Package org.antlr.tool

Class FASerializer

  • public class FASerializer
extends java.lang.Object
    An aspect of FA (finite automata) that knows how to dump them to serialized strings.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected Grammar grammar  
      protected java.util.Set<State> markedStates
      To prevent infinite recursion when walking state machines, record which states we've visited.
      protected int stateCounter
      Each state we walk will get a new state number for serialization purposes.
      protected java.util.Map<State,​java.lang.Integer> stateNumberTranslator
      Rather than add a new instance variable to NFA and DFA just for serializing machines, map old state numbers to new state numbers by a State object → Integer new state number HashMap.

    • Constructor Summary

      Constructors 
      Constructor Description
      FASerializer​(Grammar grammar)
      This aspect is associated with a grammar; used to get token names

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String serialize​(State s)  
      java.lang.String serialize​(State s, boolean renumber)
      Return a string representation of a state machine.
      protected void walkFANormalizingStateNumbers​(State s)
      In stateNumberTranslator, get a map from State to new, normalized state number.
      protected void walkSerializingFA​(java.util.List<java.lang.String> lines, State s)  

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • markedStates

        protected java.util.Set<State> markedStates
        To prevent infinite recursion when walking state machines, record which states we've visited. Make a new set every time you start walking in case you reuse this object. Multiple threads will trash this shared variable. Use a different FASerializer per thread.

      • stateCounter

        protected int stateCounter
        Each state we walk will get a new state number for serialization purposes. This is the variable that tracks state numbers.

      • stateNumberTranslator

        protected java.util.Map<State,​java.lang.Integer> stateNumberTranslator
        Rather than add a new instance variable to NFA and DFA just for serializing machines, map old state numbers to new state numbers by a State object → Integer new state number HashMap.

      • grammar

        protected Grammar grammar

    • Constructor Detail

      • FASerializer

        public FASerializer​(Grammar grammar)
        This aspect is associated with a grammar; used to get token names

    • Method Detail

      • serialize

        public java.lang.String serialize​(State s)

      • serialize

        public java.lang.String serialize​(State s,
                                  boolean renumber)
        Return a string representation of a state machine. Two identical NFAs or DFAs will have identical serialized representations. The state numbers inside the state are not used; instead, a new number is computed and because the serialization will walk the two machines using the same specific algorithm, then the state numbers will be identical. Accept states are distinguished from regular states.

      • walkFANormalizingStateNumbers

        protected void walkFANormalizingStateNumbers​(State s)
        In stateNumberTranslator, get a map from State to new, normalized state number. Used by walkSerializingFA to make sure any two identical state machines will serialize the same way.

      • walkSerializingFA

        protected void walkSerializingFA​(java.util.List<java.lang.String> lines,
                                 State s)