen E1 rparen << $$ = $2; >>
 EOF
         end
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_basic_math_grammar.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -272,7 +409,7 @@ Start -> E;
 E -> one E;
 E -> one;
 EOF
-        build_parser(language: language)
+        run_propane(language: language)
       end
 
       it "distinguishes between multiple identical rules with lookahead symbol" do
@@ -284,9 +421,9 @@ Start -> R2 b;
 R1 -> a b;
 R2 -> a b;
 EOF
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_parser_identical_rules_lookahead.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.status).to eq 0
       end
 
@@ -299,9 +436,9 @@ Start -> a R1;
 Start -> b R1;
 R1 -> b;
 EOF
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_parser_rule_from_multiple_states.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.status).to eq 0
       end
 
@@ -334,9 +471,9 @@ Abcs -> ;
 Abcs -> abc Abcs;
 EOF
         end
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_user_code.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "abc!",
@@ -370,9 +507,9 @@ token abc;
 Start -> abc;
 EOF
         end
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_pattern.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "def!",
@@ -412,9 +549,9 @@ token abc;
 Start -> abc;
 EOF
         end
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_return_token_from_pattern.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "def!",
@@ -470,9 +607,9 @@ string: /"/ <<
 Start -> abc string def;
 EOF
         end
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_lexer_modes.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "begin string mode",
@@ -484,6 +621,62 @@ EOF
         ])
       end
 
+      it "multiple lexer modes may apply to a pattern" do
+        case language
+        when "c"
+          write_grammar <<EOF
+<<
+#include <stdio.h>
+>>
+ptype char;
+token abc;
+token def;
+default, identonly: token ident /[a-z]+/ <<
+  $$ = match[0];
+  $mode(default);
+  return $token(ident);
+>>
+token dot /\\./ <<
+  $mode(identonly);
+>>
+default, identonly: drop /\\s+/;
+Start -> abc dot ident <<
+  printf("ident: %c\\n", $3);
+>>
+EOF
+        when "d"
+          write_grammar <<EOF
+<<
+import std.stdio;
+>>
+ptype char;
+token abc;
+token def;
+default, identonly: token ident /[a-z]+/ <<
+  $$ = match[0];
+  $mode(default);
+>>
+token dot /\\./ <<
+  $mode(identonly);
+>>
+default, identonly: drop /\\s+/;
+Start -> abc dot ident <<
+  writeln("ident: ", $3);
+>>
+EOF
+        end
+        run_propane(language: language)
+        compile("spec/test_lexer_multiple_modes.#{language}", language: language)
+        results = run_test
+        expect(results.status).to eq 0
+        verify_lines(results.stdout, [
+          "ident: d",
+          "pass1",
+          "ident: a",
+          "pass2",
+        ])
+      end
+
       it "executes user code associated with a parser rule" do
         case language
         when "c"
@@ -509,9 +702,9 @@ A -> a << writeln("A!"); >>
 B -> b << writeln("B!"); >>
 EOF
         end
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_parser_rule_user_code.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "A!",
@@ -528,9 +721,9 @@ Start -> As << $$ = $1; >>
 As -> << $$ = 0u; >>
 As -> As a << $$ = $1 + 1u; >>
 EOF
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_parsing_lists.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.status).to eq 0
         expect(results.stderr).to eq ""
       end
@@ -549,9 +742,10 @@ Start -> b E d;
 E -> e;
 F -> e;
 EOF
-        results = build_parser(capture: true, language: language)
+        results = run_propane(capture: true, language: language)
         expect(results.status).to_not eq 0
-        expect(results.stderr).to match %r{reduce/reduce conflict.*\(E\).*\(F\)}
+        expect(results.stderr).to match %r{Error: reduce/reduce conflict \(state \d+\) between rule E#\d+ \(defined on line 10\) and rule F#\d+ \(defined on line 11\)}
+        expect(File.binread("spec/run/testparser.log")).to match %r{Reduce.actions:}
       end
 
       it "provides matched text to user code blocks" do
@@ -581,9 +775,9 @@ token id /[a-zA-Z_][a-zA-Z0-9_]*/ <<
 Start -> id;
 EOF
         end
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_lexer_match_text.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
           "Matched token is identifier_123",
@@ -614,9 +808,9 @@ Start -> word <<
 >>
 EOF
         end
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_lexer_result_value.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -629,16 +823,16 @@ drop /\\s+/;
 Start -> a num Start;
 Start -> a num;
 EOF
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_error_positions.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
 
       it "allows creating a JSON parser" do
         write_grammar(File.read("spec/json_parser.#{language}.propane"))
-        build_parser(language: language)
+        run_propane(language: language)
         compile(["spec/test_parsing_json.#{language}", "spec/json_types.#{language}"], language: language)
       end
 
@@ -650,16 +844,16 @@ token num /\\d+/;
 drop /\\s+/;
 Start -> a num;
 EOF
-        build_parser(name: "myp1", language: language)
+        run_propane(name: "myp1", language: language)
         write_grammar(<<EOF, name: "myp2")
 prefix myp2_;
 token b;
 token c;
 Start -> b c b;
 EOF
-        build_parser(name: "myp2", language: language)
+        run_propane(name: "myp2", language: language)
         compile("spec/test_multiple_parsers.#{language}", parsers: %w[myp1 myp2], language: language)
-        results = run
+        results = run_test
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -676,9 +870,9 @@ Any -> a;
 Any -> b;
 Any -> c;
 EOF
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_user_terminate_lexer.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -694,9 +888,9 @@ Any -> b Any << $terminate(4200); >>
 Any -> c Any;
 Any -> ;
 EOF
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_user_terminate.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
       end
@@ -738,9 +932,9 @@ tokenid t;
 Start -> t;
 EOF
         end
-        build_parser(language: language)
+        run_propane(language: language)
         compile("spec/test_match_backslashes.#{language}", language: language)
-        results = run
+        results = run_test
         expect(results.stderr).to eq ""
         expect(results.status).to eq 0
         verify_lines(results.stdout, [
@@ -765,7 +959,446 @@ Start -> ;
 Opt -> two;
 Opt -> ;
 EOF
-        build_parser(language: language)
+        run_propane(language: language)
+      end
+
+      it "generates an AST" do
+        write_grammar <<EOF
+ast;
+
+ptype int;
+
+token a << $$ = 11; >>
+token b << $$ = 22; >>
+token one /1/;
+token two /2/;
+token comma /,/ <<
+  $$ = 42;
+>>
+token lparen /\\(/;
+token rparen /\\)/;
+drop /\\s+/;
+
+Start -> Items;
+
+Items -> Item ItemsMore;
+Items -> ;
+
+ItemsMore -> comma Item ItemsMore;
+ItemsMore -> ;
+
+Item -> a;
+Item -> b;
+Item -> lparen Item rparen;
+Item -> Dual;
+
+Dual -> One Two;
+Dual -> Two One;
+One -> one;
+Two -> two;
+EOF
+        run_propane(language: language)
+        compile("spec/test_ast.#{language}", language: language)
+        results = run_test
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+      end
+
+      it "supports AST node prefix and suffix" do
+        write_grammar <<EOF
+ast;
+ast_prefix P ;
+ast_suffix  S;
+
+ptype int;
+
+token a << $$ = 11; >>
+token b << $$ = 22; >>
+token one /1/;
+token two /2/;
+token comma /,/ <<
+  $$ = 42;
+>>
+token lparen /\\(/;
+token rparen /\\)/;
+drop /\\s+/;
+
+Start -> Items;
+
+Items -> Item ItemsMore;
+Items -> ;
+
+ItemsMore -> comma Item ItemsMore;
+ItemsMore -> ;
+
+Item -> a;
+Item -> b;
+Item -> lparen Item rparen;
+Item -> Dual;
+
+Dual -> One Two;
+Dual -> Two One;
+One -> one;
+Two -> two;
+EOF
+        run_propane(language: language)
+        compile("spec/test_ast_ps.#{language}", language: language)
+        results = run_test
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+      end
+
+      it "allows specifying a different start rule" do
+        write_grammar <<EOF
+token hi;
+start Top;
+Top -> hi;
+EOF
+        run_propane(language: language)
+        compile("spec/test_start_rule.#{language}", language: language)
+      end
+
+      it "allows specifying a different start rule with AST generation" do
+        write_grammar <<EOF
+ast;
+token hi;
+start Top;
+Top -> hi;
+EOF
+        run_propane(language: language)
+        compile("spec/test_start_rule_ast.#{language}", language: language)
+      end
+
+      it "allows marking a rule component as optional" do
+        if language == "d"
+          write_grammar <<EOF
+<<
+import std.stdio;
+>>
+
+ptype int;
+ptype float = float;
+ptype string = string;
+
+token a (float) << $$ = 1.5; >>
+token b << $$ = 2; >>
+token c << $$ = 3; >>
+token d << $$ = 4; >>
+Start -> a? b R? <<
+  writeln("a: ", $1);
+  writeln("b: ", $2);
+  writeln("R: ", $3);
+>>
+R -> c d << $$ = "cd"; >>
+R (string) -> d c << $$ = "dc"; >>
+EOF
+        else
+          write_grammar <<EOF
+<<
+#include <stdio.h>
+>>
+
+ptype int;
+ptype float = float;
+ptype string = char *;
+
+token a (float) << $$ = 1.5; >>
+token b << $$ = 2; >>
+token c << $$ = 3; >>
+token d << $$ = 4; >>
+Start -> a? b R? <<
+  printf("a: %.1f\\n", $1);
+  printf("b: %d\\n", $2);
+  printf("R: %s\\n", $3 == NULL ? "" : $3);
+>>
+R -> c d << $$ = "cd"; >>
+R (string) -> d c << $$ = "dc"; >>
+EOF
+        end
+        run_propane(language: language)
+        compile("spec/test_optional_rule_component.#{language}", language: language)
+        results = run_test
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+        verify_lines(results.stdout, [
+          "a: 0#{language == "d" ? "" : ".0"}",
+          "b: 2",
+          "R: ",
+          "a: 1.5",
+          "b: 2",
+          "R: cd",
+          "a: 1.5",
+          "b: 2",
+          "R: dc",
+        ])
+      end
+
+      it "allows marking a rule component as optional in AST generation mode" do
+        if language == "d"
+          write_grammar <<EOF
+ast;
+
+<<
+import std.stdio;
+>>
+
+token a;
+token b;
+token c;
+token d;
+Start -> a? b R?;
+R -> c d;
+R -> d c;
+EOF
+        else
+          write_grammar <<EOF
+ast;
+
+<<
+#include <stdio.h>
+>>
+
+token a;
+token b;
+token c;
+token d;
+Start -> a? b R?;
+R -> c d;
+R -> d c;
+EOF
+        end
+        run_propane(language: language)
+        compile("spec/test_optional_rule_component_ast.#{language}", language: language)
+        results = run_test
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+      end
+
+      it "allows naming an optional rule component in AST generation mode" do
+        if language == "d"
+          write_grammar <<EOF
+ast;
+
+<<
+import std.stdio;
+>>
+
+token a;
+token b;
+token c;
+token d;
+Start -> a?:a b R?:r;
+R -> c d;
+R -> d c;
+EOF
+        else
+          write_grammar <<EOF
+ast;
+
+<<
+#include <stdio.h>
+>>
+
+token a;
+token b;
+token c;
+token d;
+Start -> a?:a b R?:r;
+R -> c d;
+R -> d c;
+EOF
+        end
+        run_propane(language: language)
+        compile("spec/test_named_optional_rule_component_ast.#{language}", language: language)
+        results = run_test
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+      end
+
+      it "stores token and rule positions in AST nodes" do
+        write_grammar <<EOF
+ast;
+
+token a;
+token bb;
+token c /c(.|\\n)*c/;
+drop /\\s+/;
+Start -> T T T;
+T -> a;
+T -> bb;
+T -> c;
+EOF
+        run_propane(language: language)
+        compile("spec/test_ast_token_positions.#{language}", language: language)
+        results = run_test
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+      end
+
+      it "stores invalid positions for empty rule matches" do
+        write_grammar <<EOF
+ast;
+
+token a;
+token bb;
+token c /c(.|\\n)*c/;
+drop /\\s+/;
+Start -> T Start;
+Start -> ;
+T -> a A;
+A -> bb? c?;
+EOF
+        run_propane(language: language)
+        compile("spec/test_ast_invalid_positions.#{language}", language: language)
+        results = run_test
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+      end
+
+      it "allows specifying field aliases in AST mode" do
+        write_grammar <<EOF
+ast;
+
+token a;
+token b;
+token c;
+drop /\\s+/;
+Start -> T:first T:second T:third;
+T -> a;
+T -> b;
+T -> c;
+EOF
+        run_propane(language: language)
+        compile("spec/test_ast_field_aliases.#{language}", language: language)
+        results = run_test
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+      end
+
+      it "aliases the correct field when multiple rules are in a rule set in AST mode" do
+        write_grammar <<EOF
+ast;
+
+token a;
+token b;
+token c;
+drop /\\s+/;
+Start -> a;
+Start -> Foo;
+Start -> T:first T:second T:third;
+Foo -> b;
+T -> a;
+T -> b;
+T -> c;
+EOF
+        run_propane(language: language)
+        compile("spec/test_ast_field_aliases.#{language}", language: language)
+        results = run_test
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+      end
+
+      it "allows specifying field aliases when AST mode is not enabled" do
+        if language == "d"
+          write_grammar <<EOF
+<<
+import std.stdio;
+>>
+ptype string;
+token id /[a-zA-Z_][a-zA-Z0-9_]*/ <<
+  $$ = match;
+>>
+drop /\\s+/;
+Start -> id:first id:second <<
+  writeln("first is ", ${first});
+  writeln("second is ", ${second});
+>>
+EOF
+        else
+          write_grammar <<EOF
+<<
+#include <stdio.h>
+#include <string.h>
+>>
+ptype char const *;
+token id /[a-zA-Z_][a-zA-Z0-9_]*/ <<
+  char * s = malloc(match_length + 1);
+  strncpy(s, (char const *)match, match_length);
+  s[match_length] = 0;
+  $$ = s;
+>>
+drop /\\s+/;
+Start -> id:first id:second <<
+  printf("first is %s\\n", ${first});
+  printf("second is %s\\n", ${second});
+>>
+EOF
+        end
+        run_propane(language: language)
+        compile("spec/test_field_aliases.#{language}", language: language)
+        results = run_test
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+        expect(results.stdout).to match /first is foo1.*second is bar2/m
+      end
+
+      it "aliases the correct field when multiple rules are in a rule set when AST mode is not enabled" do
+        if language == "d"
+          write_grammar <<EOF
+<<
+import std.stdio;
+>>
+ptype string;
+token id /[a-zA-Z_][a-zA-Z0-9_]*/ <<
+  $$ = match;
+>>
+drop /\\s+/;
+Start -> id;
+Start -> Foo;
+Start -> id:first id:second <<
+  writeln("first is ", ${first});
+  writeln("second is ", ${second});
+>>
+Foo -> ;
+EOF
+        else
+          write_grammar <<EOF
+<<
+#include <stdio.h>
+#include <string.h>
+>>
+ptype char const *;
+token id /[a-zA-Z_][a-zA-Z0-9_]*/ <<
+  char * s = malloc(match_length + 1);
+  strncpy(s, (char const *)match, match_length);
+  s[match_length] = 0;
+  $$ = s;
+>>
+drop /\\s+/;
+Start -> id;
+Start -> Foo;
+Start -> id:first id:second <<
+  printf("first is %s\\n", ${first});
+  printf("second is %s\\n", ${second});
+>>
+Foo -> ;
+EOF
+        end
+        run_propane(language: language)
+        compile("spec/test_field_aliases.#{language}", language: language)
+        results = run_test
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
+        expect(results.stdout).to match /first is foo1.*second is bar2/m
+      end
+
+      it "does not free memory allocated for AST nodes" do
+        write_grammar(File.read("spec/ast_node_memory_remains.#{language}.propane"))
+        run_propane(language: language)
+        compile("spec/test_ast_node_memory_remains.#{language}", language: language)
+        results = run_test
+        expect(results.stderr).to eq ""
+        expect(results.status).to eq 0
       end
     end
   end

spec/test_ast.c

@@ -0,0 +1,55 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "a, ((b)), b";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert_eq(P_SUCCESS, p_parse(&context));
+    Start * start = p_result(&context);
+    assert(start->pItems1 != NULL);
+    assert(start->pItems != NULL);
+    Items * items = start->pItems;
+    assert(items->pItem != NULL);
+    assert(items->pItem->pToken1 != NULL);
+    assert_eq(TOKEN_a, items->pItem->pToken1->token);
+    assert_eq(11, items->pItem->pToken1->pvalue);
+    assert(items->pItemsMore != NULL);
+    ItemsMore * itemsmore = items->pItemsMore;
+    assert(itemsmore->pItem != NULL);
+    assert(itemsmore->pItem->pItem != NULL);
+    assert(itemsmore->pItem->pItem->pItem != NULL);
+    assert(itemsmore->pItem->pItem->pItem->pToken1 != NULL);
+    assert_eq(TOKEN_b, itemsmore->pItem->pItem->pItem->pToken1->token);
+    assert_eq(22, itemsmore->pItem->pItem->pItem->pToken1->pvalue);
+    assert(itemsmore->pItemsMore != NULL);
+    itemsmore = itemsmore->pItemsMore;
+    assert(itemsmore->pItem != NULL);
+    assert(itemsmore->pItem->pToken1 != NULL);
+    assert_eq(TOKEN_b, itemsmore->pItem->pToken1->token);
+    assert_eq(22, itemsmore->pItem->pToken1->pvalue);
+    assert(itemsmore->pItemsMore == NULL);
+
+    input = "";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert_eq(P_SUCCESS, p_parse(&context));
+    start = p_result(&context);
+    assert(start->pItems == NULL);
+
+    input = "2 1";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert_eq(P_SUCCESS, p_parse(&context));
+    start = p_result(&context);
+    assert(start->pItems != NULL);
+    assert(start->pItems->pItem != NULL);
+    assert(start->pItems->pItem->pDual != NULL);
+    assert(start->pItems->pItem->pDual->pTwo1 != NULL);
+    assert(start->pItems->pItem->pDual->pOne2 != NULL);
+    assert(start->pItems->pItem->pDual->pTwo2 == NULL);
+    assert(start->pItems->pItem->pDual->pOne1 == NULL);
+
+    return 0;
+}

spec/test_ast.d

@@ -0,0 +1,57 @@
+import testparser;
+import std.stdio;
+import testutils;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "a, ((b)), b";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert_eq(P_SUCCESS, p_parse(&context));
+    Start * start = p_result(&context);
+    assert(start.pItems1 !is null);
+    assert(start.pItems !is null);
+    Items * items = start.pItems;
+    assert(items.pItem !is null);
+    assert(items.pItem.pToken1 !is null);
+    assert_eq(TOKEN_a, items.pItem.pToken1.token);
+    assert_eq(11, items.pItem.pToken1.pvalue);
+    assert(items.pItemsMore !is null);
+    ItemsMore * itemsmore = items.pItemsMore;
+    assert(itemsmore.pItem !is null);
+    assert(itemsmore.pItem.pItem !is null);
+    assert(itemsmore.pItem.pItem.pItem !is null);
+    assert(itemsmore.pItem.pItem.pItem.pToken1 !is null);
+    assert_eq(TOKEN_b, itemsmore.pItem.pItem.pItem.pToken1.token);
+    assert_eq(22, itemsmore.pItem.pItem.pItem.pToken1.pvalue);
+    assert(itemsmore.pItemsMore !is null);
+    itemsmore = itemsmore.pItemsMore;
+    assert(itemsmore.pItem !is null);
+    assert(itemsmore.pItem.pToken1 !is null);
+    assert_eq(TOKEN_b, itemsmore.pItem.pToken1.token);
+    assert_eq(22, itemsmore.pItem.pToken1.pvalue);
+    assert(itemsmore.pItemsMore is null);
+
+    input = "";
+    p_context_init(&context, input);
+    assert_eq(P_SUCCESS, p_parse(&context));
+    start = p_result(&context);
+    assert(start.pItems is null);
+
+    input = "2 1";
+    p_context_init(&context, input);
+    assert_eq(P_SUCCESS, p_parse(&context));
+    start = p_result(&context);
+    assert(start.pItems !is null);
+    assert(start.pItems.pItem !is null);
+    assert(start.pItems.pItem.pDual !is null);
+    assert(start.pItems.pItem.pDual.pTwo1 !is null);
+    assert(start.pItems.pItem.pDual.pOne2 !is null);
+    assert(start.pItems.pItem.pDual.pTwo2 is null);
+    assert(start.pItems.pItem.pDual.pOne1 is null);
+}

spec/test_ast_field_aliases.c

@@ -0,0 +1,19 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "\na\nb\nc";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    Start * start = p_result(&context);
+
+    assert_eq(TOKEN_a, start->first->pToken->token);
+    assert_eq(TOKEN_b, start->second->pToken->token);
+    assert_eq(TOKEN_c, start->third->pToken->token);
+
+    return 0;
+}

spec/test_ast_field_aliases.d

@@ -0,0 +1,21 @@
+import testparser;
+import std.stdio;
+import testutils;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "\na\nb\nc";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    Start * start = p_result(&context);
+
+    assert_eq(TOKEN_a, start.first.pToken.token);
+    assert_eq(TOKEN_b, start.second.pToken.token);
+    assert_eq(TOKEN_c, start.third.pToken.token);
+}

spec/test_ast_invalid_positions.c

@@ -0,0 +1,102 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "\na\n  bb ccc";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    Start * start = p_result(&context);
+
+    assert_eq(2, start->pT1->pToken->position.row);
+    assert_eq(1, start->pT1->pToken->position.col);
+    assert_eq(2, start->pT1->pToken->end_position.row);
+    assert_eq(1, start->pT1->pToken->end_position.col);
+    assert(p_position_valid(start->pT1->pA->position));
+    assert_eq(3, start->pT1->pA->position.row);
+    assert_eq(3, start->pT1->pA->position.col);
+    assert_eq(3, start->pT1->pA->end_position.row);
+    assert_eq(8, start->pT1->pA->end_position.col);
+    assert_eq(2, start->pT1->position.row);
+    assert_eq(1, start->pT1->position.col);
+    assert_eq(3, start->pT1->end_position.row);
+    assert_eq(8, start->pT1->end_position.col);
+
+    assert_eq(2, start->position.row);
+    assert_eq(1, start->position.col);
+    assert_eq(3, start->end_position.row);
+    assert_eq(8, start->end_position.col);
+
+    input = "a\nbb";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+
+    assert_eq(1, start->pT1->pToken->position.row);
+    assert_eq(1, start->pT1->pToken->position.col);
+    assert_eq(1, start->pT1->pToken->end_position.row);
+    assert_eq(1, start->pT1->pToken->end_position.col);
+    assert(p_position_valid(start->pT1->pA->position));
+    assert_eq(2, start->pT1->pA->position.row);
+    assert_eq(1, start->pT1->pA->position.col);
+    assert_eq(2, start->pT1->pA->end_position.row);
+    assert_eq(2, start->pT1->pA->end_position.col);
+    assert_eq(1, start->pT1->position.row);
+    assert_eq(1, start->pT1->position.col);
+    assert_eq(2, start->pT1->end_position.row);
+    assert_eq(2, start->pT1->end_position.col);
+
+    assert_eq(1, start->position.row);
+    assert_eq(1, start->position.col);
+    assert_eq(2, start->end_position.row);
+    assert_eq(2, start->end_position.col);
+
+    input = "a\nc\nc";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+
+    assert_eq(1, start->pT1->pToken->position.row);
+    assert_eq(1, start->pT1->pToken->position.col);
+    assert_eq(1, start->pT1->pToken->end_position.row);
+    assert_eq(1, start->pT1->pToken->end_position.col);
+    assert(p_position_valid(start->pT1->pA->position));
+    assert_eq(2, start->pT1->pA->position.row);
+    assert_eq(1, start->pT1->pA->position.col);
+    assert_eq(3, start->pT1->pA->end_position.row);
+    assert_eq(1, start->pT1->pA->end_position.col);
+    assert_eq(1, start->pT1->position.row);
+    assert_eq(1, start->pT1->position.col);
+    assert_eq(3, start->pT1->end_position.row);
+    assert_eq(1, start->pT1->end_position.col);
+
+    assert_eq(1, start->position.row);
+    assert_eq(1, start->position.col);
+    assert_eq(3, start->end_position.row);
+    assert_eq(1, start->end_position.col);
+
+    input = "a";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+
+    assert_eq(1, start->pT1->pToken->position.row);
+    assert_eq(1, start->pT1->pToken->position.col);
+    assert_eq(1, start->pT1->pToken->end_position.row);
+    assert_eq(1, start->pT1->pToken->end_position.col);
+    assert(!p_position_valid(start->pT1->pA->position));
+    assert_eq(1, start->pT1->position.row);
+    assert_eq(1, start->pT1->position.col);
+    assert_eq(1, start->pT1->end_position.row);
+    assert_eq(1, start->pT1->end_position.col);
+
+    assert_eq(1, start->position.row);
+    assert_eq(1, start->position.col);
+    assert_eq(1, start->end_position.row);
+    assert_eq(1, start->end_position.col);
+
+    return 0;
+}

spec/test_ast_invalid_positions.d

@@ -0,0 +1,104 @@
+import testparser;
+import std.stdio;
+import testutils;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "\na\n  bb ccc";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    Start * start = p_result(&context);
+
+    assert_eq(2, start.pT1.pToken.position.row);
+    assert_eq(1, start.pT1.pToken.position.col);
+    assert_eq(2, start.pT1.pToken.end_position.row);
+    assert_eq(1, start.pT1.pToken.end_position.col);
+    assert(start.pT1.pA.position.valid);
+    assert_eq(3, start.pT1.pA.position.row);
+    assert_eq(3, start.pT1.pA.position.col);
+    assert_eq(3, start.pT1.pA.end_position.row);
+    assert_eq(8, start.pT1.pA.end_position.col);
+    assert_eq(2, start.pT1.position.row);
+    assert_eq(1, start.pT1.position.col);
+    assert_eq(3, start.pT1.end_position.row);
+    assert_eq(8, start.pT1.end_position.col);
+
+    assert_eq(2, start.position.row);
+    assert_eq(1, start.position.col);
+    assert_eq(3, start.end_position.row);
+    assert_eq(8, start.end_position.col);
+
+    input = "a\nbb";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+
+    assert_eq(1, start.pT1.pToken.position.row);
+    assert_eq(1, start.pT1.pToken.position.col);
+    assert_eq(1, start.pT1.pToken.end_position.row);
+    assert_eq(1, start.pT1.pToken.end_position.col);
+    assert(start.pT1.pA.position.valid);
+    assert_eq(2, start.pT1.pA.position.row);
+    assert_eq(1, start.pT1.pA.position.col);
+    assert_eq(2, start.pT1.pA.end_position.row);
+    assert_eq(2, start.pT1.pA.end_position.col);
+    assert_eq(1, start.pT1.position.row);
+    assert_eq(1, start.pT1.position.col);
+    assert_eq(2, start.pT1.end_position.row);
+    assert_eq(2, start.pT1.end_position.col);
+
+    assert_eq(1, start.position.row);
+    assert_eq(1, start.position.col);
+    assert_eq(2, start.end_position.row);
+    assert_eq(2, start.end_position.col);
+
+    input = "a\nc\nc";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+
+    assert_eq(1, start.pT1.pToken.position.row);
+    assert_eq(1, start.pT1.pToken.position.col);
+    assert_eq(1, start.pT1.pToken.end_position.row);
+    assert_eq(1, start.pT1.pToken.end_position.col);
+    assert(start.pT1.pA.position.valid);
+    assert_eq(2, start.pT1.pA.position.row);
+    assert_eq(1, start.pT1.pA.position.col);
+    assert_eq(3, start.pT1.pA.end_position.row);
+    assert_eq(1, start.pT1.pA.end_position.col);
+    assert_eq(1, start.pT1.position.row);
+    assert_eq(1, start.pT1.position.col);
+    assert_eq(3, start.pT1.end_position.row);
+    assert_eq(1, start.pT1.end_position.col);
+
+    assert_eq(1, start.position.row);
+    assert_eq(1, start.position.col);
+    assert_eq(3, start.end_position.row);
+    assert_eq(1, start.end_position.col);
+
+    input = "a";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+
+    assert_eq(1, start.pT1.pToken.position.row);
+    assert_eq(1, start.pT1.pToken.position.col);
+    assert_eq(1, start.pT1.pToken.end_position.row);
+    assert_eq(1, start.pT1.pToken.end_position.col);
+    assert(!start.pT1.pA.position.valid);
+    assert_eq(1, start.pT1.position.row);
+    assert_eq(1, start.pT1.position.col);
+    assert_eq(1, start.pT1.end_position.row);
+    assert_eq(1, start.pT1.end_position.col);
+
+    assert_eq(1, start.position.row);
+    assert_eq(1, start.position.col);
+    assert_eq(1, start.end_position.row);
+    assert_eq(1, start.end_position.col);
+}

spec/test_ast_node_memory_remains.c

@@ -0,0 +1,415 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+#include "testutils.h"
+
+int main(int argc, char * argv[])
+{
+    const char * input =
+        "# 0\n"
+        "def byte_val() -> byte\n"
+        "{\n"
+        "    return 0x42;\n"
+        "}\n"
+        "\n"
+        "# 1\n"
+        "def short_val() -> short\n"
+        "{\n"
+        "    return 0x4242;\n"
+        "}\n"
+        "\n"
+        "# 2\n"
+        "def int_val() -> int\n"
+        "{\n"
+        "    return 0x42424242;\n"
+        "}\n"
+        "\n"
+        "# 3\n"
+        "def long_val() -> long\n"
+        "{\n"
+        "    return 0x4242_4242_4242_4242;\n"
+        "}\n"
+        "\n"
+        "# 4\n"
+        "def ssize_t_val() -> ssize_t\n"
+        "{\n"
+        "    return 0x42424242;\n"
+        "}\n"
+        "\n"
+        "# 5\n"
+        "def byte_to_short() -> short\n"
+        "{\n"
+        "    return byte_val();\n"
+        "}\n"
+        "\n"
+        "# 6\n"
+        "def byte_to_int() -> int\n"
+        "{\n"
+        "    return byte_val();\n"
+        "}\n"
+        "\n"
+        "# 7\n"
+        "def byte_to_long() -> long\n"
+        "{\n"
+        "    return byte_val();\n"
+        "}\n"
+        "\n"
+        "# 8\n"
+        "def byte_to_ssize_t() -> ssize_t\n"
+        "{\n"
+        "    return byte_val();\n"
+        "}\n"
+        "\n"
+        "# 9\n"
+        "def short_to_byte() -> byte\n"
+        "{\n"
+        "    return short_val();\n"
+        "}\n"
+        "\n"
+        "# 10\n"
+        "def short_to_int() -> int\n"
+        "{\n"
+        "    return short_val();\n"
+        "}\n"
+        "\n"
+        "# 11\n"
+        "def short_to_long() -> long\n"
+        "{\n"
+        "    return short_val();\n"
+        "}\n"
+        "\n"
+        "# 12\n"
+        "def short_to_ssize_t() -> ssize_t\n"
+        "{\n"
+        "    return short_val();\n"
+        "}\n"
+        "\n"
+        "# 13\n"
+        "def int_to_byte() -> byte\n"
+        "{\n"
+        "    return int_val();\n"
+        "}\n"
+        "\n"
+        "# 14\n"
+        "def int_to_short() -> short\n"
+        "{\n"
+        "    return int_val();\n"
+        "}\n"
+        "\n"
+        "# 15\n"
+        "def int_to_long() -> long\n"
+        "{\n"
+        "    return int_val();\n"
+        "}\n"
+        "\n"
+        "# 16\n"
+        "def int_to_ssize_t() -> ssize_t\n"
+        "{\n"
+        "    return int_val();\n"
+        "}\n"
+        "\n"
+        "# 17\n"
+        "def long_to_byte() -> byte\n"
+        "{\n"
+        "    return long_val();\n"
+        "}\n"
+        "\n"
+        "# 18\n"
+        "def long_to_short() -> short\n"
+        "{\n"
+        "    return long_val();\n"
+        "}\n"
+        "\n"
+        "# 19\n"
+        "def long_to_int() -> int\n"
+        "{\n"
+        "    return long_val();\n"
+        "}\n"
+        "\n"
+        "# 20\n"
+        "def long_to_ssize_t() -> ssize_t\n"
+        "{\n"
+        "    return long_val();\n"
+        "}\n"
+        "\n"
+        "# 21\n"
+        "def ssize_t_to_byte() -> byte\n"
+        "{\n"
+        "    return ssize_t_val();\n"
+        "}\n"
+        "\n"
+        "# 22\n"
+        "def ssize_t_to_short() -> short\n"
+        "{\n"
+        "    return ssize_t_val();\n"
+        "}\n"
+        "\n"
+        "# 23\n"
+        "def ssize_t_to_int() -> int\n"
+        "{\n"
+        "    return ssize_t_val();\n"
+        "}\n"
+        "\n"
+        "# 24\n"
+        "def ssize_t_to_long() -> long\n"
+        "{\n"
+        "    return ssize_t_val();\n"
+        "}\n"
+        "\n"
+        "# 25\n"
+        "def ubyte_val() -> ubyte\n"
+        "{\n"
+        "    return 0x42;\n"
+        "}\n"
+        "\n"
+        "# 26\n"
+        "def ushort_val() -> ushort\n"
+        "{\n"
+        "    return 0x4242;\n"
+        "}\n"
+        "\n"
+        "# 27\n"
+        "def uint_val() -> uint\n"
+        "{\n"
+        "    return 0x42424242;\n"
+        "}\n"
+        "\n"
+        "# 28\n"
+        "def ulong_val() -> ulong\n"
+        "{\n"
+        "    return 0x4242_4242_4242_4242;\n"
+        "}\n"
+        "\n"
+        "# 29\n"
+        "def size_t_val() -> size_t\n"
+        "{\n"
+        "    return 0x42424242;\n"
+        "}\n"
+        "\n"
+        "# 30\n"
+        "def ubyte_to_ushort() -> ushort\n"
+        "{\n"
+        "    return ubyte_val();\n"
+        "}\n"
+        "\n"
+        "# 31\n"
+        "def ubyte_to_uint() -> uint\n"
+        "{\n"
+        "    return ubyte_val();\n"
+        "}\n"
+        "\n"
+        "# 32\n"
+        "def ubyte_to_ulong() -> ulong\n"
+        "{\n"
+        "    return ubyte_val();\n"
+        "}\n"
+        "\n"
+        "# 33\n"
+        "def ubyte_to_size_t() -> size_t\n"
+        "{\n"
+        "    return ubyte_val();\n"
+        "}\n"
+        "\n"
+        "# 34\n"
+        "def ushort_to_ubyte() -> ubyte\n"
+        "{\n"
+        "    return ushort_val();\n"
+        "}\n"
+        "\n"
+        "# 35\n"
+        "def ushort_to_uint() -> uint\n"
+        "{\n"
+        "    return ushort_val();\n"
+        "}\n"
+        "\n"
+        "# 36\n"
+        "def ushort_to_ulong() -> ulong\n"
+        "{\n"
+        "    return ushort_val();\n"
+        "}\n"
+        "\n"
+        "# 37\n"
+        "def ushort_to_size_t() -> size_t\n"
+        "{\n"
+        "    return ushort_val();\n"
+        "}\n"
+        "\n"
+        "# 38\n"
+        "def uint_to_ubyte() -> ubyte\n"
+        "{\n"
+        "    return uint_val();\n"
+        "}\n"
+        "\n"
+        "# 39\n"
+        "def uint_to_ushort() -> ushort\n"
+        "{\n"
+        "    return uint_val();\n"
+        "}\n"
+        "\n"
+        "# 40\n"
+        "def uint_to_ulong() -> ulong\n"
+        "{\n"
+        "    return uint_val();\n"
+        "}\n"
+        "\n"
+        "# 41\n"
+        "def uint_to_size_t() -> size_t\n"
+        "{\n"
+        "    return uint_val();\n"
+        "}\n"
+        "\n"
+        "# 42\n"
+        "def ulong_to_ubyte() -> ubyte\n"
+        "{\n"
+        "    return ulong_val();\n"
+        "}\n"
+        "\n"
+        "# 43\n"
+        "def ulong_to_ushort() -> ushort\n"
+        "{\n"
+        "    return ulong_val();\n"
+        "}\n"
+        "\n"
+        "# 44\n"
+        "def ulong_to_uint() -> uint\n"
+        "{\n"
+        "    return ulong_val();\n"
+        "}\n"
+        "\n"
+        "# 45\n"
+        "def ulong_to_size_t() -> size_t\n"
+        "{\n"
+        "    return ulong_val();\n"
+        "}\n"
+        "\n"
+        "# 46\n"
+        "def size_t_to_ubyte() -> ubyte\n"
+        "{\n"
+        "    return size_t_val();\n"
+        "}\n"
+        "\n"
+        "# 47\n"
+        "def size_t_to_ushort() -> ushort\n"
+        "{\n"
+        "    return size_t_val();\n"
+        "}\n"
+        "\n"
+        "# 48\n"
+        "def size_t_to_int() -> int\n"
+        "{\n"
+        "    return size_t_val();\n"
+        "}\n"
+        "\n"
+        "# 49\n"
+        "def size_t_to_ulong() -> ulong\n"
+        "{\n"
+        "    return size_t_val();\n"
+        "}\n"
+        "\n"
+        "# 50\n"
+        "def main() -> int\n"
+        "{\n"
+        "    return int_val();\n"
+        "}\n";
+    struct
+    {
+        const char * name;
+        p_token_t token;
+    } expected[] = {
+        {"byte_val", TOKEN_byte},
+        {"short_val", TOKEN_short},
+        {"int_val", TOKEN_int},
+        {"long_val", TOKEN_long},
+        {"ssize_t_val", TOKEN_ssize_t},
+        {"byte_to_short", TOKEN_short},
+        {"byte_to_int", TOKEN_int},
+        {"byte_to_long", TOKEN_long},
+        {"byte_to_ssize_t", TOKEN_ssize_t},
+        {"short_to_byte", TOKEN_byte},
+        {"short_to_int", TOKEN_int},
+        {"short_to_long", TOKEN_long},
+        {"short_to_ssize_t", TOKEN_ssize_t},
+        {"int_to_byte", TOKEN_byte},
+        {"int_to_short", TOKEN_short},
+        {"int_to_long", TOKEN_long},
+        {"int_to_ssize_t", TOKEN_ssize_t},
+        {"long_to_byte", TOKEN_byte},
+        {"long_to_short", TOKEN_short},
+        {"long_to_int", TOKEN_int},
+        {"long_to_ssize_t", TOKEN_ssize_t},
+        {"ssize_t_to_byte", TOKEN_byte},
+        {"ssize_t_to_short", TOKEN_short},
+        {"ssize_t_to_int", TOKEN_int},
+        {"ssize_t_to_long", TOKEN_long},
+        {"ubyte_val", TOKEN_ubyte},
+        {"ushort_val", TOKEN_ushort},
+        {"uint_val", TOKEN_uint},
+        {"ulong_val", TOKEN_ulong},
+        {"size_t_val", TOKEN_size_t},
+        {"ubyte_to_ushort", TOKEN_ushort},
+        {"ubyte_to_uint", TOKEN_uint},
+        {"ubyte_to_ulong", TOKEN_ulong},
+        {"ubyte_to_size_t", TOKEN_size_t},
+        {"ushort_to_ubyte", TOKEN_ubyte},
+        {"ushort_to_uint", TOKEN_uint},
+        {"ushort_to_ulong", TOKEN_ulong},
+        {"ushort_to_size_t", TOKEN_size_t},
+        {"uint_to_ubyte", TOKEN_ubyte},
+        {"uint_to_ushort", TOKEN_ushort},
+        {"uint_to_ulong", TOKEN_ulong},
+        {"uint_to_size_t", TOKEN_size_t},
+        {"ulong_to_ubyte", TOKEN_ubyte},
+        {"ulong_to_ushort", TOKEN_ushort},
+        {"ulong_to_uint", TOKEN_uint},
+        {"ulong_to_size_t", TOKEN_size_t},
+        {"size_t_to_ubyte", TOKEN_ubyte},
+        {"size_t_to_ushort", TOKEN_ushort},
+        {"size_t_to_int", TOKEN_int},
+        {"size_t_to_ulong", TOKEN_ulong},
+        {"main", TOKEN_int},
+    };
+    p_context_t context;
+    p_context_init(&context, (const uint8_t *)input, strlen(input));
+    size_t result = p_parse(&context);
+    assert_eq(P_SUCCESS, result);
+    PModule * pmod = p_result(&context);
+    PModuleItems * pmis = pmod->pModuleItems;
+    PFunctionDefinition ** pfds;
+    size_t n_pfds = 0u;
+    while (pmis != NULL)
+    {
+        PModuleItem * pmi = pmis->pModuleItem;
+        if (pmi->pFunctionDefinition != NULL)
+        {
+            n_pfds++;
+        }
+        pmis = pmis->pModuleItems;
+    }
+    pfds = malloc(n_pfds * sizeof(PModuleItems *));
+    pmis = pmod->pModuleItems;
+    size_t pfd_i = n_pfds;
+    while (pmis != NULL)
+    {
+        PModuleItem * pmi = pmis->pModuleItem;
+        PFunctionDefinition * pfd = pmi->pFunctionDefinition;
+        if (pfd != NULL)
+        {
+            pfd_i--;
+            assert(pfd_i < n_pfds);
+            pfds[pfd_i] = pfd;
+        }
+        pmis = pmis->pModuleItems;
+    }
+    assert_eq(51, n_pfds);
+    for (size_t i = 0; i < n_pfds; i++)
+    {
+        if (strncmp(expected[i].name, (const char *)pfds[i]->name->pvalue.s, strlen(expected[i].name)) != 0 ||
+            (expected[i].token != pfds[i]->returntype->pType->pTypeBase->pToken1->token))
+        {
+            fprintf(stderr, "Index %lu: expected %s/%u, got %u\n", i, expected[i].name, expected[i].token, pfds[i]->returntype->pType->pTypeBase->pToken1->token);
+        }
+    }
+
+    return 0;
+}

spec/test_ast_node_memory_remains.d

@@ -0,0 +1,408 @@
+import testparser;
+import std.stdio;
+import testutils;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "
+# 0
+def byte_val() -> byte
+{
+    return 0x42;
+}
+
+# 1
+def short_val() -> short
+{
+    return 0x4242;
+}
+
+# 2
+def int_val() -> int
+{
+    return 0x42424242;
+}
+
+# 3
+def long_val() -> long
+{
+    return 0x4242_4242_4242_4242;
+}
+
+# 4
+def ssize_t_val() -> ssize_t
+{
+    return 0x42424242;
+}
+
+# 5
+def byte_to_short() -> short
+{
+    return byte_val();
+}
+
+# 6
+def byte_to_int() -> int
+{
+    return byte_val();
+}
+
+# 7
+def byte_to_long() -> long
+{
+    return byte_val();
+}
+
+# 8
+def byte_to_ssize_t() -> ssize_t
+{
+    return byte_val();
+}
+
+# 9
+def short_to_byte() -> byte
+{
+    return short_val();
+}
+
+# 10
+def short_to_int() -> int
+{
+    return short_val();
+}
+
+# 11
+def short_to_long() -> long
+{
+    return short_val();
+}
+
+# 12
+def short_to_ssize_t() -> ssize_t
+{
+    return short_val();
+}
+
+# 13
+def int_to_byte() -> byte
+{
+    return int_val();
+}
+
+# 14
+def int_to_short() -> short
+{
+    return int_val();
+}
+
+# 15
+def int_to_long() -> long
+{
+    return int_val();
+}
+
+# 16
+def int_to_ssize_t() -> ssize_t
+{
+    return int_val();
+}
+
+# 17
+def long_to_byte() -> byte
+{
+    return long_val();
+}
+
+# 18
+def long_to_short() -> short
+{
+    return long_val();
+}
+
+# 19
+def long_to_int() -> int
+{
+    return long_val();
+}
+
+# 20
+def long_to_ssize_t() -> ssize_t
+{
+    return long_val();
+}
+
+# 21
+def ssize_t_to_byte() -> byte
+{
+    return ssize_t_val();
+}
+
+# 22
+def ssize_t_to_short() -> short
+{
+    return ssize_t_val();
+}
+
+# 23
+def ssize_t_to_int() -> int
+{
+    return ssize_t_val();
+}
+
+# 24
+def ssize_t_to_long() -> long
+{
+    return ssize_t_val();
+}
+
+# 25
+def ubyte_val() -> ubyte
+{
+    return 0x42;
+}
+
+# 26
+def ushort_val() -> ushort
+{
+    return 0x4242;
+}
+
+# 27
+def uint_val() -> uint
+{
+    return 0x42424242;
+}
+
+# 28
+def ulong_val() -> ulong
+{
+    return 0x4242_4242_4242_4242;
+}
+
+# 29
+def size_t_val() -> size_t
+{
+    return 0x42424242;
+}
+
+# 30
+def ubyte_to_ushort() -> ushort
+{
+    return ubyte_val();
+}
+
+# 31
+def ubyte_to_uint() -> uint
+{
+    return ubyte_val();
+}
+
+# 32
+def ubyte_to_ulong() -> ulong
+{
+    return ubyte_val();
+}
+
+# 33
+def ubyte_to_size_t() -> size_t
+{
+    return ubyte_val();
+}
+
+# 34
+def ushort_to_ubyte() -> ubyte
+{
+    return ushort_val();
+}
+
+# 35
+def ushort_to_uint() -> uint
+{
+    return ushort_val();
+}
+
+# 36
+def ushort_to_ulong() -> ulong
+{
+    return ushort_val();
+}
+
+# 37
+def ushort_to_size_t() -> size_t
+{
+    return ushort_val();
+}
+
+# 38
+def uint_to_ubyte() -> ubyte
+{
+    return uint_val();
+}
+
+# 39
+def uint_to_ushort() -> ushort
+{
+    return uint_val();
+}
+
+# 40
+def uint_to_ulong() -> ulong
+{
+    return uint_val();
+}
+
+# 41
+def uint_to_size_t() -> size_t
+{
+    return uint_val();
+}
+
+# 42
+def ulong_to_ubyte() -> ubyte
+{
+    return ulong_val();
+}
+
+# 43
+def ulong_to_ushort() -> ushort
+{
+    return ulong_val();
+}
+
+# 44
+def ulong_to_uint() -> uint
+{
+    return ulong_val();
+}
+
+# 45
+def ulong_to_size_t() -> size_t
+{
+    return ulong_val();
+}
+
+# 46
+def size_t_to_ubyte() -> ubyte
+{
+    return size_t_val();
+}
+
+# 47
+def size_t_to_ushort() -> ushort
+{
+    return size_t_val();
+}
+
+# 48
+def size_t_to_int() -> int
+{
+    return size_t_val();
+}
+
+# 49
+def size_t_to_ulong() -> ulong
+{
+    return size_t_val();
+}
+
+# 50
+def main() -> int
+{
+    return int_val();
+}
+";
+    struct Expected
+    {
+        string name;
+        p_token_t token;
+    }
+    Expected[] expected = [
+        Expected("byte_val", TOKEN_byte),
+        Expected("short_val", TOKEN_short),
+        Expected("int_val", TOKEN_int),
+        Expected("long_val", TOKEN_long),
+        Expected("ssize_t_val", TOKEN_ssize_t),
+        Expected("byte_to_short", TOKEN_short),
+        Expected("byte_to_int", TOKEN_int),
+        Expected("byte_to_long", TOKEN_long),
+        Expected("byte_to_ssize_t", TOKEN_ssize_t),
+        Expected("short_to_byte", TOKEN_byte),
+        Expected("short_to_int", TOKEN_int),
+        Expected("short_to_long", TOKEN_long),
+        Expected("short_to_ssize_t", TOKEN_ssize_t),
+        Expected("int_to_byte", TOKEN_byte),
+        Expected("int_to_short", TOKEN_short),
+        Expected("int_to_long", TOKEN_long),
+        Expected("int_to_ssize_t", TOKEN_ssize_t),
+        Expected("long_to_byte", TOKEN_byte),
+        Expected("long_to_short", TOKEN_short),
+        Expected("long_to_int", TOKEN_int),
+        Expected("long_to_ssize_t", TOKEN_ssize_t),
+        Expected("ssize_t_to_byte", TOKEN_byte),
+        Expected("ssize_t_to_short", TOKEN_short),
+        Expected("ssize_t_to_int", TOKEN_int),
+        Expected("ssize_t_to_long", TOKEN_long),
+        Expected("ubyte_val", TOKEN_ubyte),
+        Expected("ushort_val", TOKEN_ushort),
+        Expected("uint_val", TOKEN_uint),
+        Expected("ulong_val", TOKEN_ulong),
+        Expected("size_t_val", TOKEN_size_t),
+        Expected("ubyte_to_ushort", TOKEN_ushort),
+        Expected("ubyte_to_uint", TOKEN_uint),
+        Expected("ubyte_to_ulong", TOKEN_ulong),
+        Expected("ubyte_to_size_t", TOKEN_size_t),
+        Expected("ushort_to_ubyte", TOKEN_ubyte),
+        Expected("ushort_to_uint", TOKEN_uint),
+        Expected("ushort_to_ulong", TOKEN_ulong),
+        Expected("ushort_to_size_t", TOKEN_size_t),
+        Expected("uint_to_ubyte", TOKEN_ubyte),
+        Expected("uint_to_ushort", TOKEN_ushort),
+        Expected("uint_to_ulong", TOKEN_ulong),
+        Expected("uint_to_size_t", TOKEN_size_t),
+        Expected("ulong_to_ubyte", TOKEN_ubyte),
+        Expected("ulong_to_ushort", TOKEN_ushort),
+        Expected("ulong_to_uint", TOKEN_uint),
+        Expected("ulong_to_size_t", TOKEN_size_t),
+        Expected("size_t_to_ubyte", TOKEN_ubyte),
+        Expected("size_t_to_ushort", TOKEN_ushort),
+        Expected("size_t_to_int", TOKEN_int),
+        Expected("size_t_to_ulong", TOKEN_ulong),
+        Expected("main", TOKEN_int),
+    ];
+    p_context_t context;
+    p_context_init(&context, input);
+    size_t result = p_parse(&context);
+    assert_eq(P_SUCCESS, result);
+    PModule * pmod = p_result(&context);
+    PModuleItems * pmis = pmod.pModuleItems;
+    PFunctionDefinition *[] pfds;
+    while (pmis !is null)
+    {
+        PModuleItem * pmi = pmis.pModuleItem;
+        if (pmi is null)
+        {
+            stderr.writeln("pmi is null!!!?");
+            assert(0);
+        }
+        PFunctionDefinition * pfd = pmi.pFunctionDefinition;
+        if (pfd !is null)
+        {
+            pfds = [pfd] ~ pfds;
+        }
+        pmis = pmis.pModuleItems;
+    }
+    assert_eq(51, pfds.length);
+    for (size_t i = 0; i < pfds.length; i++)
+    {
+        if ((expected[i].name != pfds[i].name.pvalue.s) ||
+            (expected[i].token != pfds[i].returntype.pType.pTypeBase.pToken1.token))
+        {
+            stderr.writeln("Index ", i, ": expected ", expected[i].name, "/", expected[i].token, ", got ", pfds[i].name.pvalue.s, "/", pfds[i].returntype.pType.pTypeBase.pToken1.token);
+        }
+    }
+}

spec/test_ast_ps.c

@@ -0,0 +1,55 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "a, ((b)), b";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert_eq(P_SUCCESS, p_parse(&context));
+    PStartS * start = p_result(&context);
+    assert(start->pItems1 != NULL);
+    assert(start->pItems != NULL);
+    PItemsS * items = start->pItems;
+    assert(items->pItem != NULL);
+    assert(items->pItem->pToken1 != NULL);
+    assert_eq(TOKEN_a, items->pItem->pToken1->token);
+    assert_eq(11, items->pItem->pToken1->pvalue);
+    assert(items->pItemsMore != NULL);
+    PItemsMoreS * itemsmore = items->pItemsMore;
+    assert(itemsmore->pItem != NULL);
+    assert(itemsmore->pItem->pItem != NULL);
+    assert(itemsmore->pItem->pItem->pItem != NULL);
+    assert(itemsmore->pItem->pItem->pItem->pToken1 != NULL);
+    assert_eq(TOKEN_b, itemsmore->pItem->pItem->pItem->pToken1->token);
+    assert_eq(22, itemsmore->pItem->pItem->pItem->pToken1->pvalue);
+    assert(itemsmore->pItemsMore != NULL);
+    itemsmore = itemsmore->pItemsMore;
+    assert(itemsmore->pItem != NULL);
+    assert(itemsmore->pItem->pToken1 != NULL);
+    assert_eq(TOKEN_b, itemsmore->pItem->pToken1->token);
+    assert_eq(22, itemsmore->pItem->pToken1->pvalue);
+    assert(itemsmore->pItemsMore == NULL);
+
+    input = "";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert_eq(P_SUCCESS, p_parse(&context));
+    start = p_result(&context);
+    assert(start->pItems == NULL);
+
+    input = "2 1";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert_eq(P_SUCCESS, p_parse(&context));
+    start = p_result(&context);
+    assert(start->pItems != NULL);
+    assert(start->pItems->pItem != NULL);
+    assert(start->pItems->pItem->pDual != NULL);
+    assert(start->pItems->pItem->pDual->pTwo1 != NULL);
+    assert(start->pItems->pItem->pDual->pOne2 != NULL);
+    assert(start->pItems->pItem->pDual->pTwo2 == NULL);
+    assert(start->pItems->pItem->pDual->pOne1 == NULL);
+
+    return 0;
+}

spec/test_ast_ps.d

@@ -0,0 +1,57 @@
+import testparser;
+import std.stdio;
+import testutils;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "a, ((b)), b";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert_eq(P_SUCCESS, p_parse(&context));
+    PStartS * start = p_result(&context);
+    assert(start.pItems1 !is null);
+    assert(start.pItems !is null);
+    PItemsS * items = start.pItems;
+    assert(items.pItem !is null);
+    assert(items.pItem.pToken1 !is null);
+    assert_eq(TOKEN_a, items.pItem.pToken1.token);
+    assert_eq(11, items.pItem.pToken1.pvalue);
+    assert(items.pItemsMore !is null);
+    PItemsMoreS * itemsmore = items.pItemsMore;
+    assert(itemsmore.pItem !is null);
+    assert(itemsmore.pItem.pItem !is null);
+    assert(itemsmore.pItem.pItem.pItem !is null);
+    assert(itemsmore.pItem.pItem.pItem.pToken1 !is null);
+    assert_eq(TOKEN_b, itemsmore.pItem.pItem.pItem.pToken1.token);
+    assert_eq(22, itemsmore.pItem.pItem.pItem.pToken1.pvalue);
+    assert(itemsmore.pItemsMore !is null);
+    itemsmore = itemsmore.pItemsMore;
+    assert(itemsmore.pItem !is null);
+    assert(itemsmore.pItem.pToken1 !is null);
+    assert_eq(TOKEN_b, itemsmore.pItem.pToken1.token);
+    assert_eq(22, itemsmore.pItem.pToken1.pvalue);
+    assert(itemsmore.pItemsMore is null);
+
+    input = "";
+    p_context_init(&context, input);
+    assert_eq(P_SUCCESS, p_parse(&context));
+    start = p_result(&context);
+    assert(start.pItems is null);
+
+    input = "2 1";
+    p_context_init(&context, input);
+    assert_eq(P_SUCCESS, p_parse(&context));
+    start = p_result(&context);
+    assert(start.pItems !is null);
+    assert(start.pItems.pItem !is null);
+    assert(start.pItems.pItem.pDual !is null);
+    assert(start.pItems.pItem.pDual.pTwo1 !is null);
+    assert(start.pItems.pItem.pDual.pOne2 !is null);
+    assert(start.pItems.pItem.pDual.pTwo2 is null);
+    assert(start.pItems.pItem.pDual.pOne1 is null);
+}

spec/test_ast_token_positions.c

@@ -0,0 +1,84 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "abbccc";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    Start * start = p_result(&context);
+
+    assert_eq(1, start->pT1->pToken->position.row);
+    assert_eq(1, start->pT1->pToken->position.col);
+    assert_eq(1, start->pT1->pToken->end_position.row);
+    assert_eq(1, start->pT1->pToken->end_position.col);
+    assert_eq(1, start->pT1->position.row);
+    assert_eq(1, start->pT1->position.col);
+    assert_eq(1, start->pT1->end_position.row);
+    assert_eq(1, start->pT1->end_position.col);
+
+    assert_eq(1, start->pT2->pToken->position.row);
+    assert_eq(2, start->pT2->pToken->position.col);
+    assert_eq(1, start->pT2->pToken->end_position.row);
+    assert_eq(3, start->pT2->pToken->end_position.col);
+    assert_eq(1, start->pT2->position.row);
+    assert_eq(2, start->pT2->position.col);
+    assert_eq(1, start->pT2->end_position.row);
+    assert_eq(3, start->pT2->end_position.col);
+
+    assert_eq(1, start->pT3->pToken->position.row);
+    assert_eq(4, start->pT3->pToken->position.col);
+    assert_eq(1, start->pT3->pToken->end_position.row);
+    assert_eq(6, start->pT3->pToken->end_position.col);
+    assert_eq(1, start->pT3->position.row);
+    assert_eq(4, start->pT3->position.col);
+    assert_eq(1, start->pT3->end_position.row);
+    assert_eq(6, start->pT3->end_position.col);
+
+    assert_eq(1, start->position.row);
+    assert_eq(1, start->position.col);
+    assert_eq(1, start->end_position.row);
+    assert_eq(6, start->end_position.col);
+
+    input = "\n\n  bb\nc\ncc\n\n     a";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+
+    assert_eq(3, start->pT1->pToken->position.row);
+    assert_eq(3, start->pT1->pToken->position.col);
+    assert_eq(3, start->pT1->pToken->end_position.row);
+    assert_eq(4, start->pT1->pToken->end_position.col);
+    assert_eq(3, start->pT1->position.row);
+    assert_eq(3, start->pT1->position.col);
+    assert_eq(3, start->pT1->end_position.row);
+    assert_eq(4, start->pT1->end_position.col);
+
+    assert_eq(4, start->pT2->pToken->position.row);
+    assert_eq(1, start->pT2->pToken->position.col);
+    assert_eq(5, start->pT2->pToken->end_position.row);
+    assert_eq(2, start->pT2->pToken->end_position.col);
+    assert_eq(4, start->pT2->position.row);
+    assert_eq(1, start->pT2->position.col);
+    assert_eq(5, start->pT2->end_position.row);
+    assert_eq(2, start->pT2->end_position.col);
+
+    assert_eq(7, start->pT3->pToken->position.row);
+    assert_eq(6, start->pT3->pToken->position.col);
+    assert_eq(7, start->pT3->pToken->end_position.row);
+    assert_eq(6, start->pT3->pToken->end_position.col);
+    assert_eq(7, start->pT3->position.row);
+    assert_eq(6, start->pT3->position.col);
+    assert_eq(7, start->pT3->end_position.row);
+    assert_eq(6, start->pT3->end_position.col);
+
+    assert_eq(3, start->position.row);
+    assert_eq(3, start->position.col);
+    assert_eq(7, start->end_position.row);
+    assert_eq(6, start->end_position.col);
+
+    return 0;
+}

spec/test_ast_token_positions.d

@@ -0,0 +1,86 @@
+import testparser;
+import std.stdio;
+import testutils;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "abbccc";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    Start * start = p_result(&context);
+
+    assert_eq(1, start.pT1.pToken.position.row);
+    assert_eq(1, start.pT1.pToken.position.col);
+    assert_eq(1, start.pT1.pToken.end_position.row);
+    assert_eq(1, start.pT1.pToken.end_position.col);
+    assert_eq(1, start.pT1.position.row);
+    assert_eq(1, start.pT1.position.col);
+    assert_eq(1, start.pT1.end_position.row);
+    assert_eq(1, start.pT1.end_position.col);
+
+    assert_eq(1, start.pT2.pToken.position.row);
+    assert_eq(2, start.pT2.pToken.position.col);
+    assert_eq(1, start.pT2.pToken.end_position.row);
+    assert_eq(3, start.pT2.pToken.end_position.col);
+    assert_eq(1, start.pT2.position.row);
+    assert_eq(2, start.pT2.position.col);
+    assert_eq(1, start.pT2.end_position.row);
+    assert_eq(3, start.pT2.end_position.col);
+
+    assert_eq(1, start.pT3.pToken.position.row);
+    assert_eq(4, start.pT3.pToken.position.col);
+    assert_eq(1, start.pT3.pToken.end_position.row);
+    assert_eq(6, start.pT3.pToken.end_position.col);
+    assert_eq(1, start.pT3.position.row);
+    assert_eq(4, start.pT3.position.col);
+    assert_eq(1, start.pT3.end_position.row);
+    assert_eq(6, start.pT3.end_position.col);
+
+    assert_eq(1, start.position.row);
+    assert_eq(1, start.position.col);
+    assert_eq(1, start.end_position.row);
+    assert_eq(6, start.end_position.col);
+
+    input = "\n\n  bb\nc\ncc\n\n     a";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+
+    assert_eq(3, start.pT1.pToken.position.row);
+    assert_eq(3, start.pT1.pToken.position.col);
+    assert_eq(3, start.pT1.pToken.end_position.row);
+    assert_eq(4, start.pT1.pToken.end_position.col);
+    assert_eq(3, start.pT1.position.row);
+    assert_eq(3, start.pT1.position.col);
+    assert_eq(3, start.pT1.end_position.row);
+    assert_eq(4, start.pT1.end_position.col);
+
+    assert_eq(4, start.pT2.pToken.position.row);
+    assert_eq(1, start.pT2.pToken.position.col);
+    assert_eq(5, start.pT2.pToken.end_position.row);
+    assert_eq(2, start.pT2.pToken.end_position.col);
+    assert_eq(4, start.pT2.position.row);
+    assert_eq(1, start.pT2.position.col);
+    assert_eq(5, start.pT2.end_position.row);
+    assert_eq(2, start.pT2.end_position.col);
+
+    assert_eq(7, start.pT3.pToken.position.row);
+    assert_eq(6, start.pT3.pToken.position.col);
+    assert_eq(7, start.pT3.pToken.end_position.row);
+    assert_eq(6, start.pT3.pToken.end_position.col);
+    assert_eq(7, start.pT3.position.row);
+    assert_eq(6, start.pT3.position.col);
+    assert_eq(7, start.pT3.end_position.row);
+    assert_eq(6, start.pT3.end_position.col);
+
+    assert_eq(3, start.position.row);
+    assert_eq(3, start.position.col);
+    assert_eq(7, start.end_position.row);
+    assert_eq(6, start.end_position.col);
+}

spec/test_error_positions.c

@@ -12,28 +12,28 @@ int main()
     input = "a\n123\na  a";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_UNEXPECTED_TOKEN);
-    assert(p_position(&context).row == 2);
-    assert(p_position(&context).col == 3);
+    assert(p_position(&context).row == 3);
+    assert(p_position(&context).col == 4);
     assert(p_token(&context) == TOKEN_a);
 
     input = "12";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_UNEXPECTED_TOKEN);
-    assert(p_position(&context).row == 0);
-    assert(p_position(&context).col == 0);
+    assert(p_position(&context).row == 1);
+    assert(p_position(&context).col == 1);
     assert(p_token(&context) == TOKEN_num);
 
     input = "a 12\n\nab";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_UNEXPECTED_INPUT);
-    assert(p_position(&context).row == 2);
-    assert(p_position(&context).col == 1);
+    assert(p_position(&context).row == 3);
+    assert(p_position(&context).col == 2);
 
     input = "a 12\n\na\n\n77\na   \xAA";
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_DECODE_ERROR);
-    assert(p_position(&context).row == 5);
-    assert(p_position(&context).col == 4);
+    assert(p_position(&context).row == 6);
+    assert(p_position(&context).col == 5);
 
     assert(strcmp(p_token_names[TOKEN_a], "a") == 0);
     assert(strcmp(p_token_names[TOKEN_num], "num") == 0);

spec/test_error_positions.d

@@ -16,24 +16,24 @@ unittest
     input = "a\n123\na  a";
     p_context_init(&context, input);
     assert(p_parse(&context) == P_UNEXPECTED_TOKEN);
-    assert(p_position(&context) == p_position_t(2, 3));
+    assert(p_position(&context) == p_position_t(3, 4));
     assert(p_token(&context) == TOKEN_a);
 
     input = "12";
     p_context_init(&context, input);
     assert(p_parse(&context) == P_UNEXPECTED_TOKEN);
-    assert(p_position(&context) == p_position_t(0, 0));
+    assert(p_position(&context) == p_position_t(1, 1));
     assert(p_token(&context) == TOKEN_num);
 
     input = "a 12\n\nab";
     p_context_init(&context, input);
     assert(p_parse(&context) == P_UNEXPECTED_INPUT);
-    assert(p_position(&context) == p_position_t(2, 1));
+    assert(p_position(&context) == p_position_t(3, 2));
 
     input = "a 12\n\na\n\n77\na   \xAA";
     p_context_init(&context, input);
     assert(p_parse(&context) == P_DECODE_ERROR);
-    assert(p_position(&context) == p_position_t(5, 4));
+    assert(p_position(&context) == p_position_t(6, 5));
 
     assert(p_token_names[TOKEN_a] == "a");
     assert(p_token_names[TOKEN_num] == "num");

spec/test_field_aliases.c

@@ -0,0 +1,13 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "foo1\nbar2";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    return 0;
+}

spec/test_field_aliases.d

@@ -0,0 +1,15 @@
+import testparser;
+import std.stdio;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "foo1\nbar2";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+}

spec/test_lexer.c

@@ -41,50 +41,68 @@ int main()
     p_context_t context;
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info.position.row == 0u);
-    assert(token_info.position.col == 0u);
+    assert(token_info.position.row == 1u);
+    assert(token_info.position.col == 1u);
+    assert(token_info.end_position.row == 1u);
+    assert(token_info.end_position.col == 1u);
     assert(token_info.length == 1u);
     assert(token_info.token == TOKEN_int);
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info.position.row == 0u);
-    assert(token_info.position.col == 2u);
+    assert(token_info.position.row == 1u);
+    assert(token_info.position.col == 3u);
+    assert(token_info.end_position.row == 1u);
+    assert(token_info.end_position.col == 3u);
     assert(token_info.length == 1u);
     assert(token_info.token == TOKEN_plus);
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info.position.row == 0u);
-    assert(token_info.position.col == 4u);
+    assert(token_info.position.row == 1u);
+    assert(token_info.position.col == 5u);
+    assert(token_info.end_position.row == 1u);
+    assert(token_info.end_position.col == 5u);
     assert(token_info.length == 1u);
     assert(token_info.token == TOKEN_int);
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info.position.row == 0u);
-    assert(token_info.position.col == 6u);
+    assert(token_info.position.row == 1u);
+    assert(token_info.position.col == 7u);
+    assert(token_info.end_position.row == 1u);
+    assert(token_info.end_position.col == 7u);
     assert(token_info.length == 1u);
     assert(token_info.token == TOKEN_times);
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info.position.row == 1u);
-    assert(token_info.position.col == 0u);
+    assert(token_info.position.row == 2u);
+    assert(token_info.position.col == 1u);
+    assert(token_info.end_position.row == 2u);
+    assert(token_info.end_position.col == 3u);
     assert(token_info.length == 3u);
     assert(token_info.token == TOKEN_int);
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info.position.row == 1u);
-    assert(token_info.position.col == 4u);
+    assert(token_info.position.row == 2u);
+    assert(token_info.position.col == 5u);
+    assert(token_info.end_position.row == 2u);
+    assert(token_info.end_position.col == 5u);
     assert(token_info.length == 1u);
     assert(token_info.token == TOKEN_plus);
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info.position.row == 1u);
-    assert(token_info.position.col == 6u);
+    assert(token_info.position.row == 2u);
+    assert(token_info.position.col == 7u);
+    assert(token_info.end_position.row == 2u);
+    assert(token_info.end_position.col == 9u);
     assert(token_info.length == 3u);
     assert(token_info.token == TOKEN_int);
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info.position.row == 1u);
-    assert(token_info.position.col == 9u);
+    assert(token_info.position.row == 2u);
+    assert(token_info.position.col == 10u);
+    assert(token_info.end_position.row == 2u);
+    assert(token_info.end_position.col == 10u);
     assert(token_info.length == 0u);
     assert(token_info.token == TOKEN___EOF);
 
     p_context_init(&context, (uint8_t const *)"", 0u);
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info.position.row == 0u);
-    assert(token_info.position.col == 0u);
+    assert(token_info.position.row == 1u);
+    assert(token_info.position.col == 1u);
+    assert(token_info.end_position.row == 1u);
+    assert(token_info.end_position.col == 1u);
     assert(token_info.length == 0u);
     assert(token_info.token == TOKEN___EOF);
 

spec/test_lexer.d

@@ -47,23 +47,23 @@ unittest
     p_context_t context;
     p_context_init(&context, input);
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info == p_token_info_t(p_position_t(0, 0), 1, TOKEN_int));
+    assert(token_info == p_token_info_t(p_position_t(1, 1), p_position_t(1, 1), 1, TOKEN_int));
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info == p_token_info_t(p_position_t(0, 2), 1, TOKEN_plus));
+    assert(token_info == p_token_info_t(p_position_t(1, 3), p_position_t(1, 3), 1, TOKEN_plus));
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info == p_token_info_t(p_position_t(0, 4), 1, TOKEN_int));
+    assert(token_info == p_token_info_t(p_position_t(1, 5), p_position_t(1, 5), 1, TOKEN_int));
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info == p_token_info_t(p_position_t(0, 6), 1, TOKEN_times));
+    assert(token_info == p_token_info_t(p_position_t(1, 7), p_position_t(1, 7), 1, TOKEN_times));
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info == p_token_info_t(p_position_t(1, 0), 3, TOKEN_int));
+    assert(token_info == p_token_info_t(p_position_t(2, 1), p_position_t(2, 3), 3, TOKEN_int));
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info == p_token_info_t(p_position_t(1, 4), 1, TOKEN_plus));
+    assert(token_info == p_token_info_t(p_position_t(2, 5), p_position_t(2, 5), 1, TOKEN_plus));
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info == p_token_info_t(p_position_t(1, 6), 3, TOKEN_int));
+    assert(token_info == p_token_info_t(p_position_t(2, 7), p_position_t(2, 9), 3, TOKEN_int));
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info == p_token_info_t(p_position_t(1, 9), 0, TOKEN___EOF));
+    assert(token_info == p_token_info_t(p_position_t(2, 10), p_position_t(2, 10), 0, TOKEN___EOF));
 
     p_context_init(&context, "");
     assert(p_lex(&context, &token_info) == P_SUCCESS);
-    assert(token_info == p_token_info_t(p_position_t(0, 0), 0, TOKEN___EOF));
+    assert(token_info == p_token_info_t(p_position_t(1, 1), p_position_t(1, 1), 0, TOKEN___EOF));
 }

spec/test_lexer_multiple_modes.c

@@ -0,0 +1,20 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+
+int main()
+{
+    char const * input = "abc.def";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    printf("pass1\n");
+
+    input = "abc .  abc";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    printf("pass2\n");
+
+    return 0;
+}

spec/test_lexer_multiple_modes.d

@@ -0,0 +1,21 @@
+import testparser;
+import std.stdio;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = `abc.def`;
+    p_context_t context;
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    writeln("pass1");
+
+    input = `abc .  abc`;
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    writeln("pass2");
+}

spec/test_named_optional_rule_component_ast.c

@@ -0,0 +1,45 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "b";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    Start * start = p_result(&context);
+    assert(start->a == NULL);
+    assert(start->pToken2 != NULL);
+    assert_eq(TOKEN_b, start->pToken2->token);
+    assert(start->pR3 == NULL);
+    assert(start->pR == NULL);
+    assert(start->r == NULL);
+
+    input = "abcd";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+    assert(start->a != NULL);
+    assert_eq(TOKEN_a, start->pToken1->token);
+    assert(start->pToken2 != NULL);
+    assert(start->pR3 != NULL);
+    assert(start->pR != NULL);
+    assert(start->r != NULL);
+    assert(start->pR == start->pR3);
+    assert(start->pR == start->r);
+    assert_eq(TOKEN_c, start->pR->pToken1->token);
+
+    input = "bdc";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+    assert(start->a == NULL);
+    assert(start->pToken2 != NULL);
+    assert(start->r != NULL);
+    assert_eq(TOKEN_d, start->pR->pToken1->token);
+
+    return 0;
+}
+

spec/test_named_optional_rule_component_ast.d

@@ -0,0 +1,46 @@
+import testparser;
+import std.stdio;
+import testutils;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "b";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    Start * start = p_result(&context);
+    assert(start.pToken1 is null);
+    assert(start.pToken2 !is null);
+    assert_eq(TOKEN_b, start.pToken2.token);
+    assert(start.pR3 is null);
+    assert(start.pR is null);
+    assert(start.r is null);
+
+    input = "abcd";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+    assert(start.pToken1 != null);
+    assert_eq(TOKEN_a, start.pToken1.token);
+    assert(start.pToken2 != null);
+    assert(start.pR3 != null);
+    assert(start.pR != null);
+    assert(start.r != null);
+    assert(start.pR == start.pR3);
+    assert(start.pR == start.r);
+    assert_eq(TOKEN_c, start.pR.pToken1.token);
+
+    input = "bdc";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+    assert(start.pToken1 is null);
+    assert(start.pToken2 !is null);
+    assert(start.pR !is null);
+    assert_eq(TOKEN_d, start.pR.pToken1.token);
+}

spec/test_optional_rule_component.c

@@ -0,0 +1,22 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+
+int main()
+{
+    char const * input = "b";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+
+    input = "abcd";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+
+    input = "abdc";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+
+    return 0;
+}
+

spec/test_optional_rule_component.d

@@ -0,0 +1,23 @@
+import testparser;
+import std.stdio;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "b";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+
+    input = "abcd";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+
+    input = "abdc";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+}

spec/test_optional_rule_component_ast.c

@@ -0,0 +1,42 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "b";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    Start * start = p_result(&context);
+    assert(start->pToken1 == NULL);
+    assert(start->pToken2 != NULL);
+    assert_eq(TOKEN_b, start->pToken2->token);
+    assert(start->pR3 == NULL);
+    assert(start->pR == NULL);
+
+    input = "abcd";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+    assert(start->pToken1 != NULL);
+    assert_eq(TOKEN_a, start->pToken1->token);
+    assert(start->pToken2 != NULL);
+    assert(start->pR3 != NULL);
+    assert(start->pR != NULL);
+    assert(start->pR == start->pR3);
+    assert_eq(TOKEN_c, start->pR->pToken1->token);
+
+    input = "bdc";
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+    assert(start->pToken1 == NULL);
+    assert(start->pToken2 != NULL);
+    assert(start->pR != NULL);
+    assert_eq(TOKEN_d, start->pR->pToken1->token);
+
+    return 0;
+}
+

spec/test_optional_rule_component_ast.d

@@ -0,0 +1,43 @@
+import testparser;
+import std.stdio;
+import testutils;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "b";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    Start * start = p_result(&context);
+    assert(start.pToken1 is null);
+    assert(start.pToken2 !is null);
+    assert_eq(TOKEN_b, start.pToken2.token);
+    assert(start.pR3 is null);
+    assert(start.pR is null);
+
+    input = "abcd";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+    assert(start.pToken1 != null);
+    assert_eq(TOKEN_a, start.pToken1.token);
+    assert(start.pToken2 != null);
+    assert(start.pR3 != null);
+    assert(start.pR != null);
+    assert(start.pR == start.pR3);
+    assert_eq(TOKEN_c, start.pR.pToken1.token);
+
+    input = "bdc";
+    p_context_init(&context, input);
+    assert(p_parse(&context) == P_SUCCESS);
+    start = p_result(&context);
+    assert(start.pToken1 is null);
+    assert(start.pToken2 !is null);
+    assert(start.pR !is null);
+    assert_eq(TOKEN_d, start.pR.pToken1.token);
+}

spec/test_parser_rule_from_multiple_states.c

@@ -8,8 +8,8 @@ int main()
     p_context_t context;
     p_context_init(&context, (uint8_t const *)input, strlen(input));
     assert(p_parse(&context) == P_UNEXPECTED_TOKEN);
-    assert(p_position(&context).row == 0);
-    assert(p_position(&context).col == 1);
+    assert(p_position(&context).row == 1);
+    assert(p_position(&context).col == 2);
     assert(context.token == TOKEN___EOF);
 
     input = "a b";

spec/test_parser_rule_from_multiple_states.d

@@ -12,7 +12,7 @@ unittest
     p_context_t context;
     p_context_init(&context, input);
     assert(p_parse(&context) == P_UNEXPECTED_TOKEN);
-    assert(p_position(&context) == p_position_t(0, 1));
+    assert(p_position(&context) == p_position_t(1, 2));
     assert(context.token == TOKEN___EOF);
 
     input = "a b";

spec/test_start_rule.c

@@ -0,0 +1,9 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    return 0;
+}

spec/test_start_rule.d

@@ -0,0 +1,8 @@
+import testparser;
+import std.stdio;
+import testutils;
+
+int main()
+{
+    return 0;
+}

spec/test_start_rule_ast.c

@@ -0,0 +1,17 @@
+#include "testparser.h"
+#include <assert.h>
+#include <string.h>
+#include "testutils.h"
+
+int main()
+{
+    char const * input = "hi";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert_eq(P_SUCCESS, p_parse(&context));
+    Top * top = p_result(&context);
+    assert(top->pToken != NULL);
+    assert_eq(TOKEN_hi, top->pToken->token);
+
+    return 0;
+}

spec/test_start_rule_ast.d

@@ -0,0 +1,19 @@
+import testparser;
+import std.stdio;
+import testutils;
+
+int main()
+{
+    return 0;
+}
+
+unittest
+{
+    string input = "hi";
+    p_context_t context;
+    p_context_init(&context, input);
+    assert_eq(P_SUCCESS, p_parse(&context));
+    Top * top = p_result(&context);
+    assert(top.pToken !is null);
+    assert_eq(TOKEN_hi, top.pToken.token);
+}