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 org.eclipse.jdt.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 org.eclipse.jdt.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 Character#isJavaIdentifierPart(char)}) character.
- */
- private static class NonJavaIdentifierPart implements StopCondition {
- /*
- * @see org.eclipse.jdt.internal.ui.text.JavaHeuristicScanner.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 NonJavaIdentifierPart
- */
- private class NonJavaIdentifierPartDefaultPartition extends NonJavaIdentifierPart {
- /*
- * @see org.eclipse.jdt.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 org.eclipse.jdt.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 org.eclipse.jdt.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 (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);
-
-
- } 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 (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);
-
-
- } 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;
- }
-}