Package com.google.common.css.compiler.ast

Class StringCharStream

  • All Implemented Interfaces:
    CharStream
    public class StringCharStream
extends java.lang.Object
implements CharStream
    Efficient String based CharStream implementation.

    • Constructor Summary

      Constructors 
      Constructor Description
      StringCharStream​(java.lang.String inputString)
      Creates a character stream for a given string.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void backup​(int amount)
      Backs up the input stream by amount steps.
      char beginToken()
      Returns the next character that marks the beginning of the next token.
      int convertToCharacterIndex​(int lineNumber, int indexInLine)
      Returns an absolute character location for given line and column location.
      void done()
      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.
      int getBeginColumn()
      Returns the column number of the first character for current token (being matched after the last call to beginToken).
      int getBeginLine()
      Returns the line number of the first character for current token (being matched after the last call to beginToken).
      int getCharIndex()  
      int getEndColumn()
      Returns the column number of the last character for current token (being matched after the last call to beginToken).
      int getEndLine()
      Returns the line number of the last character for current token (being matched after the last call to beginToken).
      java.lang.String getImage()
      Returns a string made up of characters from the marked token beginning to the current buffer position.
      char[] getSuffix​(int len)
      Returns an array of characters that make up the suffix of length 'len' for the currently matched token.
      int getTabSize()  
      boolean getTrackLineColumn()  
      char readChar()
      Returns the next character from the selected input.
      void setTabSize​(int tabSize)  
      void setTrackLineColumn​(boolean trackLineColumn)  

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • StringCharStream

        public StringCharStream​(java.lang.String inputString)
        Creates a character stream for a given string.
        Parameters:
        inputString - input string for this stream

    • Method Detail

      • convertToCharacterIndex

        public int convertToCharacterIndex​(int lineNumber,
                                   int indexInLine)
        Returns an absolute character location for given line and column location.
        Parameters:
        lineNumber - line number (1 based)
        indexInLine - column number (1 based)
        Returns:
        0 based absolute character index in the input string

      • getCharIndex

        public int getCharIndex()
        Returns:
        index of last read character

      • readChar

        public char readChar()
              throws java.io.IOException
        Returns the next character from the selected input. The method of selecting the input is the responsibility of the class implementing this interface. Can throw any java.io.IOException.
        Specified by:
        readChar in interface CharStream
        Throws:
        java.io.IOException

      • getEndColumn

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

      • getEndLine

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

      • getBeginColumn

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

      • getBeginLine

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

      • backup

        public void backup​(int amount)
        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:
        amount - amount

      • beginToken

        public char beginToken()
                throws java.io.IOException
        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.
        Specified by:
        beginToken in interface CharStream
        Returns:
        next character
        Throws:
        java.io.IOException

      • getImage

        public java.lang.String getImage()
        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.
        Specified by:
        getImage in interface CharStream

      • getSuffix

        public char[] getSuffix​(int len)
        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(); }

        Specified by:
        getSuffix in interface CharStream

      • done

        public void done()
        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

      • setTabSize

        public void setTabSize​(int tabSize)
        Specified by:
        setTabSize in interface CharStream

      • setTrackLineColumn

        public void setTrackLineColumn​(boolean trackLineColumn)
        Specified by:
        setTrackLineColumn in interface CharStream