/*******************************************************************************
* Copyright (c) 2006 Business Objects Software Limited and others.
* All rights reserved.
* This file is made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Business Objects Software Limited - initial API and implementation based on Eclipse 3.1.2 code for
* /org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/JavaHeuristicScanner.java
* Eclipse source is available at: http://www.eclipse.org/downloads/
*******************************************************************************/
/*
* CALHeuristicScanner.java
* Creation date: Feb 8, 2006.
* By: Edward Lam
*/
package org.openquark.cal.eclipse.ui.text;
import java.util.Arrays;
import org.eclipse.core.runtime.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;
import org.eclipse.jface.text.TypedRegion;
import org.openquark.cal.compiler.LanguageInfo;
/**
* Utility methods for heuristic based Java manipulations in an incomplete CAL source file.
*
* <p>An instance holds some internal position in the document and is therefore not threadsafe.</p>
*
* @author Edward Lam
*/
public final class CALHeuristicScanner {
/**
* 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 PERIOD = '.';
private static final char LBRACKET = '[';
private static final char RBRACKET = ']';
private static final char QUESTIONMARK = '?';
private static final char EQUAL = '=';
private static final char LANGLE = '<';
private static final char RANGLE = '>';
private static final char DASH = '-';
private static final char BAR = '|';
private static final char BACKSLASH = '\\';
/**
* 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.
*/
private static abstract class 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.
*/
public abstract boolean stop(char ch, int position, boolean forward);
/**
* Asks the condition to return the next position to query. The default is to return the next/previous position.
*
* @return the next position to scan
*/
public int nextPosition(int position, boolean forward) {
return forward ? position + 1 : position - 1;
}
}
/**
* Stops upon a non-whitespace (as defined by {@link LanguageInfo#isCALWhitespace(char)}) character.
*/
private static class NonWhitespace extends StopCondition {
/*
* @see org.eclipse.jdt.internal.ui.text.JavaHeuristicScanner.StopCondition#stop(char)
*/
@Override
public boolean stop(char ch, int position, boolean forward) {
return !LanguageInfo.isCALWhitespace(ch);
}
}
/**
* Stops upon a non-whitespace character in the default partition.
*
* @see CALHeuristicScanner.NonWhitespace
*/
private final class NonWhitespaceDefaultPartition extends NonWhitespace {
/*
* @see org.eclipse.jdt.internal.ui.text.JavaHeuristicScanner.StopCondition#stop(char)
*/
@Override
public boolean stop(char ch, int position, boolean forward) {
return super.stop(ch, position, true) && isDefaultPartition(position);
}
/*
* @see org.eclipse.jdt.internal.ui.text.JavaHeuristicScanner.StopCondition#nextPosition(int, boolean)
*/
@Override
public int nextPosition(int position, boolean forward) {
ITypedRegion partition = getPartition(position);
if (fPartition.equals(partition.getType())) {
return super.nextPosition(position, forward);
}
if (forward) {
int end = partition.getOffset() + partition.getLength();
if (position < end) {
return end;
}
} else {
int offset = partition.getOffset();
if (position > offset) {
return offset - 1;
}
}
return super.nextPosition(position, forward);
}
}
/**
* Stops upon a non-cal identifier (as defined by {@link LanguageInfo#isCALVarPart(char)}) character.
*/
private static class NonCALIdentifierPart extends StopCondition {
/*
* @see org.eclipse.jdt.internal.ui.text.JavaHeuristicScanner.StopCondition#stop(char)
*/
@Override
public boolean stop(char ch, int position, boolean forward) {
return !LanguageInfo.isCALVarPart(ch);
}
}
/**
* Stops upon a non-java identifier character in the default partition.
*
* @see CALHeuristicScanner.NonCALIdentifierPart
*/
private final class NonCALIdentifierPartDefaultPartition extends NonCALIdentifierPart {
/*
* @see org.eclipse.jdt.internal.ui.text.JavaHeuristicScanner.StopCondition#stop(char)
*/
@Override
public boolean stop(char ch, int position, boolean forward) {
return super.stop(ch, position, true) || !isDefaultPartition(position);
}
/*
* @see org.eclipse.jdt.internal.ui.text.JavaHeuristicScanner.StopCondition#nextPosition(int, boolean)
*/
@Override
public int nextPosition(int position, boolean forward) {
ITypedRegion partition = getPartition(position);
if (fPartition.equals(partition.getType())) {
return super.nextPosition(position, forward);
}
if (forward) {
int end = partition.getOffset() + partition.getLength();
if (position < end) {
return end;
}
} else {
int offset = partition.getOffset();
if (position > offset) {
return offset - 1;
}
}
return super.nextPosition(position, forward);
}
}
/**
* Stops upon a character in the default partition that matches the given character list.
*/
private final class CharacterMatch extends 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.JavaHeuristicScanner.StopCondition#stop(char, int)
*/
@Override
public boolean stop(char ch, int position, boolean forward) {
return Arrays.binarySearch(fChars, ch) >= 0 && isDefaultPartition(position);
}
/*
* @see org.eclipse.jdt.internal.ui.text.JavaHeuristicScanner.StopCondition#nextPosition(int, boolean)
*/
@Override
public int nextPosition(int position, boolean forward) {
ITypedRegion partition = getPartition(position);
if (fPartition.equals(partition.getType())) {
return super.nextPosition(position, forward);
}
if (forward) {
int end = partition.getOffset() + partition.getLength();
if (position < end) {
return end;
}
} else {
int offset = partition.getOffset();
if (position > offset) {
return offset - 1;
}
}
return super.nextPosition(position, forward);
}
}
/** The document being scanned. */
private final IDocument fDocument;
/** The partitioning being used for scanning. */
private final String fPartitioning;
/** The partition to scan in. */
private final 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 NonCALIdentifierPartDefaultPartition();
/**
* 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 CALHeuristicScanner(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, IJavaPartitions.JAVA_PARTITIONING, IDocument.DEFAULT_CONTENT_TYPE)</code>.
*
* @param document the document to scan.
*/
public CALHeuristicScanner(IDocument document) {
this(document, CALPartitions.CAL_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 Symbols.TokenEOF;
}
fPos++;
switch (fChar) {
case LBRACE:
return Symbols.TokenLBRACE;
case RBRACE:
return Symbols.TokenRBRACE;
case LBRACKET:
return Symbols.TokenLBRACKET;
case RBRACKET:
return Symbols.TokenRBRACKET;
case LPAREN:
return Symbols.TokenLPAREN;
case RPAREN:
return Symbols.TokenRPAREN;
case COLON:
return Symbols.TokenCOLON;
case SEMICOLON:
return Symbols.TokenSEMICOLON;
case COMMA:
return Symbols.TokenCOMMA;
case PERIOD:
return Symbols.TokenPERIOD;
case QUESTIONMARK:
return Symbols.TokenQUESTIONMARK;
case EQUAL:
return Symbols.TokenEQUAL;
case LANGLE:
return Symbols.TokenLESSTHAN;
case RANGLE:
return Symbols.TokenGREATERTHAN;
case DASH:
return Symbols.TokenDASH;
case BAR:
return Symbols.TokenBAR;
case BACKSLASH:
return Symbols.TokenBACKSLASH;
}
// else
if (LanguageInfo.isCALVarPart(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 Symbols.TokenEOF;
}
return getToken(identOrKeyword);
} else {
// operators, number literals etc
return Symbols.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 Symbols.TokenEOF;
}
fPos--;
switch (fChar) {
case LBRACE:
return Symbols.TokenLBRACE;
case RBRACE:
return Symbols.TokenRBRACE;
case LBRACKET:
return Symbols.TokenLBRACKET;
case RBRACKET:
return Symbols.TokenRBRACKET;
case LPAREN:
return Symbols.TokenLPAREN;
case RPAREN:
return Symbols.TokenRPAREN;
case SEMICOLON:
return Symbols.TokenSEMICOLON;
case COLON:
return Symbols.TokenCOLON;
case COMMA:
return Symbols.TokenCOMMA;
case PERIOD:
return Symbols.TokenPERIOD;
case QUESTIONMARK:
return Symbols.TokenQUESTIONMARK;
case EQUAL:
return Symbols.TokenEQUAL;
case LANGLE:
return Symbols.TokenLESSTHAN;
case RANGLE:
return Symbols.TokenGREATERTHAN;
case DASH:
return Symbols.TokenDASH;
case BAR:
return Symbols.TokenBAR;
case BACKSLASH:
return Symbols.TokenBACKSLASH;
}
// else
if (LanguageInfo.isCALVarPart(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 Symbols.TokenEOF;
}
return getToken(identOrKeyword);
} else {
// operators, number literals etc
return Symbols.TokenOTHER;
}
}
/**
* Returns one of the keyword constants or <code>TokenCONSIDENT</code> or <code>TokenVARIDENT</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 ("in".equals(s)) {
return Symbols.TokenIN;
}
if ("of".equals(s)) {
return Symbols.TokenOF;
}
if ("if".equals(s)) {
return Symbols.TokenIF;
}
// if ("do".equals(s)) //$NON-NLS-1$
// return Symbols.TokenDO;
break;
case 3:
if ("let".equals(s)) {
return Symbols.TokenLET;
}
if ("jvm".equals(s)) {
return Symbols.TokenJVM;
}
// if ("for".equals(s)) //$NON-NLS-1$
// return Symbols.TokenFOR;
// if ("try".equals(s)) //$NON-NLS-1$
// return Symbols.TokenTRY;
// if ("new".equals(s)) //$NON-NLS-1$
// return Symbols.TokenNEW;
break;
case 4:
if ("case".equals(s)) {
return Symbols.TokenCASE;
}
if ("else".equals(s)) {
return Symbols.TokenELSE;
}
if ("data".equals(s)) {
return Symbols.TokenDATA;
}
if ("then".equals(s)) {
return Symbols.TokenTHEN;
}
// if ("enum".equals(s)) //$NON-NLS-1$
// return Symbols.TokenENUM;
// if ("goto".equals(s)) //$NON-NLS-1$
// return Symbols.TokenGOTO;
break;
case 5:
// if ("break".equals(s)) //$NON-NLS-1$
// return Symbols.TokenBREAK;
// if ("catch".equals(s)) //$NON-NLS-1$
// return Symbols.TokenCATCH;
if ("class".equals(s)) {
return Symbols.TokenCLASS;
}
if ("where".equals(s)) {
return Symbols.TokenWHERE;
}
if ("using".equals(s)) {
return Symbols.TokenUSING;
}
// if ("while".equals(s)) //$NON-NLS-1$
// return Symbols.TokenWHILE;
break;
case 6:
if ("public".equals(s)) {
return Symbols.TokenPUBLIC;
}
if ("import".equals(s)) {
return Symbols.TokenIMPORT;
}
if ("unsafe".equals(s)) {
return Symbols.TokenUNSAFE;
}
if ("module".equals(s)) {
return Symbols.TokenMODULE;
}
if ("friend".equals(s)) {
return Symbols.TokenFRIEND;
}
// if ("return".equals(s)) //$NON-NLS-1$
// return Symbols.TokenRETURN;
// if ("static".equals(s)) //$NON-NLS-1$
// return Symbols.TokenSTATIC;
// if ("switch".equals(s)) //$NON-NLS-1$
// return Symbols.TokenSWITCH;
break;
case 7:
if ("private".equals(s)) {
return Symbols.TokenPRIVATE;
}
if ("foreign".equals(s)) {
return Symbols.TokenFOREIGN;
}
if ("default".equals(s)) {
return Symbols.TokenDEFAULT;
}
// if ("finally".equals(s)) //$NON-NLS-1$
// return Symbols.TokenFINALLY;
break;
case 8:
if ("instance".equals(s)) {
return Symbols.TokenINSTANCE;
}
if ("deriving".equals(s)) {
return Symbols.TokenDERIVING;
}
if ("function".equals(s)) {
return Symbols.TokenFUNCTION;
}
case 9:
if ("protected".equals(s)) {
return Symbols.TokenPROTECTED;
}
if ("primitive".equals(s)) {
return Symbols.TokenPRIMITIVE;
}
if ("typeClass".equals(s)) {
return Symbols.TokenTYPECLASS;
}
// if ("interface".equals(s)) //$NON-NLS-1$
// return Symbols.TokenINTERFACE;
break;
// case 12:
// if ("synchronized".equals(s)) //$NON-NLS-1$
// return Symbols.TokenSYNCHRONIZED;
// break;
case 15:
if ("dataConstructor".equals(s)) {
return Symbols.TokenDATACONSTRUCTOR;
}
if ("typeConstructor".equals(s)) {
return Symbols.TokenTYPECONSTRUCTOR;
}
}
if (s.length() > 0 && LanguageInfo.isCALConsStart(s.charAt(0))) {
return Symbols.TokenCONSIDENT;
}
return Symbols.TokenOTHERIDENT;
}
/**
* 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>LanguageInfo.isCALWhitespace(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 Java 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>LanguageInfo.isCALWhitespace(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>LanguageInfo.isCALWhitespace(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 Java 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 = condition.nextPosition(fPos, true);
}
} 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 Java 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 Java 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 = condition.nextPosition(fPos, false);
}
} 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 Java 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 Java 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 (CAL) 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 {
return fPartition.equals(TextUtilities.getContentType(fDocument, fPartitioning, position, false));
} catch (BadLocationException e) {
return false;
}
}
/**
* Returns the partition at <code>position</code>.
*
* @param position the position to get the partition for
* @return the partition at <code>position</code> or a dummy zero-length
* partition if accessing the document fails
*/
private ITypedRegion getPartition(int position) {
Assert.isTrue(position >= 0);
Assert.isTrue(position <= fDocument.getLength());
try {
return TextUtilities.getPartition(fDocument, fPartitioning, position, false);
} catch (BadLocationException e) {
return new TypedRegion(position, 0, "__no_partition_at_all"); //$NON-NLS-1$
}
}
/**
* 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 Symbols.TokenDO:
case Symbols.TokenELSE:
return true;
case Symbols.TokenRPAREN:
position= findOpeningPeer(fPos, LPAREN, RPAREN);
if (position > 0) {
switch (previousToken(position - 1, bound)) {
case Symbols.TokenIF:
case Symbols.TokenFOR:
case Symbols.TokenWHILE:
return true;
}
}
}
return false;
}
}