org.eclipse.xtext.xbase.parser

Class TokenSequencePreservingPartialParsingHelper

java.lang.Object

org.eclipse.xtext.xbase.parser.TokenSequencePreservingPartialParsingHelper

All Implemented Interfaces:

org.eclipse.xtext.parser.antlr.IPartialParsingHelper

public class TokenSequencePreservingPartialParsingHelper
extends java.lang.Object
implements org.eclipse.xtext.parser.antlr.IPartialParsingHelper

A customized partial parsing helper that falls eagerly back to a full parse as soon as the new token sequence would be different from the old one. This approach allows to benefit from partial parsing whenever a token content is edited (e.g. the content of a comment, identifier or string literal) while not producing bogus lookahead information. Mostly copied and refactored from the default implementation.

Since:

2.9

Noreference:

This class is not intended to be referenced by clients.

Noextend:

This class is not intended to be subclassed by clients.

Noinstantiate:

This class is not intended to be instantiated by clients.

Constructor Summary

Constructors

Constructor and Description
TokenSequencePreservingPartialParsingHelper()

Method Summary

Modifier and Type	Method and Description
protected org.eclipse.xtext.parser.impl.PartialParsingPointers	calculatePartialParsingPointers(org.eclipse.xtext.nodemodel.ICompositeNode oldRoot, org.eclipse.xtext.nodemodel.ILeafNode left, org.eclipse.xtext.nodemodel.ILeafNode right)
protected org.eclipse.xtext.parser.IParseResult	doParseRegion(org.eclipse.xtext.parser.IParser parser, org.eclipse.xtext.parser.impl.PartialParsingPointers parsingPointers, org.eclipse.xtext.nodemodel.ICompositeNode replaceMe, java.lang.String reparseRegion)
protected void	filterInvalidRootNodes(java.util.List<org.eclipse.xtext.nodemodel.ICompositeNode> validReplaceRootNodes)
protected org.eclipse.xtext.parser.IParseResult	fullyReparse(org.eclipse.xtext.parser.IParser parser, org.eclipse.xtext.parser.IParseResult previousParseResult, org.eclipse.xtext.util.ReplaceRegion replaceRegion)
protected java.util.List<org.eclipse.xtext.nodemodel.ICompositeNode>	getAllParents(org.eclipse.xtext.nodemodel.ICompositeNode node)
protected org.eclipse.xtext.nodemodel.ILeafNode	getLeftNode(java.util.Iterator<org.eclipse.xtext.nodemodel.ILeafNode> leafNodes, int offset)
protected org.eclipse.emf.ecore.EObject	getOldSemanticElement(org.eclipse.xtext.nodemodel.ICompositeNode replaceMe, org.eclipse.xtext.parser.impl.PartialParsingPointers parsingPointers)
protected org.eclipse.xtext.nodemodel.ICompositeNode	getReplacedNode(org.eclipse.xtext.parser.impl.PartialParsingPointers parsingPointers)
protected org.eclipse.xtext.nodemodel.ILeafNode	getRightNode(java.util.Iterator<org.eclipse.xtext.nodemodel.ILeafNode> leafNodes, int offset)
protected java.lang.String	insertChangeIntoReplaceRegion(org.eclipse.xtext.nodemodel.ICompositeNode rootNode, org.eclipse.xtext.util.ReplaceRegion region)
protected java.util.List<org.eclipse.xtext.nodemodel.ICompositeNode>	internalFindValidReplaceRootNodeForChangeRegion(java.util.List<org.eclipse.xtext.nodemodel.ICompositeNode> nodesEnclosingRegion) Investigates the composite nodes containing the changed region and collects a list of nodes which could possibly replaced by a partial parse.
protected boolean	isActionNode(org.eclipse.xtext.nodemodel.ICompositeNode node)
protected boolean	isBrokenPreviousState(org.eclipse.xtext.parser.IParseResult previousParseResult, int offset) Returns true if the previous document state was completely broken, e.g.
protected boolean	isInvalidRootNode(org.eclipse.xtext.nodemodel.ICompositeNode candidate)
protected boolean	isSameTokenSequence(java.lang.String originalText, java.lang.String newText, int expectedLength)
protected boolean	isSameTokenSequence(org.antlr.runtime.TokenSource originalSource, org.antlr.runtime.TokenSource newSource, int expectedLength)
org.eclipse.xtext.parser.IParseResult	reparse(org.eclipse.xtext.parser.IParser parser, org.eclipse.xtext.parser.IParseResult previousParseResult, org.eclipse.xtext.util.ReplaceRegion changedRegion)
protected void	replaceOldSemanticElement(org.eclipse.emf.ecore.EObject oldElement, org.eclipse.xtext.parser.IParseResult previousParseResult, org.eclipse.xtext.parser.IParseResult newParseResult)
protected void	unloadSemanticObject(org.eclipse.emf.ecore.EObject object)

Methods inherited from class java.lang.Object

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

Constructor Detail

TokenSequencePreservingPartialParsingHelper

public TokenSequencePreservingPartialParsingHelper()

Method Detail

reparse

public org.eclipse.xtext.parser.IParseResult reparse(org.eclipse.xtext.parser.IParser parser,
                                                     org.eclipse.xtext.parser.IParseResult previousParseResult,
                                                     org.eclipse.xtext.util.ReplaceRegion changedRegion)

Specified by:

reparse in interface org.eclipse.xtext.parser.antlr.IPartialParsingHelper

isBrokenPreviousState

protected boolean isBrokenPreviousState(org.eclipse.xtext.parser.IParseResult previousParseResult,
                                        int offset)

Returns true if the previous document state was completely broken, e.g. the parser did not recover at all. This may happen e.g. in Xtend for documents like

import static class C {}

where the class keyword is consumed as an invalid token in the import declaration and everything thereafter is unrecoverable.

replaceOldSemanticElement

protected void replaceOldSemanticElement(org.eclipse.emf.ecore.EObject oldElement,
                                         org.eclipse.xtext.parser.IParseResult previousParseResult,
                                         org.eclipse.xtext.parser.IParseResult newParseResult)

getOldSemanticElement

protected org.eclipse.emf.ecore.EObject getOldSemanticElement(org.eclipse.xtext.nodemodel.ICompositeNode replaceMe,
                                                              org.eclipse.xtext.parser.impl.PartialParsingPointers parsingPointers)

getReplacedNode

protected org.eclipse.xtext.nodemodel.ICompositeNode getReplacedNode(org.eclipse.xtext.parser.impl.PartialParsingPointers parsingPointers)

doParseRegion

protected org.eclipse.xtext.parser.IParseResult doParseRegion(org.eclipse.xtext.parser.IParser parser,
                                                              org.eclipse.xtext.parser.impl.PartialParsingPointers parsingPointers,
                                                              org.eclipse.xtext.nodemodel.ICompositeNode replaceMe,
                                                              java.lang.String reparseRegion)

isSameTokenSequence

protected boolean isSameTokenSequence(java.lang.String originalText,
                                      java.lang.String newText,
                                      int expectedLength)

isSameTokenSequence

protected boolean isSameTokenSequence(org.antlr.runtime.TokenSource originalSource,
                                      org.antlr.runtime.TokenSource newSource,
                                      int expectedLength)

getLeftNode

protected org.eclipse.xtext.nodemodel.ILeafNode getLeftNode(java.util.Iterator<org.eclipse.xtext.nodemodel.ILeafNode> leafNodes,
                                                            int offset)

getRightNode

protected org.eclipse.xtext.nodemodel.ILeafNode getRightNode(java.util.Iterator<org.eclipse.xtext.nodemodel.ILeafNode> leafNodes,
                                                             int offset)

fullyReparse

protected org.eclipse.xtext.parser.IParseResult fullyReparse(org.eclipse.xtext.parser.IParser parser,
                                                             org.eclipse.xtext.parser.IParseResult previousParseResult,
                                                             org.eclipse.xtext.util.ReplaceRegion replaceRegion)

unloadSemanticObject

protected void unloadSemanticObject(org.eclipse.emf.ecore.EObject object)

insertChangeIntoReplaceRegion

protected java.lang.String insertChangeIntoReplaceRegion(org.eclipse.xtext.nodemodel.ICompositeNode rootNode,
                                                         org.eclipse.xtext.util.ReplaceRegion region)

calculatePartialParsingPointers

protected org.eclipse.xtext.parser.impl.PartialParsingPointers calculatePartialParsingPointers(org.eclipse.xtext.nodemodel.ICompositeNode oldRoot,
                                                                                               org.eclipse.xtext.nodemodel.ILeafNode left,
                                                                                               org.eclipse.xtext.nodemodel.ILeafNode right)

getAllParents

protected java.util.List<org.eclipse.xtext.nodemodel.ICompositeNode> getAllParents(org.eclipse.xtext.nodemodel.ICompositeNode node)

filterInvalidRootNodes

protected void filterInvalidRootNodes(java.util.List<org.eclipse.xtext.nodemodel.ICompositeNode> validReplaceRootNodes)

isInvalidRootNode

protected boolean isInvalidRootNode(org.eclipse.xtext.nodemodel.ICompositeNode candidate)

internalFindValidReplaceRootNodeForChangeRegion

protected java.util.List<org.eclipse.xtext.nodemodel.ICompositeNode> internalFindValidReplaceRootNodeForChangeRegion(java.util.List<org.eclipse.xtext.nodemodel.ICompositeNode> nodesEnclosingRegion)

Investigates the composite nodes containing the changed region and collects a list of nodes which could possibly replaced by a partial parse. Such a node has a parent that consumes all his current lookahead tokens and all of these tokens are located before the changed region.

isActionNode

protected boolean isActionNode(org.eclipse.xtext.nodemodel.ICompositeNode node)