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

Class BackReference

java.lang.Object

com.oracle.truffle.regex.tregex.parser.ast.RegexASTNode

com.oracle.truffle.regex.tregex.parser.ast.Term

com.oracle.truffle.regex.tregex.parser.ast.QuantifiableTerm

com.oracle.truffle.regex.tregex.parser.ast.BackReference

All Implemented Interfaces:

AbstractState<Term,ASTTransition>, JsonConvertible

public class BackReference
extends QuantifiableTerm

A reference to the contents of a previously matched capturing group.

Corresponds to the goal symbol DecimalEscape in the ECMAScript RegExp syntax.

Currently not implemented in TRegex and so any use of this node type causes TRegex to bail out.

Method Summary

Modifier and Type	Method and Description
BackReference	copy(RegexAST ast) Copy this node only, without any child nodes.
BackReference	copyRecursive(RegexAST ast, CompilationBuffer compilationBuffer) Recursively copy this subtree.
boolean	equalsSemantic(RegexASTNode obj, boolean ignoreQuantifier)
int	getGroupNr() Returns the capture group number this back-reference is referring to, e.g.
boolean	isForwardReference()
boolean	isNestedBackReference()
boolean	isNestedOrForwardReference() Returns true iff this "back-reference" is actually a reference to its own parent group or a later group in the expression.
boolean	isUnrollingCandidate() Returns true iff the parser should try to unroll this term's quantifier.
void	setForwardReference()
void	setNestedBackReference()
JsonValue	toJson()
String	toString()

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

equalsSemantic, getQuantifier, getSubTreeParent, hasNotUnrolledQuantifier, hasQuantifier, quantifierToString, setQuantifier

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

getSeqIndex, setSeqIndex

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

asAtomicGroup, asBackReference, asCharacterClass, asGroup, asLookAheadAssertion, asLookAroundAssertion, asLookBehindAssertion, asMatchFound, asPositionAssertion, asQuantifiableTerm, asSequence, asSubtreeRootNode, astNodeId, endsWithDollar, getFlags, getId, getMaxPath, getMinPath, getParent, hasBackReferences, hasCaptureGroups, hasCaret, hasDollar, hasEmptyGuard, hasLookAheads, hasLookBehinds, hasLoops, hasQuantifiers, idInitialized, incMaxPath, incMaxPath, incMinPath, incMinPath, isAtomicGroup, isBackReference, isCaret, isCharacterClass, isDead, isDollar, isExpandedQuantifier, isFlagSet, isGroup, isInLookAheadAssertion, isInLookBehindAssertion, isLookAheadAssertion, isLookAroundAssertion, isLookBehindAssertion, isMatchFound, isPositionAssertion, isPrefix, isQuantifiableTerm, isRoot, isSequence, isSubtreeRoot, markAsDead, setDead, setEmptyGuard, setEndsWithDollar, setEndsWithDollar, setExpandedQuantifier, setFlag, setFlag, setFlags, setHasBackReferences, setHasCaptureGroups, setHasCaret, setHasCaret, setHasDollar, setHasDollar, setHasLookAheads, setHasLookBehinds, setHasLoops, setHasLoops, setHasQuantifiers, setId, setMaxPath, setMinPath, setParent, setPrefix, setStartsWithCaret, setStartsWithCaret, startsWithCaret, toJson, toStringWithID

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.oracle.truffle.regex.tregex.automaton.AbstractState

getId

Method Detail

copy

public BackReference copy(RegexAST ast)

Description copied from class: RegexASTNode

Copy this node only, without any child nodes. The ID and minPath of the copied nodes is left unset.

Specified by:

copy in class QuantifiableTerm

Parameters:

ast - RegexAST the node should belong to.

Returns:

A shallow copy of this node.

copyRecursive

public BackReference copyRecursive(RegexAST ast,
                                   CompilationBuffer compilationBuffer)

Description copied from class: RegexASTNode

Recursively copy this subtree. This method should be used instead of CopyVisitor if the copying process is required to be thread-safe. The ID and minPath of the copied nodes is left unset.

Specified by:

copyRecursive in class Term

Parameters:

ast - RegexAST the new nodes should belong to.

Returns:

A deep copy of this node.

getGroupNr

public int getGroupNr()

Returns the capture group number this back-reference is referring to, e.g. the referenced group of \1 is 1.

isNestedBackReference

public boolean isNestedBackReference()

setNestedBackReference

public void setNestedBackReference()

isForwardReference

public boolean isForwardReference()

setForwardReference

public void setForwardReference()

isNestedOrForwardReference

public boolean isNestedOrForwardReference()

Returns true iff this "back-reference" is actually a reference to its own parent group or a later group in the expression. In JavaScript, such nested/forward references will always match the empty string.

isUnrollingCandidate

public boolean isUnrollingCandidate()

Description copied from class: QuantifiableTerm

Returns true iff the parser should try to unroll this term's quantifier.

Specified by:

isUnrollingCandidate in class QuantifiableTerm

equalsSemantic

public boolean equalsSemantic(RegexASTNode obj,
                              boolean ignoreQuantifier)

Specified by:

equalsSemantic in class QuantifiableTerm

toString

public String toString()

Overrides:

toString in class Object

toJson

public JsonValue toJson()