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

Class MatchFound

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.MatchFound

All Implemented Interfaces:

IndexedState, JsonConvertible

public class MatchFound
extends Term

MatchFound nodes are RegexASTNodes that represent the initial/final states of the non-deterministic finite state automaton generated from the regular expression.

Regular expressions are translated into non-deterministic finite state automata, with each RegexASTNode in the RegexAST contributing some of the states or transitions. The MatchFound nodes are those that contribute the final (accepting) states. The root group of every regular expression is linked (using the 'next' pointer) to a single MatchFound node. Other MatchFound nodes appear in look-behind and look-ahead assertions, where they contribute the final states of their subautomata (look-around assertions generate subautomata which are then joined with the root automaton using a product construction).

MatchFound nodes are also used as initial states (the initial states of the forward search automaton are the final states of the reverse search automaton). Therefore, there is a set of MatchFound nodes used as final states in forward search (reachable by 'next' pointers) and as initial states in reverse search and a set of MatchFound nodes used as final states in reverse search (reachable by 'prev' pointers) and as initial states in forward search. MatchFound being used as NFA initial states is also why they can have a next-pointer ( MatchFound.getNext()) themselves (see RegexAST.getNFAUnAnchoredInitialState(int)).

Field Summary

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

FLAG_CHARACTER_CLASS_WAS_SINGLE_CHAR, FLAG_EMPTY_GUARD, FLAG_GROUP_EXPANDED_QUANTIFIER, FLAG_GROUP_LOOP, FLAG_HAS_LOOPS, FLAG_LOOK_AROUND_NEGATED

Constructor Summary

Constructors

Constructor and Description
MatchFound()

Method Summary

Modifier and Type	Method and Description
MatchFound	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, boolean ignoreQuantifier)
RegexASTNode	getNext()
void	setNext(RegexASTNode next)
JsonValue	toJson()
String	toString()

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

equalsSemantic, getQuantifier, getSeqIndex, getSubTreeParent, hasQuantifier, quantifierToString, setQuantifier, setSeqIndex

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

astNodeId, endsWithDollar, getId, getMaxPath, getMinPath, getParent, hasEmptyGuard, hasLoops, idInitialized, incMaxPath, incMaxPath, incMinPath, incMinPath, isDead, isFlagSet, isInLookAheadAssertion, isInLookBehindAssertion, isPrefix, markAsDead, setEmptyGuard, setEndsWithDollar, setEndsWithDollar, setFlag, setFlag, setHasLoops, setHasLoops, setId, setMaxPath, setMinPath, setParent, setPrefix, setStartsWithCaret, setStartsWithCaret, startsWithCaret, toJson, toStringWithID

Methods inherited from class java.lang.Object

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

Constructor Detail

MatchFound

public MatchFound()

Method Detail

copy

public MatchFound 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 Term

Parameters:

ast - RegexAST the new nodes should belong to.

Returns:

A shallow or deep copy of this node.

getNext

public RegexASTNode getNext()

setNext

public void setNext(RegexASTNode next)

equalsSemantic

public boolean equalsSemantic(RegexASTNode obj,
                              boolean ignoreQuantifier)

Specified by:

equalsSemantic in class Term

toString

public String toString()

Overrides:

toString in class Object

toJson

public JsonValue toJson()