Package com.github.javaparser

Class AbstractCharStream

  • All Implemented Interfaces:
    CharStream
    Direct Known Subclasses:
    SimpleCharStream
    public abstract class AbstractCharStream
extends Object
implements CharStream
    An implementation of interface CharStream, where the stream is assumed to contain only ASCII characters (without unicode processing).

    • Field Detail

      • DEFAULT_BUF_SIZE

        public static final int DEFAULT_BUF_SIZE
        Default buffer size if nothing is specified
        See Also:
        Constant Field Values

      • buffer

        protected char[] buffer
        Internal circular buffer

      • bufsize

        protected int bufsize
        Overall buffer size - same as buffer.length

      • bufpos

        protected int bufpos
        Current read position in buffer.

      • available

        protected int available
        The number of unoccupied buffer array positions

      • tokenBegin

        protected int tokenBegin
        The first array index (of `buffer`) that the current token starts

      • inBuf

        protected int inBuf
        Characters in the backup/pushBack buffer

      • maxNextCharInd

        protected int maxNextCharInd

    • Constructor Detail

      • AbstractCharStream

        public AbstractCharStream​(int nStartLine,
                          int nStartColumn,
                          int nBufferSize)
        Constructor.

    • Method Detail

      • reInit

        public final void reInit​(int nStartLine,
                         int nStartColumn,
                         int nBufferSize)
        Reinitialise.

      • streamRead

        protected abstract int streamRead​(char[] aBuf,
                                  int nOfs,
                                  int nLen)
                           throws IOException
        Read from the underlying stream.
        Parameters:
        aBuf - the buffer to be filled
        nOfs - The offset into the buffer. 0-based
        nLen - Number of chars to read.
        Returns:
        Number of effective chars read, or -1 on error.
        Throws:
        IOException

      • streamClose

        protected abstract void streamClose()
                             throws IOException
        Close the underlying stream.
        Throws:
        IOException - If closing fails.

      • getBufSizeAfterExpansion

        protected int getBufSizeAfterExpansion()

      • expandBuff

        protected void expandBuff​(boolean bWrapAround)

      • internalAdjustBuffSize

        protected final void internalAdjustBuffSize()

      • internalSetBufLineColumn

        protected final void internalSetBufLineColumn​(int nLine,
                                              int nColumn)

      • internalUpdateLineColumn

        protected final void internalUpdateLineColumn​(char c)

      • readChar

        public char readChar()
              throws IOException
        Description copied from interface: CharStream
        Get the next character from the selected input. The method of selecting the input is the responsibility of the class implementing this interface.
        Specified by:
        readChar in interface CharStream
        Returns:
        the next character from the selected input
        Throws:
        IOException - on IO error

      • beginToken

        public char beginToken()
                throws IOException
        Specified by:
        beginToken in interface CharStream
        Returns:
        the next character that marks the beginning of the next token. All characters must remain in the buffer between two successive calls to this method to implement backup correctly.
        Throws:
        IOException

      • getBeginColumn

        public int getBeginColumn()
        Specified by:
        getBeginColumn in interface CharStream
        Returns:
        the column number of the first character for current token (being matched after the last call to beginToken).

      • getBeginLine

        public int getBeginLine()
        Specified by:
        getBeginLine in interface CharStream
        Returns:
        the line number of the first character for current token (being matched after the last call to BeginToken).

      • getEndColumn

        public int getEndColumn()
        Specified by:
        getEndColumn in interface CharStream
        Returns:
        the column number of the last character for current token (being matched after the last call to BeginToken).

      • getEndLine

        public int getEndLine()
        Specified by:
        getEndLine in interface CharStream
        Returns:
        the line number of the last character for current token (being matched after the last call to BeginToken).

      • backup

        public void backup​(int nAmount)
        Description copied from interface: CharStream
        Backs up the input stream by amount steps. Lexer calls this method if it had already read some characters, but could not use them to match a (longer) token. So, they will be used again as the prefix of the next token and it is the implemetation's responsibility to do this right.
        Specified by:
        backup in interface CharStream
        Parameters:
        nAmount - Number of chars to back up.

      • getImage

        public String getImage()
        Specified by:
        getImage in interface CharStream
        Returns:
        a string made up of characters from the marked token beginning to the current buffer position. Implementations have the choice of returning anything that they want to. For example, for efficiency, one might decide to just return null, which is a valid implementation.

      • getSuffix

        public char[] getSuffix​(int len)
        Specified by:
        getSuffix in interface CharStream
        Returns:
        an array of characters that make up the suffix of length 'len' for the currently matched token. This is used to build up the matched string for use in actions in the case of MORE. A simple and inefficient implementation of this is as follows: 
           {
      String t = getImage();
      return t.substring(t.length() - len, t.length()).toCharArray();
   }

      • done

        public void done()
        Description copied from interface: CharStream
        The lexer calls this function to indicate that it is done with the stream and hence implementations can free any resources held by this class. Again, the body of this function can be just empty and it will not affect the lexer's operation.
        Specified by:
        done in interface CharStream

      • getTabSize

        public final int getTabSize()
        Specified by:
        getTabSize in interface CharStream
        Returns:
        Current tab size.

      • setTabSize

        public final void setTabSize​(int nTabSize)
        Description copied from interface: CharStream
        Set the tab size to use.
        Specified by:
        setTabSize in interface CharStream
        Parameters:
        nTabSize - spaces per tab

      • adjustBeginLineColumn

        public final void adjustBeginLineColumn​(int nNewLine,
                                        int newCol)
        Method to adjust line and column numbers for the start of a token. This is used internally to

      • getLine

        protected final int getLine()
        Returns:
        the current line number. 0-based.

      • getColumn

        protected final int getColumn()
        Returns:
        the current column number. 0-based.

      • isTrackLineColumn

        public final boolean isTrackLineColumn()
        Specified by:
        isTrackLineColumn in interface CharStream
        Returns:
        true if line number and column numbers should be tracked.

      • setTrackLineColumn

        public final void setTrackLineColumn​(boolean bTrackLineColumn)
        Description copied from interface: CharStream
        Enable or disable line number and column number tracking.
        Specified by:
        setTrackLineColumn in interface CharStream
        Parameters:
        bTrackLineColumn - true to track it, false to not do it.