com.oracle.truffle.regex.tregex.nodes.nfa

Class TRegexBacktrackingNFAExecutorNode

java.lang.Object

com.oracle.truffle.api.nodes.Node

com.oracle.truffle.regex.tregex.nodes.TRegexExecutorNode

com.oracle.truffle.regex.tregex.nodes.nfa.TRegexBacktrackingNFAExecutorNode

All Implemented Interfaces:

com.oracle.truffle.api.nodes.NodeInterface, Cloneable

public final class TRegexBacktrackingNFAExecutorNode
extends TRegexExecutorNode

This regex executor uses a backtracking algorithm on the NFA. It is used for all expressions that cannot be matched with the DFA, such as expressions with backreferences.

Nested Class Summary

Nested classes/interfaces inherited from class com.oracle.truffle.api.nodes.Node

com.oracle.truffle.api.nodes.Node.Child, com.oracle.truffle.api.nodes.Node.Children

Field Summary

Fields

Modifier and Type	Field and Description
static TRegexExecutorNode[]	NO_LOOK_AROUND_EXECUTORS

Fields inherited from class com.oracle.truffle.regex.tregex.nodes.TRegexExecutorNode

root

Constructor Summary

Constructors

Constructor and Description
TRegexBacktrackingNFAExecutorNode(PureNFAMap nfaMap, PureNFA nfa, TRegexExecutorNode[] lookAroundExecutors, CompilationBuffer compilationBuffer)

Method Summary

Modifier and Type	Method and Description
TRegexExecutorLocals	createLocals(Object input, int fromIndex, int index, int maxIndex)
Object	execute(TRegexExecutorLocals abstractLocals, boolean compactString)
protected static int	getBackRefBoundary(TRegexBacktrackingNFAExecutorLocals locals, PureNFATransition transition, int cgIndex, int index)
void	initialize(TRegexExecNode rootNode)
boolean	isForward()
boolean	isIgnoreCase()
protected boolean	lookAroundExecutorIsLiteral(PureNFAState s)
protected void	runMergeExplode(TRegexBacktrackingNFAExecutorLocals locals, boolean compactString)
protected int[]	runSubMatcher(TRegexBacktrackingNFAExecutorLocals subLocals, boolean compactString, PureNFAState lookAroundState)
protected static boolean	subMatchFailed(PureNFAState curState, int[] subMatchResult)
protected boolean	transitionMatches(TRegexBacktrackingNFAExecutorLocals locals, boolean compactString, PureNFATransition transition, int index, boolean atEnd, int c)
protected boolean	tryUpdateState(TRegexBacktrackingNFAExecutorLocals locals, boolean compactString, PureNFATransition transition, int index, boolean atEnd, int c) This method composes TRegexBacktrackingNFAExecutorNode.transitionMatches(com.oracle.truffle.regex.tregex.nodes.nfa.TRegexBacktrackingNFAExecutorLocals, boolean, com.oracle.truffle.regex.tregex.nfa.PureNFATransition, int, boolean, int) with TRegexBacktrackingNFAExecutorNode.updateState(com.oracle.truffle.regex.tregex.nodes.nfa.TRegexBacktrackingNFAExecutorLocals, com.oracle.truffle.regex.tregex.nfa.PureNFATransition, int).
protected void	updateState(TRegexBacktrackingNFAExecutorLocals locals, PureNFATransition transition, int index)
boolean	writesCaptureGroups() Returns true if this executor may write any new capture group boundaries.

Methods inherited from class com.oracle.truffle.regex.tregex.nodes.TRegexExecutorNode

countUpTo, getAstralProfile, getBMPProfile, getEncoding, getInputLength, getMaxIndex, getMinIndex, getNumberOfCaptureGroups, inputAdvance, inputAtBegin, inputAtEnd, inputHasNext, inputHasNext, inputHasNext, inputHasNext, inputIncNextIndexRaw, inputIncNextIndexRaw, inputIncRaw, inputIncRaw, inputIncRaw, inputIncRaw, inputIncRaw, inputIncRaw, inputIncRaw, inputIncRaw, inputReadAndDecode, inputReadAndDecode, inputReadRaw, inputReadRaw, inputReadRaw, inputReadRaw, inputSkip, inputSkipIntl, inputSkipReverse, inputUTF16IsHighSurrogate, inputUTF16IsLowSurrogate, inputUTF16ToCodePoint, rewindUpTo, setRoot

Methods inherited from class com.oracle.truffle.api.nodes.Node

accept, adoptChildren, atomic, atomic, copy, deepCopy, getChildren, getCost, getDebugProperties, getDescription, getEncapsulatingSourceSection, getLock, getParent, getRootNode, getSourceSection, insert, insert, isAdoptable, isSafelyReplaceableBy, notifyInserted, onReplace, replace, replace, reportPolymorphicSpecialize, toString

Methods inherited from class java.lang.Object

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

Field Detail

NO_LOOK_AROUND_EXECUTORS

public static final TRegexExecutorNode[] NO_LOOK_AROUND_EXECUTORS

Constructor Detail

TRegexBacktrackingNFAExecutorNode

public TRegexBacktrackingNFAExecutorNode(PureNFAMap nfaMap,
                                         PureNFA nfa,
                                         TRegexExecutorNode[] lookAroundExecutors,
                                         CompilationBuffer compilationBuffer)

Method Detail

initialize

public void initialize(TRegexExecNode rootNode)

writesCaptureGroups

public boolean writesCaptureGroups()

Description copied from class: TRegexExecutorNode

Returns true if this executor may write any new capture group boundaries.

Specified by:

writesCaptureGroups in class TRegexExecutorNode

isForward

public boolean isForward()

Specified by:

isForward in class TRegexExecutorNode

isIgnoreCase

public boolean isIgnoreCase()

createLocals

public TRegexExecutorLocals createLocals(Object input,
                                         int fromIndex,
                                         int index,
                                         int maxIndex)

Specified by:

createLocals in class TRegexExecutorNode

execute

public Object execute(TRegexExecutorLocals abstractLocals,
                      boolean compactString)

Specified by:

execute in class TRegexExecutorNode

runMergeExplode

protected void runMergeExplode(TRegexBacktrackingNFAExecutorLocals locals,
                               boolean compactString)

lookAroundExecutorIsLiteral

protected boolean lookAroundExecutorIsLiteral(PureNFAState s)

runSubMatcher

protected int[] runSubMatcher(TRegexBacktrackingNFAExecutorLocals subLocals,
                              boolean compactString,
                              PureNFAState lookAroundState)

subMatchFailed

protected static boolean subMatchFailed(PureNFAState curState,
                                        int[] subMatchResult)

transitionMatches

protected boolean transitionMatches(TRegexBacktrackingNFAExecutorLocals locals,
                                    boolean compactString,
                                    PureNFATransition transition,
                                    int index,
                                    boolean atEnd,
                                    int c)

getBackRefBoundary

protected static int getBackRefBoundary(TRegexBacktrackingNFAExecutorLocals locals,
                                        PureNFATransition transition,
                                        int cgIndex,
                                        int index)

updateState

protected void updateState(TRegexBacktrackingNFAExecutorLocals locals,
                           PureNFATransition transition,
                           int index)

tryUpdateState

protected boolean tryUpdateState(TRegexBacktrackingNFAExecutorLocals locals,
                                 boolean compactString,
                                 PureNFATransition transition,
                                 int index,
                                 boolean atEnd,
                                 int c)

This method composes TRegexBacktrackingNFAExecutorNode.transitionMatches(com.oracle.truffle.regex.tregex.nodes.nfa.TRegexBacktrackingNFAExecutorLocals, boolean, com.oracle.truffle.regex.tregex.nfa.PureNFATransition, int, boolean, int) with TRegexBacktrackingNFAExecutorNode.updateState(com.oracle.truffle.regex.tregex.nodes.nfa.TRegexBacktrackingNFAExecutorLocals, com.oracle.truffle.regex.tregex.nfa.PureNFATransition, int). It is somewhat equivalent to the following:

 if (transitionMatches(locals, compactString, transition, index, atEnd, c)) {
     updateState(locals, transition, index);
     return true;
 } else {
     return false;
 }
 

The key difference is that in this method, the TRegexBacktrackingNFAExecutorNode.updateState(com.oracle.truffle.regex.tregex.nodes.nfa.TRegexBacktrackingNFAExecutorLocals, com.oracle.truffle.regex.tregex.nfa.PureNFATransition, int) effects of quantifier guards are evaluated in parallel with their TRegexBacktrackingNFAExecutorNode.transitionMatches(com.oracle.truffle.regex.tregex.nodes.nfa.TRegexBacktrackingNFAExecutorLocals, boolean, com.oracle.truffle.regex.tregex.nfa.PureNFATransition, int, boolean, int) assertions. This more detailed behavior is necessary when working with NFA transitions that have complex chains of quantifier guards, such as the ones used in Ruby.

NB: This method writes to locals even if it returns false.