package org.eclipse.dltk.ruby.internal.ui.text;
import java.util.Arrays;
import org.eclipse.core.runtime.Assert;
import org.eclipse.dltk.ui.DLTKUIPlugin;
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;
public abstract class ScriptHeuristicScanner implements ISymbols {
/**
* 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.
*/
protected 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 Character#isWhitespace(char)}) character.
*/
protected static class NonWhitespace extends StopCondition {
@Override
public boolean stop(char ch, int position, boolean forward) {
return !Character.isWhitespace(ch);
}
}
/**
* Stops upon a non-whitespace character in the default partition.
*
* @see RubyHeuristicScanner.NonWhitespace
*/
protected final class NonWhitespaceDefaultPartition extends NonWhitespace {
@Override
public boolean stop(char ch, int position, boolean forward) {
return super.stop(ch, position, true)
&& isDefaultPartition(position);
}
@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-java identifier (as defined by
* {@link Character#isJavaIdentifierPart(char)}) character.
*/
protected class NonIdentifierPart extends StopCondition {
@Override
public boolean stop(char ch, int position, boolean forward) {
return !isValidIdentifierPart(ch);
}
}
/**
* Stops upon a non-java identifier character in the default partition.
*
* @see JavaHeuristicScanner.NonIdentifierPart
*/
protected final class NonIdentifierPartDefaultPartition extends
NonIdentifierPart {
@Override
public boolean stop(char ch, int position, boolean forward) {
return super.stop(ch, position, true)
|| !isDefaultPartition(position);
}
@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.
*/
protected 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);
}
}
/**
* 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 = '=';
private static final char LANGLE = '<';
private static final char RANGLE = '>';
private static final char BACKSLASH = '\\';
private static final char SLASH = '/';
private static final char PLUS = '+';
private static final char MINUS = '-';
private static final char STAR = '*';
/* preset stop conditions */
private final StopCondition fNonWSDefaultPart = new NonWhitespaceDefaultPartition();
private final static StopCondition fNonWS = new NonWhitespace();
private final StopCondition fNonIdentifier = new NonIdentifierPartDefaultPartition();
/** 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;
/**
* The most recently used partition.
*
* @since 3.2
*/
private ITypedRegion fCachedPartition = new TypedRegion(-1, 0,
"__no_partition_at_all"); //$NON-NLS-1$
/**
* @param document
* the document to scan
* @param partitioning
* the partitioning to use for scanning
* @param partition
* the partition to scan in
*/
protected ScriptHeuristicScanner(IDocument document, String partitioning,
String partition) {
Assert.isLegal(document != null);
Assert.isLegal(partitioning != null);
Assert.isLegal(partition != null);
fDocument = document;
fPartitioning = partitioning;
fPartition = partition;
}
/**
* Returns the most recent internal scan position.
*
* @return the most recent internal scan position.
*/
public int getPosition() {
return fPos;
}
/**
* Sets the most recent internal scan position.
*
* @return the most recent internal scan position.
*/
protected void setPosition(int pos) {
fPos = pos;
}
/**
* Returns the scanned document
*
* @return the scanned document
*/
public IDocument getDocument() {
return fDocument;
}
/**
* 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
*/
protected ITypedRegion getPartition(int position) {
if (!contains(fCachedPartition, position)) {
Assert.isTrue(position >= 0);
Assert.isTrue(position <= fDocument.getLength());
try {
fCachedPartition = TextUtilities.getPartition(fDocument,
fPartitioning, position, false);
} catch (BadLocationException e) {
fCachedPartition = new TypedRegion(position, 0,
"__no_partition_at_all"); //$NON-NLS-1$
}
}
return fCachedPartition;
}
/**
* Returns <code>true</code> if <code>region</code> contains
* <code>position</code>.
*
* @param region
* a region
* @param position
* an offset
* @return <code>true</code> if <code>region</code> contains
* <code>position</code>
* @since 3.2
*/
private boolean contains(IRegion region, int position) {
int offset = region.getOffset();
return offset <= position && position < offset + region.getLength();
}
/**
* Checks whether <code>position</code> resides in a default 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) {
return fPartition.equals(getPartition(position).getType());
}
/**
* 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.isLegal(start >= 0);
if (bound == UNBOUND)
bound = fDocument.getLength();
Assert.isLegal(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 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.isLegal(bound >= -1);
Assert.isLegal(start <= fDocument.getLength());
try {
fPos = start - 1;
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 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 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>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 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 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>.
*
* @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 findNonWhitespaceBackwardInAnyPartition(int position, int bound) {
return scanBackward(position, bound, fNonWS);
}
protected int getGenericToken(char ch) {
switch (ch) {
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;
case LANGLE:
return TokenLESSTHAN;
case RANGLE:
return TokenGREATERTHAN;
case BACKSLASH:
return TokenBACKSLASH;
case SLASH:
return TokenSLASH;
case PLUS:
return TokenPLUS;
case MINUS:
return TokenMINUS;
case STAR:
return TokenSTAR;
default:
return TokenOTHER;
}
}
/**
* 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++;
int token = getGenericToken(fChar);
if (token != TokenOTHER)
return token;
// else
if (isValidIdentifierPart(fChar)) {
// assume an identifier or keyword
int from = pos, to;
pos = findNonIdentifierForward(pos, bound);
if (pos == NOT_FOUND)
to = bound == UNBOUND ? fDocument.getLength() : bound;
else
to = pos;
return getToken(from, to);
} else {
// 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;
int token = getGenericToken(fChar);
if (token != TokenOTHER)
return token;
// else
if (isValidIdentifierPart(fChar)) {
// assume an ident or keyword
int from, to = pos + 1;
pos = findNonIdentifierBackward(pos, bound);
if (pos == NOT_FOUND)
from = bound == UNBOUND ? 0 : bound;
else
from = pos + 1;
return getToken(from, to);
} else {
// operators, number literals etc
return TokenOTHER;
}
}
private int getToken(int from, int to) {
String identOrKeyword;
try {
identOrKeyword = fDocument.get(from, to - from);
} catch (BadLocationException e) {
return TokenEOF;
}
return getToken(from, identOrKeyword);
}
public int findNonIdentifierForward(int offset, int bound) {
return scanForward(offset, bound, fNonIdentifier);
}
public int findNonIdentifierBackward(int offset, int bound) {
return scanBackward(offset, bound, fNonIdentifier);
}
public int findPrecedingNotEmptyLine(int offset) {
try {
int notEmptyPositioin = findNonWhitespaceBackward(offset, UNBOUND);
if (notEmptyPositioin != NOT_FOUND) {
return fDocument.getLineInformationOfOffset(notEmptyPositioin)
.getOffset();
}
} catch (BadLocationException e) {
DLTKUIPlugin.log(e);
}
return 0;
}
/**
* 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) {
return findClosingPeer(start, UNBOUND, openingPeer, closingPeer);
}
/**
* 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 bound the bound
* @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, int bound, final char openingPeer, final char closingPeer) {
Assert.isLegal(start >= 0);
try {
CharacterMatch match= new CharacterMatch(new char[] {openingPeer, closingPeer});
int depth= 1;
start -= 1;
while (true) {
start= scanForward(start + 1, bound, match);
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) {
return findOpeningPeer(start, UNBOUND, openingPeer, closingPeer);
}
/**
* 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 bound the bound
* @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, int bound, char openingPeer, char closingPeer) {
Assert.isLegal(start <= fDocument.getLength());
try {
final CharacterMatch match= new CharacterMatch(new char[] {openingPeer, closingPeer});
int depth= 1;
start += 1;
while (true) {
start= scanBackward(start - 1, bound, match);
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;
}
}
public IRegion findWordAt(int offset) {
try {
IRegion line = fDocument.getLineInformationOfOffset(offset);
int start = findNonIdentifierBackward(offset, line.getOffset());
int end = findNonIdentifierForward(offset, line.getOffset() + line.getLength());
if (start == NOT_FOUND)
start = line.getOffset();
else
start += 1;
if (end == NOT_FOUND)
end = line.getOffset() + line.getLength();
int length = end - start;
if (length > 0)
return new Region(start, length);
} catch (BadLocationException e) {
DLTKUIPlugin.log(e);
}
return null;
}
/**
* 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 ISymbols}
*/
public abstract int getToken(int position, String s);
/**
* @return true if symbol is valid identifier part
*/
protected boolean isValidIdentifierPart(char symbol) {
return Character.isJavaIdentifierPart(symbol);
}
}