/******************************************************************************* * 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 net.sourceforge.phpdt.internal.ui.text; import java.util.Arrays; import net.sourceforge.phpdt.internal.compiler.parser.Scanner; 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 Java manipulations in an incomplete Java source file. * *
An instance holds some internal position in the document and is therefore not threadsafe.
* * @since 3.0 */ public class JavaHeuristicScanner 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 *fDocument.getLength()
(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 scanXXX
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 true
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 net.sourceforge.phpdt.internal.ui.text.JavaHeuristicScanner.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 net.sourceforge.phpdt.internal.ui.text.JavaHeuristicScanner.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 Scanner#isPHPIdentifierPart(char)}) character.
*/
private static class NonJavaIdentifierPart implements StopCondition {
/*
* @see net.sourceforge.phpdt.internal.ui.text.JavaHeuristicScanner.StopCondition#stop(char)
*/
public boolean stop(char ch, int position, boolean forward) {
return !Scanner.isPHPIdentifierPart(ch);
}
}
/**
* Stops upon a non-java identifier character in the default partition.
*
* @see NonJavaIdentifierPart
*/
private class NonJavaIdentifierPartDefaultPartition extends NonJavaIdentifierPart {
/*
* @see net.sourceforge.phpdt.internal.ui.text.JavaHeuristicScanner.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 net.sourceforge.phpdt.internal.ui.text.JavaHeuristicScanner.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 net.sourceforge.phpdt.internal.ui.text.JavaHeuristicScanner.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 NonJavaIdentifierPartDefaultPartition();
/**
* 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 JavaHeuristicScanner(IDocument document, String partitioning, String partition) {
Assert.isNotNull(document);
Assert.isNotNull(partitioning);
Assert.isNotNull(partition);
fDocument= document;
fPartitioning= partitioning;
fPartition= partition;
}
/**
* Calls this(document, IJavaPartitions.JAVA_PARTITIONING, IDocument.DEFAULT_CONTENT_TYPE)
.
*
* @param document the document to scan.
*/
public JavaHeuristicScanner(IDocument document) {
this(document, IPHPPartitions.PHP_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 start
, and not extending
* further than bound
. 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 (Scanner.isPHPIdentifierPart(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);
} else {
// operators, number literals etc
return TokenOTHER;
}
}
/**
* Returns the next token in backward direction, starting at start
, and not extending
* further than bound
. 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
if (Scanner.isPHPIdentifierPart(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);
} else {
// operators, number literals etc
return TokenOTHER;
}
}
/**
* Returns one of the keyword constants or TokenIDENT
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 ("do".equals(s)) //$NON-NLS-1$
return TokenDO;
break;
case 3:
if ("for".equals(s)) //$NON-NLS-1$
return TokenFOR;
if ("try".equals(s)) //$NON-NLS-1$
return TokenTRY;
if ("new".equals(s)) //$NON-NLS-1$
return TokenNEW;
break;
case 4:
if ("case".equals(s)) //$NON-NLS-1$
return TokenCASE;
if ("else".equals(s)) //$NON-NLS-1$
return TokenELSE;
if ("goto".equals(s)) //$NON-NLS-1$
return TokenGOTO;
break;
case 5:
if ("break".equals(s)) //$NON-NLS-1$
return TokenBREAK;
if ("catch".equals(s)) //$NON-NLS-1$
return TokenCATCH;
if ("while".equals(s)) //$NON-NLS-1$
return TokenWHILE;
break;
case 6:
if ("return".equals(s)) //$NON-NLS-1$
return TokenRETURN;
if ("static".equals(s)) //$NON-NLS-1$
return TokenSTATIC;
if ("switch".equals(s)) //$NON-NLS-1$
return TokenSWITCH;
break;
case 7:
if ("default".equals(s)) //$NON-NLS-1$
return TokenDEFAULT;
if ("finally".equals(s)) //$NON-NLS-1$
return TokenFINALLY;
break;
case 12:
if ("synchronized".equals(s)) //$NON-NLS-1$
return TokenSYNCHRONIZED;
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.
*
* Note that start
must not point to the opening peer, but to the first
* character being searched.
NOT_FOUND
*/
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.
*
* Note that start
must not point to the closing peer, but to the first
* character being searched.
NOT_FOUND
*/
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 offset
. The search is started at the
* beginning of offset
, i.e. an opening brace at offset
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 null
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 fDocument
such that the position is >= position
* and < bound
and Character.isWhitespace(fDocument.getChar(pos))
evaluates to false
* and the position is in the default partition.
*
* @param position the first character position in fDocument
to be considered
* @param bound the first position in fDocument
to not consider any more, with bound
> position
, or UNBOUND
* @return the smallest position of a non-whitespace character in [position
, bound
) that resides in a Java partition, or NOT_FOUND
if none can be found
*/
public int findNonWhitespaceForward(int position, int bound) {
return scanForward(position, bound, fNonWSDefaultPart);
}
/**
* Finds the smallest position in fDocument
such that the position is >= position
* and < bound
and Character.isWhitespace(fDocument.getChar(pos))
evaluates to false
.
*
* @param position the first character position in fDocument
to be considered
* @param bound the first position in fDocument
to not consider any more, with bound
> position
, or UNBOUND
* @return the smallest position of a non-whitespace character in [position
, bound
), or NOT_FOUND
if none can be found
*/
public int findNonWhitespaceForwardInAnyPartition(int position, int bound) {
return scanForward(position, bound, fNonWS);
}
/**
* Finds the highest position in fDocument
such that the position is <= position
* and > bound
and Character.isWhitespace(fDocument.getChar(pos))
evaluates to false
* and the position is in the default partition.
*
* @param position the first character position in fDocument
to be considered
* @param bound the first position in fDocument
to not consider any more, with bound
< position
, or UNBOUND
* @return the highest position of a non-whitespace character in (bound
, position
] that resides in a Java partition, or NOT_FOUND
if none can be found
*/
public int findNonWhitespaceBackward(int position, int bound) {
return scanBackward(position, bound, fNonWSDefaultPart);
}
/**
* Finds the lowest position p
in fDocument
such that start
<= p <
* bound
and condition.stop(fDocument.getChar(p), p)
evaluates to true
.
*
* @param start the first character position in fDocument
to be considered
* @param bound the first position in fDocument
to not consider any more, with bound
> start
, or UNBOUND
* @param condition the StopCondition
to check
* @return the lowest position in [start
, bound
) for which condition
holds, or NOT_FOUND
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 fDocument
such that the position is >= position
* and < bound
and fDocument.getChar(position) == ch
evaluates to true
* and the position is in the default partition.
*
* @param position the first character position in fDocument
to be considered
* @param bound the first position in fDocument
to not consider any more, with bound
> position
, or UNBOUND
* @param ch the char
to search for
* @return the lowest position of ch
in (bound
, position
] that resides in a Java partition, or NOT_FOUND
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 fDocument
such that the position is >= position
* and < bound
and fDocument.getChar(position) == ch
evaluates to true
for at least one
* ch in chars
and the position is in the default partition.
*
* @param position the first character position in fDocument
to be considered
* @param bound the first position in fDocument
to not consider any more, with bound
> position
, or UNBOUND
* @param chars an array of char
to search for
* @return the lowest position of a non-whitespace character in [position
, bound
) that resides in a Java partition, or NOT_FOUND
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 p
in fDocument
such that bound
< p
<= start
* and condition.stop(fDocument.getChar(p), p)
evaluates to true
.
*
* @param start the first character position in fDocument
to be considered
* @param bound the first position in fDocument
to not consider any more, with bound
< start
, or UNBOUND
* @param condition the StopCondition
to check
* @return the highest position in (bound
, start
for which condition
holds, or NOT_FOUND
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 fDocument
such that the position is <= position
* and > bound
and fDocument.getChar(position) == ch
evaluates to true
for at least one
* ch in chars
and the position is in the default partition.
*
* @param position the first character position in fDocument
to be considered
* @param bound the first position in fDocument
to not consider any more, with bound
< position
, or UNBOUND
* @param ch the char
to search for
* @return the highest position of one element in chars
in (bound
, position
] that resides in a Java partition, or NOT_FOUND
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 fDocument
such that the position is <= position
* and > bound
and fDocument.getChar(position) == ch
evaluates to true
for at least one
* ch in chars
and the position is in the default partition.
*
* @param position the first character position in fDocument
to be considered
* @param bound the first position in fDocument
to not consider any more, with bound
< position
, or UNBOUND
* @param chars an array of char
to search for
* @return the highest position of one element in chars
in (bound
, position
] that resides in a Java partition, or NOT_FOUND
if none can be found
*/
public int scanBackward(int position, int bound, char[] chars) {
return scanBackward(position, bound, new CharacterMatch(chars));
}
/**
* Checks whether position
resides in a default (Java) partition of fDocument
.
*
* @param position the position to be checked
* @return true
if position
is in the default partition of fDocument
, false
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).
*
* * if (condition) * doStuff(); ** *
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
* * @param position the insert position of the new character * @param bound the lowest position to consider * @returntrue
if the code is a conditional statement or loop without a block, false
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;
}
}