Package org.antlr.tool
Class FASerializer
java.lang.Object
org.antlr.tool.FASerializer
An aspect of FA (finite automata) that knows how to dump them to serialized
strings.
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Field Summary
FieldsModifier and TypeFieldDescriptionprotected Grammar
To prevent infinite recursion when walking state machines, record which states we've visited.protected int
Each state we walk will get a new state number for serialization purposes.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
ConstructorsConstructorDescriptionFASerializer
(Grammar grammar) This aspect is associated with a grammar; used to get token names -
Method Summary
Modifier and TypeMethodDescriptionprivate String
getStateString
(int n, State s) Return a string representation of a state machine.protected void
In stateNumberTranslator, get a map from State to new, normalized state number.protected void
walkSerializingFA
(List<String> lines, State s)
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Field Details
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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 stateCounterEach state we walk will get a new state number for serialization purposes. This is the variable that tracks state numbers. -
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
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Constructor Details
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FASerializer
This aspect is associated with a grammar; used to get token names
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Method Details
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serialize
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serialize
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
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
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getStateString
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