Package org.antlr.v4.runtime.atn
Class LexerATNSimulator.SimState
- java.lang.Object
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- org.antlr.v4.runtime.atn.LexerATNSimulator.SimState
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- Enclosing class:
- LexerATNSimulator
protected static class LexerATNSimulator.SimState extends Object
When we hit an accept state in either the DFA or the ATN, we have to notify the character stream to start buffering characters viaIntStream.mark()
and record the current state. The current sim state includes the current index into the input, the current line, and current character position in that line. Note that the Lexer is tracking the starting line and characterization of the token. These variables track the "state" of the simulator when it hits an accept state.We track these variables separately for the DFA and ATN simulation because the DFA simulation often has to fail over to the ATN simulation. If the ATN simulation fails, we need the DFA to fall back to its previously accepted state, if any. If the ATN succeeds, then the ATN does the accept and the DFA simulator that invoked it can simply return the predicted token type.
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Constructor Summary
Constructors Modifier Constructor Description protected
SimState()
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Field Detail
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index
protected int index
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line
protected int line
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charPos
protected int charPos
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dfaState
protected DFAState dfaState
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