From c42c3576a51ed0c6565145b4a0388a02ea414973 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Sun, 5 Jun 2022 15:16:41 -0400
Subject: [PATCH] Remove RuleSet creation from Grammar

---
 lib/propane/generator.rb | 33 +++++++++++++++++----------------
 lib/propane/grammar.rb   |  8 +++-----
 lib/propane/parser.rb    |  4 ++--
 lib/propane/rule_set.rb  |  7 ++-----
 4 files changed, 24 insertions(+), 28 deletions(-)

diff --git a/lib/propane/generator.rb b/lib/propane/generator.rb
index 0a7c5f2..11ab8c9 100644
--- a/lib/propane/generator.rb
+++ b/lib/propane/generator.rb
@@ -8,8 +8,6 @@ class Propane
       @log_file = log_file
       @classname = @grammar.classname || File.basename(output_file).sub(%r{[^a-zA-Z0-9].*}, "").capitalize
       process_grammar!
-      @lexer = Lexer.new(@grammar.tokens, @grammar.drop_tokens)
-      @parser = Parser.new(@grammar.rule_sets)
     end
 
     def generate
@@ -30,27 +28,30 @@ class Propane
         end
         tokens_by_name[token.name] = token
       end
-      @grammar.rule_sets.each do |rule_name, rule_set|
-        if tokens_by_name.include?(rule_name)
-          raise Error.new("Rule name collides with token name #{rule_name.inspect}")
+      rule_sets = {}
+      @grammar.rules.each do |rule|
+        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_sets[rule.name] << rule
       end
-      unless @grammar.rule_sets["Start"]
+      unless rule_sets["Start"]
         raise Error.new("Start rule not found")
       end
-      @grammar.rule_sets.each do |rule_name, rule_set|
-        rule_set.rules.each do |rule|
-          rule.components.map! do |component|
-            if tokens_by_name[component]
-              tokens_by_name[component]
-            elsif @grammar.rule_sets[component]
-              @grammar.rule_sets[component]
-            else
-              raise Error.new("Symbol #{component} not found")
-            end
+      @grammar.rules.each do |rule|
+        rule.components.map! do |component|
+          if tokens_by_name[component]
+            tokens_by_name[component]
+          elsif rule_sets[component]
+            rule_sets[component]
+          else
+            raise Error.new("Symbol #{component} not found")
           end
         end
       end
+      @lexer = Lexer.new(@grammar.tokens, @grammar.drop_tokens)
+      @parser = Parser.new(rule_sets["Start"])
     end
 
   end
diff --git a/lib/propane/grammar.rb b/lib/propane/grammar.rb
index c0572a8..105f5df 100644
--- a/lib/propane/grammar.rb
+++ b/lib/propane/grammar.rb
@@ -5,13 +5,13 @@ class Propane
     attr_reader :classname
     attr_reader :drop_tokens
     attr_reader :modulename
-    attr_reader :rule_sets
+    attr_reader :rules
     attr_reader :tokens
 
     def initialize(input)
       @tokens = []
       @drop_tokens = []
-      @rule_sets = {}
+      @rules = []
       input = input.gsub("\r\n", "\n")
       parse_grammar(input)
     end
@@ -44,9 +44,7 @@ class Propane
         elsif sliced = input.slice!(/\A(\S+)\s*:\s*\[(.*?)\] <<\n(.*?)^>>\n/m)
           rule_name, components, code = $1, $2, $3
           components = components.strip.split(/\s+/)
-          @rule_sets[rule_name] ||= RuleSet.new(rule_name, @rule_sets.size)
-          rule = Rule.new(rule_name, components, code, line_number)
-          @rule_sets[rule_name].add_rule(rule)
+          @rules << Rule.new(rule_name, components, code, line_number)
         else
           if input.size > 25
             input = input.slice(0..20) + "..."
diff --git a/lib/propane/parser.rb b/lib/propane/parser.rb
index be5c70c..172d936 100644
--- a/lib/propane/parser.rb
+++ b/lib/propane/parser.rb
@@ -2,11 +2,11 @@ class Propane
 
   class Parser
 
-    def initialize(rule_sets)
+    def initialize(start_rule_set)
       @token_eof = Token.new(name: "$", id: TOKEN_EOF)
       @item_sets = []
       @item_sets_set = {}
-      start_items = rule_sets["Start"].rules.map do |rule|
+      start_items = start_rule_set.rules.map do |rule|
         rule.components << @token_eof
         Item.new(rule, 0)
       end
diff --git a/lib/propane/rule_set.rb b/lib/propane/rule_set.rb
index 3c4637c..6013ba1 100644
--- a/lib/propane/rule_set.rb
+++ b/lib/propane/rule_set.rb
@@ -2,19 +2,16 @@ class Propane
 
   class RuleSet
 
-    attr_reader :id
-
     attr_reader :name
 
     attr_reader :rules
 
-    def initialize(name, id)
+    def initialize(name)
       @name = name
-      @id = id
       @rules = []
     end
 
-    def add_rule(rule)
+    def <<(rule)
       @rules << rule
     end