ANTLR 4.13.1 · org.antlr.v4.runtime.atn.LL1Analyzer

Modifier and Type	Field and Description
public final ATN	atn
public static final int	HIT_PRED Special value added to the lookahead sets to indicate that we hit a predicate during analysis if `seeThruPreds==false`.

Access	Constructor and Description
public	LL1Analyzer(ATN atn)

Method Summary

Modifier and Type	Method and Description
protected void	_LOOK(ATNState the ATN state. s, ATNState the ATN state to stop at. This can be a `BlockEndState` to detect epsilon paths through a closure. stopState, PredictionContext The outer context, or `null` if the outer context should not be used. ctx, IntervalSet The result lookahead set. look, Set<ATNConfig> A set used for preventing epsilon closures in the ATN from causing a stack overflow. Outside code should pass `new HashSet<ATNConfig>` for this argument. lookBusy, BitSet A set used for preventing left recursion in the ATN from causing a stack overflow. Outside code should pass `new BitSet()` for this argument. calledRuleStack, boolean `true` to true semantic predicates as implicitly `true` and "see through them", otherwise `false` to treat semantic predicates as opaque and add `HIT_PRED` to the result if one is encountered. seeThruPreds, boolean Add `Token#EOF` to the result if the end of the outermost context is reached. This parameter has no effect if `ctx` is `null`. addEOF) Compute set of tokens that can follow `s` in the ATN in the specified `ctx`.
public IntervalSet[]	Returns: the expected symbols for each outgoing transition of `s`. getDecisionLookahead(ATNState the ATN state s) Calculates the SLL(1) expected lookahead set for each outgoing transition of an `ATNState`.
public IntervalSet	Returns: The set of tokens that can follow `s` in the ATN in the specified `ctx`. LOOK(ATNState the ATN state s, RuleContext the complete parser context, or `null` if the context should be ignored ctx) Compute set of tokens that can follow `s` in the ATN in the specified `ctx`.
public IntervalSet	Returns: The set of tokens that can follow `s` in the ATN in the specified `ctx`. LOOK(ATNState the ATN state s, ATNState the ATN state to stop at. This can be a `BlockEndState` to detect epsilon paths through a closure. stopState, RuleContext the complete parser context, or `null` if the context should be ignored ctx) Compute set of tokens that can follow `s` in the ATN in the specified `ctx`.

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

atn	back to summary
public final ATN atn

HIT_PRED	back to summary
public static final int HIT_PRED Special value added to the lookahead sets to indicate that we hit a predicate during analysis if `seeThruPreds==false`.

LL1Analyzer	back to summary
public LL1Analyzer(ATN atn)

Method Detail

_LOOK back to summary

_LOOK	back to summary
protected void _LOOK(ATNState s, ATNState stopState, PredictionContext ctx, IntervalSet look, Set<ATNConfig> lookBusy, BitSet calledRuleStack, boolean seeThruPreds, boolean addEOF) Compute set of tokens that can follow `s` in the ATN in the specified `ctx`. If `ctx` is `null` and `stopState` or the end of the rule containing `s` is reached, `Token#EPSILON` is added to the result set. If `ctx` is not `null` and `addEOF` is `true` and `stopState` or the end of the outermost rule is reached, `Token#EOF` is added to the result set. Parameters s:ATNState the ATN state. stopState:ATNState the ATN state to stop at. This can be a `BlockEndState` to detect epsilon paths through a closure. ctx:PredictionContext The outer context, or `null` if the outer context should not be used. look:IntervalSet The result lookahead set. lookBusy:Set<ATNConfig> A set used for preventing epsilon closures in the ATN from causing a stack overflow. Outside code should pass `new HashSet<ATNConfig>` for this argument. calledRuleStack:BitSet A set used for preventing left recursion in the ATN from causing a stack overflow. Outside code should pass `new BitSet()` for this argument. seeThruPreds:boolean `true` to true semantic predicates as implicitly `true` and "see through them", otherwise `false` to treat semantic predicates as opaque and add `HIT_PRED` to the result if one is encountered. addEOF:boolean Add `Token#EOF` to the result if the end of the outermost context is reached. This parameter has no effect if `ctx` is `null`.

protected void _LOOK(ATNState s, ATNState stopState, PredictionContext ctx, IntervalSet look, Set<ATNConfig> lookBusy, BitSet calledRuleStack, boolean seeThruPreds, boolean addEOF)

Compute set of tokens that can follow s in the ATN in the specified ctx.

If ctx is null and stopState or the end of the rule containing s is reached, Token#EPSILON is added to the result set. If ctx is not null and addEOF is true and stopState or the end of the outermost rule is reached, Token#EOF is added to the result set.

Parameters

s:ATNState: the ATN state.
stopState:ATNState: the ATN state to stop at. This can be a BlockEndState to detect epsilon paths through a closure.
ctx:PredictionContext: The outer context, or null if the outer context should not be used.
look:IntervalSet: The result lookahead set.
lookBusy:Set<ATNConfig>: A set used for preventing epsilon closures in the ATN from causing a stack overflow. Outside code should pass new HashSet<ATNConfig> for this argument.
calledRuleStack:BitSet: A set used for preventing left recursion in the ATN from causing a stack overflow. Outside code should pass new BitSet() for this argument.
seeThruPreds:boolean: true to true semantic predicates as implicitly true and "see through them", otherwise false to treat semantic predicates as opaque and add HIT_PRED to the result if one is encountered.
addEOF:boolean: Add Token#EOF to the result if the end of the outermost context is reached. This parameter has no effect if ctx is null.

getDecisionLookahead back to summary

getDecisionLookahead	back to summary
public IntervalSet[] getDecisionLookahead(ATNState s) Calculates the SLL(1) expected lookahead set for each outgoing transition of an `ATNState`. The returned array has one element for each outgoing transition in `s`. If the closure from transition i leads to a semantic predicate before matching a symbol, the element at index i of the result will be `null`. Parameters s:ATNState the ATN state Returns:IntervalSet[] the expected symbols for each outgoing transition of `s`.

public IntervalSet[] getDecisionLookahead(ATNState s)

Calculates the SLL(1) expected lookahead set for each outgoing transition of an ATNState. The returned array has one element for each outgoing transition in s. If the closure from transition i leads to a semantic predicate before matching a symbol, the element at index i of the result will be null.

Parameters

s:ATNState: the ATN state

Returns:IntervalSet[]

the expected symbols for each outgoing transition of s.

LOOK back to summary

LOOK	back to summary
public IntervalSet LOOK(ATNState s, RuleContext ctx) Compute set of tokens that can follow `s` in the ATN in the specified `ctx`. If `ctx` is `null` and the end of the rule containing `s` is reached, `Token#EPSILON` is added to the result set. If `ctx` is not `null` and the end of the outermost rule is reached, `Token#EOF` is added to the result set. Parameters s:ATNState the ATN state ctx:RuleContext the complete parser context, or `null` if the context should be ignored Returns:IntervalSet The set of tokens that can follow `s` in the ATN in the specified `ctx`.

public IntervalSet LOOK(ATNState s, RuleContext ctx)

Compute set of tokens that can follow s in the ATN in the specified ctx.

If ctx is null and the end of the rule containing s is reached, Token#EPSILON is added to the result set. If ctx is not null and the end of the outermost rule is reached, Token#EOF is added to the result set.

Parameters

s:ATNState: the ATN state
ctx:RuleContext: the complete parser context, or null if the context should be ignored

Returns:IntervalSet

The set of tokens that can follow s in the ATN in the specified ctx.

LOOK back to summary

LOOK	back to summary
public IntervalSet LOOK(ATNState s, ATNState stopState, RuleContext ctx) Compute set of tokens that can follow `s` in the ATN in the specified `ctx`. If `ctx` is `null` and the end of the rule containing `s` is reached, `Token#EPSILON` is added to the result set. If `ctx` is not `null` and the end of the outermost rule is reached, `Token#EOF` is added to the result set. Parameters s:ATNState the ATN state stopState:ATNState the ATN state to stop at. This can be a `BlockEndState` to detect epsilon paths through a closure. ctx:RuleContext the complete parser context, or `null` if the context should be ignored Returns:IntervalSet The set of tokens that can follow `s` in the ATN in the specified `ctx`.

public IntervalSet LOOK(ATNState s, ATNState stopState, RuleContext ctx)

Compute set of tokens that can follow s in the ATN in the specified ctx.

Parameters

s:ATNState: the ATN state
stopState:ATNState: the ATN state to stop at. This can be a BlockEndState to detect epsilon paths through a closure.
ctx:RuleContext: the complete parser context, or null if the context should be ignored

Returns:IntervalSet

The set of tokens that can follow s in the ATN in the specified ctx.

public Class LL1Analyzer

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail