Add RuleSet#id to use when reducing

Parser will know what state to go to after reducing a Rule based on the
RuleSet ID.
Start on Parser class.

lib/propane/generator.rb

@@ -33,7 +33,9 @@ class Propane
         if tokens_by_name.include?(rule.name)
           raise Error.new("Rule name collides with token name #{rule.name.inspect}")
         end
-        rule_sets[rule.name] ||= RuleSet.new(rule.name)
+        @_rule_set_id ||= @grammar.tokens.size
+        rule_sets[rule.name] ||= RuleSet.new(rule.name, @_rule_set_id)
+        @_rule_set_id += 1
         rule.rule_set = rule_sets[rule.name]
         rule_sets[rule.name] << rule
       end

lib/propane/parser.rb

@@ -60,22 +60,43 @@ class Propane
     def build_tables
       shift_table = []
       state_table = []
+      reduce_table = []
       @item_sets.each do |item_set|
         shift_entries = item_set.following_symbols.select do |following_symbol|
           following_symbol.is_a?(Token)
         end.map do |following_symbol|
+          state_id =
+            if following_symbol == @eof_token
+              0
+            else
+              item_set.following_item_set[following_symbol].id
+            end
           {
             token_id: following_symbol.id,
-            state_id: item_set.following_item_set[following_symbol].id,
+            state_id: state_id,
           }
         end
+        reduce_entries =
+          case ra = item_set.reduce_actions
+          when Rule
+            [{token_id: TOKEN_NONE, rule_id: ra.id, rule_set_id: ra.rule_set.id}]
+          when Hash
+            ra.map do |token, rule|
+              {token_id: token.id, rule_id: rule.id, rule_set_id: rule.rule_set.id}
+            end
+          else
+            []
+          end
         state_table << {
           shift_index: shift_table.size,
           n_shifts: shift_entries.size,
+          reduce_index: reduce_table.size,
+          n_reduces: reduce_entries.size,
         }
         shift_table += shift_entries
+        reduce_table += reduce_entries
       end
-      [state_table, shift_table]
+      [state_table, shift_table, reduce_table]
     end
 
     private

lib/propane/rule_set.rb

@@ -2,6 +2,10 @@ class Propane
 
   class RuleSet
 
+    # @return [Integer]
+    #   ID of the RuleSet.
+    attr_accessor :id
+
     # @return [String]
     #   Name of the RuleSet.
     attr_reader :name
@@ -18,7 +22,10 @@ class Propane
     #
     # @param name [String]
     #   Name of the RuleSet.
-    def initialize(name)
+    # @param id [Integer]
+    #   ID of the RuleSet.
+    def initialize(name, id)
+      @id = id
       @name = name
       @rules = []
       @could_be_empty = false