org.eclipse.xtext.xbase.parser

Class TokenSequencePreservingPartialParsingHelper

java.lang.Object

org.eclipse.xtext.xbase.parser.TokenSequencePreservingPartialParsingHelper

All Implemented Interfaces:

IPartialParsingHelper

public class TokenSequencePreservingPartialParsingHelper
extends Object
implements 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

Author:

Sebastian Zarnekow

Constructor Summary

Constructors

Constructor and Description
TokenSequencePreservingPartialParsingHelper()

Method Summary

Methods

Modifier and Type	Method and Description
protected PartialParsingPointers	calculatePartialParsingPointers(ICompositeNode oldRoot, ILeafNode left, ILeafNode right)
protected IParseResult	doParseRegion(IParser parser, PartialParsingPointers parsingPointers, ICompositeNode replaceMe, String reparseRegion)
protected void	filterInvalidRootNodes(List<ICompositeNode> validReplaceRootNodes)
protected IParseResult	fullyReparse(IParser parser, IParseResult previousParseResult, ReplaceRegion replaceRegion)
protected List<ICompositeNode>	getAllParents(ICompositeNode node)
protected ILeafNode	getLeftNode(Iterator<ILeafNode> leafNodes, int offset)
protected org.eclipse.emf.ecore.EObject	getOldSemanticElement(ICompositeNode replaceMe, PartialParsingPointers parsingPointers)
protected ICompositeNode	getReplacedNode(PartialParsingPointers parsingPointers)
protected ILeafNode	getRightNode(Iterator<ILeafNode> leafNodes, int offset)
protected String	insertChangeIntoReplaceRegion(ICompositeNode rootNode, ReplaceRegion region)
protected List<ICompositeNode>	internalFindValidReplaceRootNodeForChangeRegion(List<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(ICompositeNode node)
protected boolean	isBrokenPreviousState(IParseResult previousParseResult, int offset) Returns true if the previous document state was completely broken, e.g. the parser did not recover at all.
protected boolean	isInvalidRootNode(ICompositeNode candidate)
protected boolean	isSameTokenSequence(String originalText, String newText, int expectedLength)
protected boolean	isSameTokenSequence(org.antlr.runtime.TokenSource originalSource, org.antlr.runtime.TokenSource newSource, int expectedLength)
IParseResult	reparse(IParser parser, IParseResult previousParseResult, ReplaceRegion changedRegion)
protected void	replaceOldSemanticElement(org.eclipse.emf.ecore.EObject oldElement, IParseResult previousParseResult, 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 IParseResult reparse(IParser parser,
                   IParseResult previousParseResult,
                   ReplaceRegion changedRegion)

Specified by:

reparse in interface IPartialParsingHelper

isBrokenPreviousState

protected boolean isBrokenPreviousState(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,
                             IParseResult previousParseResult,
                             IParseResult newParseResult)

getOldSemanticElement

protected org.eclipse.emf.ecore.EObject getOldSemanticElement(ICompositeNode replaceMe,
                                                  PartialParsingPointers parsingPointers)

getReplacedNode

protected ICompositeNode getReplacedNode(PartialParsingPointers parsingPointers)

doParseRegion

protected IParseResult doParseRegion(IParser parser,
                         PartialParsingPointers parsingPointers,
                         ICompositeNode replaceMe,
                         String reparseRegion)

isSameTokenSequence

protected boolean isSameTokenSequence(String originalText,
                          String newText,
                          int expectedLength)

isSameTokenSequence

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

getLeftNode

protected ILeafNode getLeftNode(Iterator<ILeafNode> leafNodes,
                    int offset)

getRightNode

protected ILeafNode getRightNode(Iterator<ILeafNode> leafNodes,
                     int offset)

fullyReparse

protected IParseResult fullyReparse(IParser parser,
                        IParseResult previousParseResult,
                        ReplaceRegion replaceRegion)

unloadSemanticObject

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

insertChangeIntoReplaceRegion

protected String insertChangeIntoReplaceRegion(ICompositeNode rootNode,
                                   ReplaceRegion region)

calculatePartialParsingPointers

protected PartialParsingPointers calculatePartialParsingPointers(ICompositeNode oldRoot,
                                                     ILeafNode left,
                                                     ILeafNode right)

getAllParents

protected List<ICompositeNode> getAllParents(ICompositeNode node)

filterInvalidRootNodes

protected void filterInvalidRootNodes(List<ICompositeNode> validReplaceRootNodes)

isInvalidRootNode

protected boolean isInvalidRootNode(ICompositeNode candidate)

internalFindValidReplaceRootNodeForChangeRegion

protected List<ICompositeNode> internalFindValidReplaceRootNodeForChangeRegion(List<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(ICompositeNode node)