/*******************************************************************************
* Copyright (c) 2000, 2004 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Common Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/cpl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.rubypeople.rdt.internal.ui.text;
import java.util.Arrays;
import org.eclipse.jface.text.Assert;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITypedRegion;
import org.eclipse.jface.text.Region;
import org.eclipse.jface.text.TextUtilities;
/**
* Utility methods for heuristic based Ruby manipulations in an incomplete Ruby source file.
*
* <p>An instance holds some internal position in the document and is therefore not threadsafe.</p>
*
* @since 3.0
*/
public class RubyHeuristicScanner implements Symbols {
/**
* Returned by all methods when the requested position could not be found, or if a
* {@link BadLocationException} was thrown while scanning.
*/
public static final int NOT_FOUND= -1;
/**
* Special bound parameter that means either -1 (backward scanning) or
* <code>fDocument.getLength()</code> (forward scanning).
*/
public static final int UNBOUND= -2;
/* character constants */
private static final char LBRACE= '{';
private static final char RBRACE= '}';
private static final char LPAREN= '(';
private static final char RPAREN= ')';
private static final char SEMICOLON= ';';
private static final char COLON= ':';
private static final char COMMA= ',';
private static final char LBRACKET= '[';
private static final char RBRACKET= ']';
private static final char QUESTIONMARK= '?';
private static final char EQUAL= '=';
/**
* Specifies the stop condition, upon which the <code>scanXXX</code> methods will decide whether
* to keep scanning or not. This interface may implemented by clients.
*/
public interface StopCondition {
/**
* Instructs the scanner to return the current position.
*
* @param ch the char at the current position
* @param position the current position
* @param forward the iteration direction
* @return <code>true</code> if the stop condition is met.
*/
boolean stop(char ch, int position, boolean forward);
}
/**
* Stops upon a non-whitespace (as defined by {@link Character#isWhitespace(char)}) character.
*/
private static class NonWhitespace implements StopCondition {
/*
* @see org.eclipse.jdt.internal.ui.text.RubyHeuristicScanner.StopCondition#stop(char)
*/
public boolean stop(char ch, int position, boolean forward) {
return !Character.isWhitespace(ch);
}
}
/**
* Stops upon a non-whitespace character in the default partition.
*
* @see NonWhitespace
*/
private class NonWhitespaceDefaultPartition extends NonWhitespace {
/*
* @see org.eclipse.jdt.internal.ui.text.RubyHeuristicScanner.StopCondition#stop(char)
*/
public boolean stop(char ch, int position, boolean forward) {
return super.stop(ch, position, true) && isDefaultPartition(position);
}
}
/**
* Stops upon a non-java identifier (as defined by {@link Character#isRubyIdentifierPart(char)}) character.
*/
private static class NonRubyIdentifierPart implements StopCondition {
/*
* @see org.eclipse.jdt.internal.ui.text.RubyHeuristicScanner.StopCondition#stop(char)
*/
public boolean stop(char ch, int position, boolean forward) {
return !Character.isJavaIdentifierPart(ch);
}
}
/**
* Stops upon a non-java identifier character in the default partition.
*
* @see NonRubyIdentifierPart
*/
private class NonRubyIdentifierPartDefaultPartition extends NonRubyIdentifierPart {
/*
* @see org.eclipse.jdt.internal.ui.text.RubyHeuristicScanner.StopCondition#stop(char)
*/
public boolean stop(char ch, int position, boolean forward) {
return super.stop(ch, position, true) || !isDefaultPartition(position);
}
}
/**
* Stops upon a character in the default partition that matches the given character list.
*/
private class CharacterMatch implements StopCondition {
private final char[] fChars;
/**
* Creates a new instance.
* @param ch the single character to match
*/
public CharacterMatch(char ch) {
this(new char[] {ch});
}
/**
* Creates a new instance.
* @param chars the chars to match.
*/
public CharacterMatch(char[] chars) {
Assert.isNotNull(chars);
Assert.isTrue(chars.length > 0);
fChars= chars;
Arrays.sort(chars);
}
/*
* @see org.eclipse.jdt.internal.ui.text.RubyHeuristicScanner.StopCondition#stop(char, int)
*/
public boolean stop(char ch, int position, boolean forward) {
return Arrays.binarySearch(fChars, ch) >= 0 && isDefaultPartition(position);
}
}
/**
* Acts like character match, but skips all scopes introduced by parenthesis, brackets, and
* braces.
*/
protected class SkippingScopeMatch extends CharacterMatch {
private char fOpening, fClosing;
private int fDepth= 0;
/**
* Creates a new instance.
* @param ch the single character to match
*/
public SkippingScopeMatch(char ch) {
super(ch);
}
/**
* Creates a new instance.
* @param chars the chars to match.
*/
public SkippingScopeMatch(char[] chars) {
super(chars);
}
/*
* @see org.eclipse.jdt.internal.ui.text.RubyHeuristicScanner.StopCondition#stop(char, int)
*/
public boolean stop(char ch, int position, boolean forward) {
if (fDepth == 0 && super.stop(ch, position, true))
return true;
else if (ch == fOpening)
fDepth++;
else if (ch == fClosing) {
fDepth--;
if (fDepth == 0) {
fOpening= 0;
fClosing= 0;
}
} else if (fDepth == 0) {
fDepth= 1;
if (forward) {
switch (ch) {
case LBRACE:
fOpening= LBRACE;
fClosing= RBRACE;
break;
case LPAREN:
fOpening= LPAREN;
fClosing= RPAREN;
break;
case LBRACKET:
fOpening= LBRACKET;
fClosing= RBRACKET;
break;
}
} else {
switch (ch) {
case RBRACE:
fOpening= RBRACE;
fClosing= LBRACE;
break;
case RPAREN:
fOpening= RPAREN;
fClosing= LPAREN;
break;
case RBRACKET:
fOpening= RBRACKET;
fClosing= LBRACKET;
break;
}
}
}
return false;
}
}
/** The document being scanned. */
private IDocument fDocument;
/** The partitioning being used for scanning. */
private String fPartitioning;
/** The partition to scan in. */
private String fPartition;
/* internal scan state */
/** the most recently read character. */
private char fChar;
/** the most recently read position. */
private int fPos;
/* preset stop conditions */
private final StopCondition fNonWSDefaultPart= new NonWhitespaceDefaultPartition();
private final static StopCondition fNonWS= new NonWhitespace();
private final StopCondition fNonIdent= new NonRubyIdentifierPartDefaultPartition();
/**
* Creates a new instance.
*
* @param document the document to scan
* @param partitioning the partitioning to use for scanning
* @param partition the partition to scan in
*/
public RubyHeuristicScanner(IDocument document, String partitioning, String partition) {
Assert.isNotNull(document);
Assert.isNotNull(partitioning);
Assert.isNotNull(partition);
fDocument= document;
fPartitioning= partitioning;
fPartition= partition;
}
/**
* Calls <code>this(document, IRubyPartitions.RUBY_PARTITIONING, IDocument.DEFAULT_CONTENT_TYPE)</code>.
*
* @param document the document to scan.
*/
public RubyHeuristicScanner(IDocument document) {
this(document, IRubyPartitions.RUBY_PARTITIONING, IDocument.DEFAULT_CONTENT_TYPE);
}
/**
* Returns the most recent internal scan position.
*
* @return the most recent internal scan position.
*/
public int getPosition() {
return fPos;
}
/**
* Returns the next token in forward direction, starting at <code>start</code>, and not extending
* further than <code>bound</code>. The return value is one of the constants defined in {@link Symbols}.
* After a call, {@link #getPosition()} will return the position just after the scanned token
* (i.e. the next position that will be scanned).
*
* @param start the first character position in the document to consider
* @param bound the first position not to consider any more
* @return a constant from {@link Symbols} describing the next token
*/
public int nextToken(int start, int bound) {
int pos= scanForward(start, bound, fNonWSDefaultPart);
if (pos == NOT_FOUND)
return TokenEOF;
fPos++;
switch (fChar) {
case LBRACE:
return TokenLBRACE;
case RBRACE:
return TokenRBRACE;
case LBRACKET:
return TokenLBRACKET;
case RBRACKET:
return TokenRBRACKET;
case LPAREN:
return TokenLPAREN;
case RPAREN:
return TokenRPAREN;
case SEMICOLON:
return TokenSEMICOLON;
case COMMA:
return TokenCOMMA;
case QUESTIONMARK:
return TokenQUESTIONMARK;
case EQUAL:
return TokenEQUAL;
}
// else
if (Character.isJavaIdentifierPart(fChar)) {
// assume an ident or keyword
int from= pos, to;
pos= scanForward(pos + 1, bound, fNonIdent);
if (pos == NOT_FOUND)
to= bound == UNBOUND ? fDocument.getLength() : bound;
else
to= pos;
String identOrKeyword;
try {
identOrKeyword= fDocument.get(from, to - from);
} catch (BadLocationException e) {
return TokenEOF;
}
return getToken(identOrKeyword);
}
// operators, number literals etc
return TokenOTHER;
}
/**
* Returns the next token in backward direction, starting at <code>start</code>, and not extending
* further than <code>bound</code>. The return value is one of the constants defined in {@link Symbols}.
* After a call, {@link #getPosition()} will return the position just before the scanned token
* starts (i.e. the next position that will be scanned).
*
* @param start the first character position in the document to consider
* @param bound the first position not to consider any more
* @return a constant from {@link Symbols} describing the previous token
*/
public int previousToken(int start, int bound) {
int pos= scanBackward(start, bound, fNonWSDefaultPart);
if (pos == NOT_FOUND)
return TokenEOF;
fPos--;
switch (fChar) {
case LBRACE:
return TokenLBRACE;
case RBRACE:
return TokenRBRACE;
case LBRACKET:
return TokenLBRACKET;
case RBRACKET:
return TokenRBRACKET;
case LPAREN:
return TokenLPAREN;
case RPAREN:
return TokenRPAREN;
case SEMICOLON:
return TokenSEMICOLON;
case COLON:
return TokenCOLON;
case COMMA:
return TokenCOMMA;
case QUESTIONMARK:
return TokenQUESTIONMARK;
case EQUAL:
return TokenEQUAL;
}
// else
// FIXME Change calls to isJavaIdentifierPart to a custom method that does isRubyidentifierPart
if (Character.isJavaIdentifierPart(fChar)) {
// assume an ident or keyword
int from, to= pos + 1;
pos= scanBackward(pos - 1, bound, fNonIdent);
if (pos == NOT_FOUND)
from= bound == UNBOUND ? 0 : bound + 1;
else
from= pos + 1;
String identOrKeyword;
try {
identOrKeyword= fDocument.get(from, to - from);
} catch (BadLocationException e) {
return TokenEOF;
}
return getToken(identOrKeyword);
}
// operators, number literals etc
return TokenOTHER;
}
/**
* Returns one of the keyword constants or <code>TokenIDENT</code> for a scanned identifier.
*
* @param s a scanned identifier
* @return one of the constants defined in {@link Symbols}
*/
private int getToken(String s) {
Assert.isNotNull(s);
switch (s.length()) {
case 2:
if ("if".equals(s)) //$NON-NLS-1$
return TokenIF;
if ("in".equals(s)) //$NON-NLS-1$
return TokenIN;
if ("do".equals(s)) //$NON-NLS-1$
return TokenDO;
if ("or".equals(s)) //$NON-NLS-1$
return TokenOR;
break;
case 3:
if ("end".equals(s)) //$NON-NLS-1$
return TokenEND;
if ("END".equals(s)) //$NON-NLS-1$
return TokenBIGEND;
if ("def".equals(s)) //$NON-NLS-1$
return TokenDEF;
if ("for".equals(s)) //$NON-NLS-1$
return TokenFOR;
if ("nil".equals(s)) //$NON-NLS-1$
return TokenNIL;
if ("and".equals(s)) //$NON-NLS-1$
return TokenAND;
if ("not".equals(s)) //$NON-NLS-1$
return TokenNOT;
break;
case 4:
if ("self".equals(s)) //$NON-NLS-1$
return TokenSELF;
if ("true".equals(s)) //$NON-NLS-1$
return TokenTRUE;
if ("case".equals(s)) //$NON-NLS-1$
return TokenCASE;
if ("else".equals(s)) //$NON-NLS-1$
return TokenELSE;
if ("then".equals(s)) //$NON-NLS-1$
return TokenTHEN;
if ("when".equals(s)) //$NON-NLS-1$
return TokenWHEN;
if ("next".equals(s)) //$NON-NLS-1$
return TokenNEXT;
if ("redo".equals(s)) //$NON-NLS-1$
return TokenREDO;
break;
case 5:
if ("break".equals(s)) //$NON-NLS-1$
return TokenBREAK;
if ("alias".equals(s)) //$NON-NLS-1$
return TokenALIAS;
if ("class".equals(s)) //$NON-NLS-1$
return TokenCLASS;
if ("while".equals(s)) //$NON-NLS-1$
return TokenWHILE;
if ("undef".equals(s)) //$NON-NLS-1$
return TokenUNDEF;
if ("begin".equals(s)) //$NON-NLS-1$
return TokenBEGIN;
if ("BEGIN".equals(s)) //$NON-NLS-1$
return TokenBIGBEGIN;
if ("retry".equals(s)) //$NON-NLS-1$
return TokenRETRY;
if ("yield".equals(s)) //$NON-NLS-1$
return TokenYIELD;
if ("super".equals(s)) //$NON-NLS-1$
return TokenSUPER;
if ("false".equals(s)) //$NON-NLS-1$
return TokenFALSE;
if ("until".equals(s)) //$NON-NLS-1$
return TokenUNTIL;
if ("elsif".equals(s)) //$NON-NLS-1$
return TokenELSIF;
break;
case 6:
if ("return".equals(s)) //$NON-NLS-1$
return TokenRETURN;
if ("module".equals(s)) //$NON-NLS-1$
return TokenMODULE;
if ("unless".equals(s)) //$NON-NLS-1$
return TokenUNLESS;
if ("rescue".equals(s)) //$NON-NLS-1$
return TokenRESCUE;
if ("ensure".equals(s)) //$NON-NLS-1$
return TokenENSURE;
break;
case 7:
if ("defined".equals(s)) //$NON-NLS-1$
return TokenDEFINED;
break;
case 8:
if ("__LINE__".equals(s)) //$NON-NLS-1$
return TokenLINE;
if ("__FILE__".equals(s)) //$NON-NLS-1$
return TokenFILE;
break;
}
return TokenIDENT;
}
/**
* Returns the position of the closing peer character (forward search). Any scopes introduced by opening peers
* are skipped. All peers accounted for must reside in the default partition.
*
* <p>Note that <code>start</code> must not point to the opening peer, but to the first
* character being searched.</p>
*
* @param start the start position
* @param openingPeer the opening peer character (e.g. '{')
* @param closingPeer the closing peer character (e.g. '}')
* @return the matching peer character position, or <code>NOT_FOUND</code>
*/
public int findClosingPeer(int start, final char openingPeer, final char closingPeer) {
Assert.isNotNull(fDocument);
Assert.isTrue(start >= 0);
try {
int depth= 1;
start -= 1;
while (true) {
start= scanForward(start + 1, UNBOUND, new CharacterMatch(new char[] {openingPeer, closingPeer}));
if (start == NOT_FOUND)
return NOT_FOUND;
if (fDocument.getChar(start) == openingPeer)
depth++;
else
depth--;
if (depth == 0)
return start;
}
} catch (BadLocationException e) {
return NOT_FOUND;
}
}
/**
* Returns the position of the opening peer character (backward search). Any scopes introduced by closing peers
* are skipped. All peers accounted for must reside in the default partition.
*
* <p>Note that <code>start</code> must not point to the closing peer, but to the first
* character being searched.</p>
*
* @param start the start position
* @param openingPeer the opening peer character (e.g. '{')
* @param closingPeer the closing peer character (e.g. '}')
* @return the matching peer character position, or <code>NOT_FOUND</code>
*/
public int findOpeningPeer(int start, char openingPeer, char closingPeer) {
Assert.isTrue(start < fDocument.getLength());
try {
int depth= 1;
start += 1;
while (true) {
start= scanBackward(start - 1, UNBOUND, new CharacterMatch(new char[] {openingPeer, closingPeer}));
if (start == NOT_FOUND)
return NOT_FOUND;
if (fDocument.getChar(start) == closingPeer)
depth++;
else
depth--;
if (depth == 0)
return start;
}
} catch (BadLocationException e) {
return NOT_FOUND;
}
}
/**
* Computes the surrounding block around <code>offset</code>. The search is started at the
* beginning of <code>offset</code>, i.e. an opening brace at <code>offset</code> will not be
* part of the surrounding block, but a closing brace will.
*
* @param offset the offset for which the surrounding block is computed
* @return a region describing the surrounding block, or <code>null</code> if none can be found
*/
public IRegion findSurroundingBlock(int offset) {
if (offset < 1 || offset >= fDocument.getLength())
return null;
int begin= findOpeningPeer(offset - 1, LBRACE, RBRACE);
int end= findClosingPeer(offset, LBRACE, RBRACE);
if (begin == NOT_FOUND || end == NOT_FOUND)
return null;
return new Region(begin, end + 1 - begin);
}
/**
* Finds the smallest position in <code>fDocument</code> such that the position is >= <code>position</code>
* and < <code>bound</code> and <code>Character.isWhitespace(fDocument.getChar(pos))</code> evaluates to <code>false</code>
* and the position is in the default partition.
*
* @param position the first character position in <code>fDocument</code> to be considered
* @param bound the first position in <code>fDocument</code> to not consider any more, with <code>bound</code> > <code>position</code>, or <code>UNBOUND</code>
* @return the smallest position of a non-whitespace character in [<code>position</code>, <code>bound</code>) that resides in a Ruby partition, or <code>NOT_FOUND</code> if none can be found
*/
public int findNonWhitespaceForward(int position, int bound) {
return scanForward(position, bound, fNonWSDefaultPart);
}
/**
* Finds the smallest position in <code>fDocument</code> such that the position is >= <code>position</code>
* and < <code>bound</code> and <code>Character.isWhitespace(fDocument.getChar(pos))</code> evaluates to <code>false</code>.
*
* @param position the first character position in <code>fDocument</code> to be considered
* @param bound the first position in <code>fDocument</code> to not consider any more, with <code>bound</code> > <code>position</code>, or <code>UNBOUND</code>
* @return the smallest position of a non-whitespace character in [<code>position</code>, <code>bound</code>), or <code>NOT_FOUND</code> if none can be found
*/
public int findNonWhitespaceForwardInAnyPartition(int position, int bound) {
return scanForward(position, bound, fNonWS);
}
/**
* Finds the highest position in <code>fDocument</code> such that the position is <= <code>position</code>
* and > <code>bound</code> and <code>Character.isWhitespace(fDocument.getChar(pos))</code> evaluates to <code>false</code>
* and the position is in the default partition.
*
* @param position the first character position in <code>fDocument</code> to be considered
* @param bound the first position in <code>fDocument</code> to not consider any more, with <code>bound</code> < <code>position</code>, or <code>UNBOUND</code>
* @return the highest position of a non-whitespace character in (<code>bound</code>, <code>position</code>] that resides in a Ruby partition, or <code>NOT_FOUND</code> if none can be found
*/
public int findNonWhitespaceBackward(int position, int bound) {
return scanBackward(position, bound, fNonWSDefaultPart);
}
/**
* Finds the lowest position <code>p</code> in <code>fDocument</code> such that <code>start</code> <= p <
* <code>bound</code> and <code>condition.stop(fDocument.getChar(p), p)</code> evaluates to <code>true</code>.
*
* @param start the first character position in <code>fDocument</code> to be considered
* @param bound the first position in <code>fDocument</code> to not consider any more, with <code>bound</code> > <code>start</code>, or <code>UNBOUND</code>
* @param condition the <code>StopCondition</code> to check
* @return the lowest position in [<code>start</code>, <code>bound</code>) for which <code>condition</code> holds, or <code>NOT_FOUND</code> if none can be found
*/
public int scanForward(int start, int bound, StopCondition condition) {
Assert.isTrue(start >= 0);
if (bound == UNBOUND)
bound= fDocument.getLength();
Assert.isTrue(bound <= fDocument.getLength());
try {
fPos= start;
while (fPos < bound) {
fChar= fDocument.getChar(fPos);
if (condition.stop(fChar, fPos, true))
return fPos;
fPos++;
}
} catch (BadLocationException e) {
}
return NOT_FOUND;
}
/**
* Finds the lowest position in <code>fDocument</code> such that the position is >= <code>position</code>
* and < <code>bound</code> and <code>fDocument.getChar(position) == ch</code> evaluates to <code>true</code>
* and the position is in the default partition.
*
* @param position the first character position in <code>fDocument</code> to be considered
* @param bound the first position in <code>fDocument</code> to not consider any more, with <code>bound</code> > <code>position</code>, or <code>UNBOUND</code>
* @param ch the <code>char</code> to search for
* @return the lowest position of <code>ch</code> in (<code>bound</code>, <code>position</code>] that resides in a Ruby partition, or <code>NOT_FOUND</code> if none can be found
*/
public int scanForward(int position, int bound, char ch) {
return scanForward(position, bound, new CharacterMatch(ch));
}
/**
* Finds the lowest position in <code>fDocument</code> such that the position is >= <code>position</code>
* and < <code>bound</code> and <code>fDocument.getChar(position) == ch</code> evaluates to <code>true</code> for at least one
* ch in <code>chars</code> and the position is in the default partition.
*
* @param position the first character position in <code>fDocument</code> to be considered
* @param bound the first position in <code>fDocument</code> to not consider any more, with <code>bound</code> > <code>position</code>, or <code>UNBOUND</code>
* @param chars an array of <code>char</code> to search for
* @return the lowest position of a non-whitespace character in [<code>position</code>, <code>bound</code>) that resides in a Ruby partition, or <code>NOT_FOUND</code> if none can be found
*/
public int scanForward(int position, int bound, char[] chars) {
return scanForward(position, bound, new CharacterMatch(chars));
}
/**
* Finds the highest position <code>p</code> in <code>fDocument</code> such that <code>bound</code> < <code>p</code> <= <code>start</code>
* and <code>condition.stop(fDocument.getChar(p), p)</code> evaluates to <code>true</code>.
*
* @param start the first character position in <code>fDocument</code> to be considered
* @param bound the first position in <code>fDocument</code> to not consider any more, with <code>bound</code> < <code>start</code>, or <code>UNBOUND</code>
* @param condition the <code>StopCondition</code> to check
* @return the highest position in (<code>bound</code>, <code>start</code> for which <code>condition</code> holds, or <code>NOT_FOUND</code> if none can be found
*/
public int scanBackward(int start, int bound, StopCondition condition) {
if (bound == UNBOUND)
bound= -1;
Assert.isTrue(bound >= -1);
Assert.isTrue(start < fDocument.getLength() );
try {
fPos= start;
while (fPos > bound) {
fChar= fDocument.getChar(fPos);
if (condition.stop(fChar, fPos, false))
return fPos;
fPos--;
}
} catch (BadLocationException e) {
}
return NOT_FOUND;
}
/**
* Finds the highest position in <code>fDocument</code> such that the position is <= <code>position</code>
* and > <code>bound</code> and <code>fDocument.getChar(position) == ch</code> evaluates to <code>true</code> for at least one
* ch in <code>chars</code> and the position is in the default partition.
*
* @param position the first character position in <code>fDocument</code> to be considered
* @param bound the first position in <code>fDocument</code> to not consider any more, with <code>bound</code> < <code>position</code>, or <code>UNBOUND</code>
* @param ch the <code>char</code> to search for
* @return the highest position of one element in <code>chars</code> in (<code>bound</code>, <code>position</code>] that resides in a Ruby partition, or <code>NOT_FOUND</code> if none can be found
*/
public int scanBackward(int position, int bound, char ch) {
return scanBackward(position, bound, new CharacterMatch(ch));
}
/**
* Finds the highest position in <code>fDocument</code> such that the position is <= <code>position</code>
* and > <code>bound</code> and <code>fDocument.getChar(position) == ch</code> evaluates to <code>true</code> for at least one
* ch in <code>chars</code> and the position is in the default partition.
*
* @param position the first character position in <code>fDocument</code> to be considered
* @param bound the first position in <code>fDocument</code> to not consider any more, with <code>bound</code> < <code>position</code>, or <code>UNBOUND</code>
* @param chars an array of <code>char</code> to search for
* @return the highest position of one element in <code>chars</code> in (<code>bound</code>, <code>position</code>] that resides in a Ruby partition, or <code>NOT_FOUND</code> if none can be found
*/
public int scanBackward(int position, int bound, char[] chars) {
return scanBackward(position, bound, new CharacterMatch(chars));
}
/**
* Checks whether <code>position</code> resides in a default (Ruby) partition of <code>fDocument</code>.
*
* @param position the position to be checked
* @return <code>true</code> if <code>position</code> is in the default partition of <code>fDocument</code>, <code>false</code> otherwise
*/
public boolean isDefaultPartition(int position) {
Assert.isTrue(position >= 0);
Assert.isTrue(position <= fDocument.getLength());
try {
ITypedRegion region= TextUtilities.getPartition(fDocument, fPartitioning, position, false);
return region.getType().equals(fPartition);
} catch (BadLocationException e) {
}
return false;
}
/**
* Checks if the line seems to be an open condition not followed by a block (i.e. an if, while,
* or for statement with just one following statement, see example below).
*
* <pre>
* if (condition)
* doStuff();
* </pre>
*
* <p>Algorithm: if the last non-WS, non-Comment code on the line is an if (condition), while (condition),
* for( expression), do, else, and there is no statement after that </p>
*
* @param position the insert position of the new character
* @param bound the lowest position to consider
* @return <code>true</code> if the code is a conditional statement or loop without a block, <code>false</code> otherwise
*/
public boolean isBracelessBlockStart(int position, int bound) {
if (position < 1)
return false;
switch (previousToken(position, bound)) {
case TokenDO:
case TokenELSE:
return true;
case TokenRPAREN:
position= findOpeningPeer(fPos, LPAREN, RPAREN);
if (position > 0) {
switch (previousToken(position - 1, bound)) {
case TokenIF:
case TokenFOR:
case TokenWHILE:
return true;
}
}
}
return false;
}
}