lib/antelope/generator/output.rb in antelope-0.1.7 vs lib/antelope/generator/output.rb in antelope-0.1.8

@@ -1,23 +1,40 @@
 # encoding: utf-8
 
 require "pp"
 
 module Antelope
-  class Generator
+  module Generator
 
     # Generates an output file, mainly for debugging.  Included always
     # as a generator for a grammar.
-    class Output < Generator
+    class Output < Base
 
+      register_as "output"
+
       # Defines singleton method for every mod that the grammar passed
       # to the generator.
       #
       # @see Generator#initialize
       def initialize(*)
         super
         mods.each do |k, v|
           define_singleton_method (k) { v }
+        end
+      end
+
+      def unused_symbols
+        @_unused_symbols ||= begin
+          used = grammar.all_productions.map(&:items).flatten.uniq
+          all  = grammar.symbols.map do |s|
+            if Symbol === s
+              grammar.find_token(s)
+            else
+              s
+            end
+          end
+
+          all - used - [grammar.find_token(:"$start")]
         end
       end
 
       # Actually performs the generation.  Uses the template in
       # output.erb, and generates the file `<file>.output`.