Allow field aliases for non-AST mode

lib/propane/generator.rb

@@ -276,6 +276,19 @@ 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|
           if @grammar.ast

spec/propane_spec.rb

@@ -237,7 +237,7 @@ EOF
     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 disabled" do
+  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;
@@ -1157,7 +1157,7 @@ EOF
         expect(results.status).to eq 0
       end
 
-      it "allows specifying field aliases" do
+      it "allows specifying field aliases in AST mode" do
         write_grammar <<EOF
 ast;
 
@@ -1171,11 +1171,55 @@ T -> b;
 T -> c;
 EOF
         run_propane(language: language)
-        compile("spec/test_field_aliases.#{language}", 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
     end
   end
 end

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);
+}