ANTLR 4 Runtime (Optimized) 4.9.0 · org.antlr.v4.runtime.atn.ATN

Field Summary

Modifier and Type	Field and Description
private final ConcurrentMap<PredictionContext, PredictionContext>	contextCache
public DFA[]	decisionToDFA
public final List<DecisionState>	decisionToState Each subrule/rule is a decision point and we must track them so we can go back later and build DFA predictors for them.
public final ATNType	grammarType The type of the ATN.
private boolean	hasUnicodeSMPTransitions
public static final int	INVALID_ALT_NUMBER
public LexerAction[]	lexerActions For lexer ATNs, this is an array of `LexerAction` objects which may be referenced by action transitions in the ATN.
protected final ConcurrentMap<Integer, Integer>	LL1Table
public final int	maxTokenType The maximum value for any symbol recognized by a transition in the ATN.
public final Map<String, TokensStartState>	modeNameToStartState
public DFA[]	modeToDFA
public final List<TokensStartState>	modeToStartState
public RuleStartState[]	ruleToStartState Maps from rule index to starting state number.
public RuleStopState[]	ruleToStopState Maps from rule index to stop state number.
public int[]	ruleToTokenType For lexer ATNs, this maps the rule index to the resulting token type.
public final List<ATNState>	states

Constructor Summary

Access	Constructor and Description
public	ATN(ATNType grammarType, int maxTokenType) Used for runtime deserialization of ATNs from strings

Method Summary

Modifier and Type	Method and Description
public void	addState(ATNState state)
public final void	clearDFA()
public int	defineDecisionState(DecisionState s)
public void	defineMode(String name, TokensStartState s)
public PredictionContext	getCachedContext(PredictionContext context)
public int	getContextCacheSize()
public DecisionState	getDecisionState(int decision)
public final DFA[]	getDecisionToDFA()
public IntervalSet	Returns: The set of potentially valid input symbols which could follow the specified state in the specified context. getExpectedTokens(int the ATN state number stateNumber, RuleContext the full parse context context) Computes the set of input symbols which could follow ATN state number `stateNumber` in the specified full `context`.</quote>
public int	getNumberOfDecisions()
public boolean	hasUnicodeSMPTransitions()
public IntervalSet	nextTokens(ATNState s, PredictionContext ctx) Compute the set of valid tokens that can occur starting in state `s`.
public IntervalSet	nextTokens(ATNState s) Compute the set of valid tokens that can occur starting in `s` and staying in same rule.
public void	removeState(ATNState state)
public void	setHasUnicodeSMPTransitions(boolean value)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

contextCache	back to summary
private final ConcurrentMap<PredictionContext, PredictionContext> contextCache

decisionToDFA	back to summary
public DFA[] decisionToDFA Annotations @NotNull

decisionToState	back to summary
public final List<DecisionState> decisionToState Each subrule/rule is a decision point and we must track them so we can go back later and build DFA predictors for them. This includes all the rules, subrules, optional blocks, ()+, ()* etc... Annotations @NotNull

grammarType	back to summary
public final ATNType grammarType The type of the ATN.

hasUnicodeSMPTransitions	back to summary
private boolean hasUnicodeSMPTransitions

INVALID_ALT_NUMBER	back to summary
public static final int INVALID_ALT_NUMBER

lexerActions	back to summary
public LexerAction[] lexerActions For lexer ATNs, this is an array of `LexerAction` objects which may be referenced by action transitions in the ATN.

LL1Table	back to summary
protected final ConcurrentMap<Integer, Integer> LL1Table

maxTokenType	back to summary
public final int maxTokenType The maximum value for any symbol recognized by a transition in the ATN.

modeNameToStartState	back to summary
public final Map<String, TokensStartState> modeNameToStartState Annotations @NotNull

modeToDFA	back to summary
public DFA[] modeToDFA Annotations @NotNull

modeToStartState	back to summary
public final List<TokensStartState> modeToStartState Annotations @NotNull

ruleToStartState	back to summary
public RuleStartState[] ruleToStartState Maps from rule index to starting state number.

ruleToStopState	back to summary
public RuleStopState[] ruleToStopState Maps from rule index to stop state number.

ruleToTokenType	back to summary
public int[] ruleToTokenType For lexer ATNs, this maps the rule index to the resulting token type. For parser ATNs, this maps the rule index to the generated bypass token type if the `ATNDeserializationOptions#isGenerateRuleBypassTransitions` deserialization option was specified; otherwise, this is `null`.

states	back to summary
public final List<ATNState> states Annotations @NotNull

Constructor Detail

ATN	back to summary
public ATN(ATNType grammarType, int maxTokenType) Used for runtime deserialization of ATNs from strings

Method Detail

addState	back to summary
public void addState(ATNState state)

clearDFA	back to summary
public final void clearDFA()

defineDecisionState	back to summary
public int defineDecisionState(DecisionState s)

defineMode	back to summary
public void defineMode(String name, TokensStartState s)

getCachedContext	back to summary
public PredictionContext getCachedContext(PredictionContext context)

getContextCacheSize	back to summary
public int getContextCacheSize()

getDecisionState	back to summary
public DecisionState getDecisionState(int decision)

getDecisionToDFA	back to summary
public final DFA[] getDecisionToDFA()

getExpectedTokens back to summary

getExpectedTokens	back to summary
public IntervalSet getExpectedTokens(int stateNumber, RuleContext context) Computes the set of input symbols which could follow ATN state number `stateNumber` in the specified full `context`. This method considers the complete parser context, but does not evaluate semantic predicates (i.e. all predicates encountered during the calculation are assumed true). If a path in the ATN exists from the starting state to the `RuleStopState` of the outermost context without matching any symbols, `Token#EOF` is added to the returned set. If `context` is `null`, it is treated as `ParserRuleContext#EMPTY`. Note that this does NOT give you the set of all tokens that could appear at a given token position in the input phrase. In other words, it does not answer: "Given a specific partial input phrase, return the set of all tokens that can follow the last token in the input phrase." The big difference is that with just the input, the parser could land right in the middle of a lookahead decision. Getting all possible tokens given a partial input stream is a separate computation. See https://github.com/antlr/antlr4/issues/1428 For this function, we are specifying an ATN state and call stack to compute what token(s) can come next and specifically: outside of a lookahead decision. That is what you want for error reporting and recovery upon parse error. Parameters stateNumber:int the ATN state number context:RuleContext the full parse context Returns:IntervalSet The set of potentially valid input symbols which could follow the specified state in the specified context. Annotations @NotNull Exceptions IllegalArgumentException: if the ATN does not contain a state with number `stateNumber`

public IntervalSet getExpectedTokens(int stateNumber, RuleContext context)

Computes the set of input symbols which could follow ATN state number stateNumber in the specified full context. This method considers the complete parser context, but does not evaluate semantic predicates (i.e. all predicates encountered during the calculation are assumed true). If a path in the ATN exists from the starting state to the RuleStopState of the outermost context without matching any symbols, Token#EOF is added to the returned set.

If context is null, it is treated as ParserRuleContext#EMPTY.

Note that this does NOT give you the set of all tokens that could appear at a given token position in the input phrase. In other words, it does not answer:

"Given a specific partial input phrase, return the set of all tokens that can follow the last token in the input phrase."

The big difference is that with just the input, the parser could land right in the middle of a lookahead decision. Getting all possible tokens given a partial input stream is a separate computation. See https://github.com/antlr/antlr4/issues/1428

For this function, we are specifying an ATN state and call stack to compute what token(s) can come next and specifically: outside of a lookahead decision. That is what you want for error reporting and recovery upon parse error.

Parameters

stateNumber:int: the ATN state number
context:RuleContext: the full parse context

Returns:IntervalSet

The set of potentially valid input symbols which could follow the specified state in the specified context.

Annotations

@NotNull

Exceptions

IllegalArgumentException:: if the ATN does not contain a state with number stateNumber

getNumberOfDecisions	back to summary
public int getNumberOfDecisions()

hasUnicodeSMPTransitions	back to summary
public boolean hasUnicodeSMPTransitions()

nextTokens back to summary

nextTokens	back to summary
public IntervalSet nextTokens(ATNState s, PredictionContext ctx) Compute the set of valid tokens that can occur starting in state `s`. If `ctx` is `PredictionContext#EMPTY_LOCAL`, the set of tokens will not include what can follow the rule surrounding `s`. In other words, the set will be restricted to tokens reachable staying within `s`'s rule. Annotations @NotNull

public IntervalSet nextTokens(ATNState s, PredictionContext ctx)

Compute the set of valid tokens that can occur starting in state s. If ctx is PredictionContext#EMPTY_LOCAL, the set of tokens will not include what can follow the rule surrounding s. In other words, the set will be restricted to tokens reachable staying within s's rule.

Annotations

@NotNull

nextTokens back to summary

nextTokens	back to summary
public IntervalSet nextTokens(ATNState s) Compute the set of valid tokens that can occur starting in `s` and staying in same rule. `Token#EPSILON` is in set if we reach end of rule. Annotations @NotNull

public IntervalSet nextTokens(ATNState s)

Compute the set of valid tokens that can occur starting in s and staying in same rule. Token#EPSILON is in set if we reach end of rule.

Annotations

@NotNull

removeState	back to summary
public void removeState(ATNState state)

setHasUnicodeSMPTransitions	back to summary
public void setHasUnicodeSMPTransitions(boolean value)

public Class ATN

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