Token should build its own NFA

lib/imbecile/grammar.rb

@@ -46,13 +46,9 @@ module Imbecile
       end
 
       # Build NFA from each token expression.
-      i = 0
       nfas = @tokens.map do |token|
-        regex = Regex.new(token.pattern)
-        regex.nfa.end_state.accepts = "#{i}:#{token.name}"
-        puts regex.nfa
-        i += 1
-        regex.nfa
+        puts token.nfa
+        token.nfa
       end
       dfa = Regex::DFA.new(nfas)
       puts dfa

lib/imbecile/grammar/token.rb

@@ -15,10 +15,21 @@ module Imbecile
       #   Token ID.
       attr_reader :id
 
+      # @return [Regex::NFA]
+      #   Regex NFA for matching the token.
+      attr_reader :nfa
+
       def initialize(name, pattern, id)
         @name = name
         @pattern = pattern
         @id = id
+        regex = Regex.new(pattern)
+        regex.nfa.end_state.accepts = self
+        @nfa = regex.nfa
+      end
+
+      def to_s
+        @name
       end
 
     end

lib/imbecile/regex/dfa.rb

@@ -38,7 +38,7 @@ module Imbecile
         nfa_state_set.each do |nfa_state|
           if nfa_state.accepts
             if state.accepts
-              if nfa_state.accepts.to_i < state.accepts.to_i
+              if nfa_state.accepts.id < state.accepts.id
                 state.accepts = nfa_state.accepts
               end
             else