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

Class LookBehindAssertion

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.RegexASTSubtreeRootNode

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

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

All Implemented Interfaces:

AbstractState<Term,ASTTransition>, RegexASTVisitorIterable, JsonConvertible

public class LookBehindAssertion
extends LookAroundAssertion

An assertion that succeeds depending on whether or not text preceding the current position matches a given regular expression.

Corresponds to the ( ? <= Disjunction ) and ( ? <! Disjunction ) right-hand sides of the Assertion goal symbol in the ECMAScript RegExp syntax.

Currently, the fragment of regular expressions that TRegex supports in lookbehind assertions is limited to so-called "literal" regular expressions, consisting only of concatenations and character classes (which generalize literal characters). The method LookAroundAssertion.isLiteral() verifies whether the body of the assertion (RegexASTSubtreeRootNode.getGroup()) is of this form.

Method Summary

Modifier and Type	Method and Description
LookBehindAssertion	copy(RegexAST ast, boolean recursive) Copy this node, in one of the following ways: if recursive is true, recursively copy this subtree.
boolean	equalsSemantic(RegexASTNode obj)
String	getPrefix()
JsonValue	toJson()

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

endsWithCharClass, getLiteralLength, isLiteral, isNegated, isSingleCCNonCapturingLiteral, setNegated, startsWithCharClass

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

getAnchoredFinalState, getAnchoredInitialState, getGroup, getMatchFound, getSubTreeId, getUnAnchoredInitialState, resetVisitorIterator, setAnchoredFinalState, setAnchoredInitialState, setGroup, setMatchFound, setSubTreeId, setUnAnchoredInitialState, subTreeIdInitialized, toJson, toString, visitorGetNext, visitorHasNext

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

getSeqIndex, getSubTreeParent, setSeqIndex

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

asBackReference, asCharacterClass, asGroup, asLookAheadAssertion, asLookAroundAssertion, asLookBehindAssertion, asMatchFound, asPositionAssertion, asQuantifiableTerm, asSequence, astNodeId, endsWithDollar, getFlags, getId, getMaxPath, getMinPath, getParent, hasBackReferences, hasCaptureGroups, hasCaret, hasDollar, hasEmptyGuard, hasLookAheads, hasLookBehinds, hasLoops, hasQuantifiers, idInitialized, incMaxPath, incMaxPath, incMinPath, incMinPath, 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, toStringWithID

Methods inherited from class java.lang.Object

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

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

getId

Method Detail

copy

public LookBehindAssertion copy(RegexAST ast,
                                boolean recursive)

Description copied from class: RegexASTNode

Copy this node, in one of the following ways:

• if recursive is true, recursively copy this subtree. This method should be used instead of CopyVisitor if the copying process is required to be thread-safe.
• else, copy this node only, without any child nodes.

In both cases, the ID and minPath of the copied nodes is left unset.

Specified by:

copy in class RegexASTSubtreeRootNode

Parameters:

ast - RegexAST the new nodes should belong to.

Returns:

A shallow or deep copy of this node.

getPrefix

public String getPrefix()

Specified by:

getPrefix in class RegexASTSubtreeRootNode

equalsSemantic

public boolean equalsSemantic(RegexASTNode obj)

Specified by:

equalsSemantic in class RegexASTNode

toJson

public JsonValue toJson()