Class ASTStepVisitor

java.lang.Object

com.oracle.truffle.regex.tregex.parser.ast.visitors.NFATraversalRegexASTVisitor

com.oracle.truffle.regex.tregex.nfa.ASTStepVisitor

public final class ASTStepVisitor
extends NFATraversalRegexASTVisitor

Regex AST visitor that will find convert all NFA successors of a given Term to ASTTransitions (by calculating their respective GroupBoundaries) and annotate for every successor which LookAheadAssertions and/or LookBehindAssertions it should be merged with. For example, when starting from Term "a" in the expression /a(b|(?=c)d)(?<=e)/, it will find the successors "b" and "d", where "d" must be merged with the successors of the look-ahead assertion ("c"), and both successors may be merged with the successors of the look-behind assertion ("e").

See Also:

• NFATraversalRegexASTVisitor

Field Summary

Fields inherited from class com.oracle.truffle.regex.tregex.parser.ast.visitors.NFATraversalRegexASTVisitor

ast

Constructor Summary

Constructors

Constructor	Description
ASTStepVisitor(RegexAST ast)

Method Summary

Modifier and Type	Method	Description
protected boolean	canPruneAfterUnconditionalFinalState()
protected void	enterLookAhead(LookAheadAssertion assertion)
protected boolean	isBuildingDFA()
protected void	leaveLookAhead(LookAheadAssertion assertion)
ASTStep	step(NFAState expandState)
protected void	visit(RegexASTNode target)	Visit the next successor found.

Methods inherited from class com.oracle.truffle.regex.tregex.parser.ast.visitors.NFATraversalRegexASTVisitor

calcTransitionGuardsResult, canTraverseCaret, caretsOnPath, dollarsOnPath, dumpTransitionGuards, getCurrentMatchedConditionGroups, getGroupBoundaries, getMatchedConditionGroups, getTransitionGuardsOnPath, getTraversableLookBehindAssertions, hasTransitionGuards, isReverse, run, setCanTraverseCaret, setMatchedConditionGroups, setReverse, setTraversableLookBehindAssertions

Methods inherited from class java.lang.Object

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

Constructor Details

ASTStepVisitor

public ASTStepVisitor(RegexAST ast)

Method Details

step

public ASTStep step(NFAState expandState)

visit

protected void visit(RegexASTNode target)

Description copied from class: NFATraversalRegexASTVisitor

Visit the next successor found.

Specified by:

visit in class NFATraversalRegexASTVisitor

enterLookAhead

protected void enterLookAhead(LookAheadAssertion assertion)

Specified by:

enterLookAhead in class NFATraversalRegexASTVisitor

leaveLookAhead

protected void leaveLookAhead(LookAheadAssertion assertion)

Specified by:

leaveLookAhead in class NFATraversalRegexASTVisitor

isBuildingDFA

protected boolean isBuildingDFA()

Specified by:

isBuildingDFA in class NFATraversalRegexASTVisitor

canPruneAfterUnconditionalFinalState

protected boolean canPruneAfterUnconditionalFinalState()

Specified by:

canPruneAfterUnconditionalFinalState in class NFATraversalRegexASTVisitor