Package org.eclipse.m2m.atl.adt.ui.text

Class AtlHeuristicScanner

  • All Implemented Interfaces:
    Symbols
    public class AtlHeuristicScanner
extends java.lang.Object
implements Symbols
    Utility methods for heuristic based manipulations in an incomplete source file.

    An instance holds some internal position in the document and is therefore not threadsafe.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      protected class  AtlHeuristicScanner.SkippingScopeMatch
      Acts like character match, but skips all scopes introduced by parenthesis, brackets, and braces.
      static interface  AtlHeuristicScanner.StopCondition
      Specifies the stop condition, upon which the scanXXX methods will decide whether to keep scanning or not.

    • Constructor Summary

      Constructors 
      Constructor Description
      AtlHeuristicScanner​(org.eclipse.jface.text.IDocument document)
      Calls this(document, IAtlPartitions.Atl_PARTITIONING, IDocument.DEFAULT_CONTENT_TYPE).
      AtlHeuristicScanner​(org.eclipse.jface.text.IDocument document, java.lang.String partitioning, java.lang.String partition)
      Creates a new instance.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int findClosingPeer​(int start, char openingPeer, char closingPeer)
      Returns the position of the closing peer character (forward search).
      int findNonWhitespaceBackward​(int position, int bound)
      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.
      int findNonWhitespaceForward​(int position, int bound)
      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.
      int findNonWhitespaceForwardInAnyPartition​(int position, int bound)
      Finds the smallest position in fDocument such that the position is >= position and < bound and Character.isWhitespace(fDocument.getChar(pos)) evaluates to false.
      int findOpeningPeer​(int start, char openingPeer, char closingPeer)
      Returns the position of the opening peer character (backward search).
      org.eclipse.jface.text.IRegion findSurroundingBlock​(int offset)
      Computes the surrounding block around offset.
      int getPosition()
      Returns the most recent internal scan position.
      boolean isBracelessBlockStart​(int position, int bound)
      Checks if the line seems to be an open condition not followed by a block (i.e.
      boolean isDefaultPartition​(int position)
      Checks whether position resides in a default (Atl) partition of fDocument.
      int nextToken​(int start, int bound)
      Returns the next token in forward direction, starting at start, and not extending further than bound.
      int previousToken​(int start, int bound)
      Returns the next token in backward direction, starting at start, and not extending further than bound.
      int scanBackward​(int position, int bound, char 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.
      int scanBackward​(int position, int bound, char[] chars)
      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.
      int scanBackward​(int start, int bound, AtlHeuristicScanner.StopCondition condition)
      Finds the highest position p in fDocument such that bound < p <= start and condition.stop(fDocument.getChar(p), p) evaluates to true.
      int scanForward​(int position, int bound, char ch)
      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.
      int scanForward​(int position, int bound, char[] chars)
      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.
      int scanForward​(int start, int bound, AtlHeuristicScanner.StopCondition condition)
      Finds the lowest position p in fDocument such that start <= p < bound and condition.stop(fDocument.getChar(p), p) evaluates to true.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • NOT_FOUND

        public static final int NOT_FOUND
        Returned by all methods when the requested position could not be found, or if a BadLocationException was thrown while scanning.
        See Also:
        Constant Field Values

      • UNBOUND

        public static final int UNBOUND
        Special bound parameter that means either -1 (backward scanning) or fDocument.getLength() (forward scanning).
        See Also:
        Constant Field Values

    • Constructor Detail

      • AtlHeuristicScanner

        public AtlHeuristicScanner​(org.eclipse.jface.text.IDocument document)
        Calls this(document, IAtlPartitions.Atl_PARTITIONING, IDocument.DEFAULT_CONTENT_TYPE).
        Parameters:
        document - the document to scan.

      • AtlHeuristicScanner

        public AtlHeuristicScanner​(org.eclipse.jface.text.IDocument document,
                           java.lang.String partitioning,
                           java.lang.String partition)
        Creates a new instance.
        Parameters:
        document - the document to scan
        partitioning - the partitioning to use for scanning
        partition - the partition to scan in

    • Method Detail

      • findClosingPeer

        public int findClosingPeer​(int start,
                           char openingPeer,
                           char 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.

        Note that start must not point to the opening peer, but to the first character being searched.

        Parameters:
        start - the start position
        openingPeer - the opening peer character (e.g. '{')
        closingPeer - the closing peer character (e.g. '}')
        Returns:
        the matching peer character position, or NOT_FOUND

      • findNonWhitespaceBackward

        public int findNonWhitespaceBackward​(int position,
                                     int bound)
        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.
        Parameters:
        position - the first character position in fDocument to be considered
        bound - the first position in fDocument to not consider any more, with bound < position, or UNBOUND
        Returns:
        the highest position of a non-whitespace character in (bound, position] that resides in a Atl partition, or NOT_FOUND if none can be found

      • findNonWhitespaceForward

        public int findNonWhitespaceForward​(int position,
                                    int bound)
        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.
        Parameters:
        position - the first character position in fDocument to be considered
        bound - the first position in fDocument to not consider any more, with bound > position, or UNBOUND
        Returns:
        the smallest position of a non-whitespace character in [position, bound) that resides in a Atl partition, or NOT_FOUND if none can be found

      • findNonWhitespaceForwardInAnyPartition

        public int findNonWhitespaceForwardInAnyPartition​(int position,
                                                  int bound)
        Finds the smallest position in fDocument such that the position is >= position and < bound and Character.isWhitespace(fDocument.getChar(pos)) evaluates to false.
        Parameters:
        position - the first character position in fDocument to be considered
        bound - the first position in fDocument to not consider any more, with bound > position, or UNBOUND
        Returns:
        the smallest position of a non-whitespace character in [position, bound), or NOT_FOUND if none can be found

      • findOpeningPeer

        public int findOpeningPeer​(int start,
                           char openingPeer,
                           char 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.

        Note that start must not point to the closing peer, but to the first character being searched.

        Parameters:
        start - the start position
        openingPeer - the opening peer character (e.g. '{')
        closingPeer - the closing peer character (e.g. '}')
        Returns:
        the matching peer character position, or NOT_FOUND

      • findSurroundingBlock

        public org.eclipse.jface.text.IRegion findSurroundingBlock​(int offset)
        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.
        Parameters:
        offset - the offset for which the surrounding block is computed
        Returns:
        a region describing the surrounding block, or null if none can be found

      • getPosition

        public int getPosition()
        Returns the most recent internal scan position.
        Returns:
        the most recent internal scan position.

      • isBracelessBlockStart

        public boolean isBracelessBlockStart​(int position,
                                     int bound)
        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

        Parameters:
        position - the insert position of the new character
        bound - the lowest position to consider
        Returns:
        true if the code is a conditional statement or loop without a block, false otherwise

      • isDefaultPartition

        public boolean isDefaultPartition​(int position)
        Checks whether position resides in a default (Atl) partition of fDocument.
        Parameters:
        position - the position to be checked
        Returns:
        true if position is in the default partition of fDocument, false otherwise

      • nextToken

        public int nextToken​(int start,
                     int bound)
        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 Symbols. After a call, getPosition() will return the position just after the scanned token (i.e. the next position that will be scanned).
        Parameters:
        start - the first character position in the document to consider
        bound - the first position not to consider any more
        Returns:
        a constant from Symbols describing the next token

      • previousToken

        public int previousToken​(int start,
                         int bound)
        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 Symbols. After a call, getPosition() will return the position just before the scanned token starts (i.e. the next position that will be scanned).
        Parameters:
        start - the first character position in the document to consider
        bound - the first position not to consider any more
        Returns:
        a constant from Symbols describing the previous token

      • scanBackward

        public int scanBackward​(int position,
                        int bound,
                        char 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.
        Parameters:
        position - the first character position in fDocument to be considered
        bound - the first position in fDocument to not consider any more, with bound < position, or UNBOUND
        ch - the char to search for
        Returns:
        the highest position of one element in chars in (bound, position] that resides in a Atl partition, or NOT_FOUND if none can be found

      • scanBackward

        public int scanBackward​(int position,
                        int bound,
                        char[] chars)
        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.
        Parameters:
        position - the first character position in fDocument to be considered
        bound - the first position in fDocument to not consider any more, with bound < position, or UNBOUND
        chars - an array of char to search for
        Returns:
        the highest position of one element in chars in (bound, position] that resides in a Atl partition, or NOT_FOUND if none can be found

      • scanBackward

        public int scanBackward​(int start,
                        int bound,
                        AtlHeuristicScanner.StopCondition condition)
        Finds the highest position p in fDocument such that bound < p <= start and condition.stop(fDocument.getChar(p), p) evaluates to true.
        Parameters:
        start - the first character position in fDocument to be considered
        bound - the first position in fDocument to not consider any more, with bound < start, or UNBOUND
        condition - the StopCondition to check
        Returns:
        the highest position in (bound, start for which condition holds, or NOT_FOUND if none can be found

      • scanForward

        public int scanForward​(int position,
                       int bound,
                       char ch)
        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.
        Parameters:
        position - the first character position in fDocument to be considered
        bound - the first position in fDocument to not consider any more, with bound > position, or UNBOUND
        ch - the char to search for
        Returns:
        the lowest position of ch in (bound, position] that resides in a Atl partition, or NOT_FOUND if none can be found

      • scanForward

        public int scanForward​(int position,
                       int bound,
                       char[] chars)
        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.
        Parameters:
        position - the first character position in fDocument to be considered
        bound - the first position in fDocument to not consider any more, with bound > position, or UNBOUND
        chars - an array of char to search for
        Returns:
        the lowest position of a non-whitespace character in [position, bound ) that resides in a Atl partition, or NOT_FOUND if none can be found

      • scanForward

        public int scanForward​(int start,
                       int bound,
                       AtlHeuristicScanner.StopCondition condition)
        Finds the lowest position p in fDocument such that start <= p < bound and condition.stop(fDocument.getChar(p), p) evaluates to true.
        Parameters:
        start - the first character position in fDocument to be considered
        bound - the first position in fDocument to not consider any more, with bound > start, or UNBOUND
        condition - the StopCondition to check
        Returns:
        the lowest position in [start, bound) for which condition holds, or NOT_FOUND if none can be found