org.apache.velocity.runtime.parser

Class VelocityCharStream

Implemented Interfaces:
CharStream

public final class VelocityCharStream
extends java.lang.Object
implements CharStream

An implementation of interface CharStream, where the stream is assumed to contain only ASCII characters (without unicode processing).

Nested Class Summary

Field Summary

(package private) int
available
private int[]
bufcolumn
private char[]
buffer
private int[]
bufline
int
bufpos
(package private) int
bufsize
private int
column
private int
inBuf
private java.io.Reader
inputStream
private int
line
private int
maxNextCharInd
private boolean
prevCharIsCR
private boolean
prevCharIsLF
static boolean
staticFlag
(package private) int
tokenBegin

Constructor Summary

VelocityCharStream(java.io.InputStream dstream, int startline, int startcolumn)
VelocityCharStream(java.io.InputStream dstream, int startline, int startcolumn, int buffersize)
VelocityCharStream(java.io.Reader dstream, int startline, int startcolumn)
VelocityCharStream(java.io.Reader dstream, int startline, int startcolumn, int buffersize)

Method Summary

char
BeginToken()
Returns the next character that marks the beginning of the next token.
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.
private void
ExpandBuff(boolean wrapAround)
private void
FillBuff()
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.
void
ReInit(java.io.InputStream dstream, int startline, int startcolumn)
void
ReInit(java.io.InputStream dstream, int startline, int startcolumn, int buffersize)
void
ReInit(java.io.Reader dstream, int startline, int startcolumn)
void
ReInit(java.io.Reader dstream, int startline, int startcolumn, int buffersize)
private void
UpdateLineColumn(char c)
void
adjustBeginLineColumn(int newLine, int newCol)
Method to adjust line and column numbers for the start of a token.
void
backup(int amount)
Backs up the input stream by amount steps.
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
getColumn()
Deprecated.
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).
int
getLine()
Deprecated.
char
readChar()
Returns the next character from the selected input.

Field Details

available

(package private)  int available


bufcolumn

private int[] bufcolumn


buffer

private char[] buffer


bufline

private int[] bufline


bufpos

public int bufpos


bufsize

(package private)  int bufsize


column

private int column


inBuf

private int inBuf


inputStream

private java.io.Reader inputStream


line

private int line


maxNextCharInd

private int maxNextCharInd


prevCharIsCR

private boolean prevCharIsCR


prevCharIsLF

private boolean prevCharIsLF


staticFlag

public static final boolean staticFlag

Field Value:
false


tokenBegin

(package private)  int tokenBegin

Constructor Details

VelocityCharStream

public VelocityCharStream(java.io.InputStream dstream,
                          int startline,
                          int startcolumn)


VelocityCharStream

public VelocityCharStream(java.io.InputStream dstream,
                          int startline,
                          int startcolumn,
                          int buffersize)


VelocityCharStream

public VelocityCharStream(java.io.Reader dstream,
                          int startline,
                          int startcolumn)


VelocityCharStream

public VelocityCharStream(java.io.Reader dstream,
                          int startline,
                          int startcolumn,
                          int buffersize)

Method Details

BeginToken

public final 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


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


ExpandBuff

private final void ExpandBuff(boolean wrapAround)


FillBuff

private final void FillBuff()
            throws java.io.IOException


GetImage

public final 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 final 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


ReInit

public void ReInit(java.io.InputStream dstream,
                   int startline,
                   int startcolumn)


ReInit

public void ReInit(java.io.InputStream dstream,
                   int startline,
                   int startcolumn,
                   int buffersize)


ReInit

public void ReInit(java.io.Reader dstream,
                   int startline,
                   int startcolumn)


ReInit

public void ReInit(java.io.Reader dstream,
                   int startline,
                   int startcolumn,
                   int buffersize)


UpdateLineColumn

private final void UpdateLineColumn(char c)


adjustBeginLineColumn

public void adjustBeginLineColumn(int newLine,
                                  int newCol)
Method to adjust line and column numbers for the start of a token.


backup

public final 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


getBeginColumn

public final 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 final 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


getColumn

public final int getColumn()

Deprecated.

Specified by:
getColumn in interface CharStream

See Also:
getEndColumn()


getEndColumn

public final 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 final 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


getLine

public final int getLine()

Deprecated.

Specified by:
getLine in interface CharStream

See Also:
getEndLine()


readChar

public final 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


Copyright © 2003 Apache Software Foundation. All Rights Reserved.