hlt.language.io

Class LAReader

java.lang.Object

java.io.Reader

hlt.language.io.LAReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.lang.Readable

public class LAReader
extends java.io.Reader

This class provides the convenience for doing lookaheads of arbitrary length on a given Reader.

Version:

Last modified on Wed Jun 20 13:57:09 2012 by hak

Author:

Hassan Aït-Kaci

See Also:

LAStreamTokenizer

Copyright:

© by the author

Constructor Summary

Constructors

Constructor and Description
LAReader(java.io.Reader reader) Constructs a LAReader with the specified Reader.
LAReader(java.io.Reader reader, int size) Constructs a LAReader with the specified Reader and buffer size.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Closes this LAReader.
java.lang.String	lookahead() Returns a lookahead string of length equal to the buffer's.
java.lang.String	lookahead(int n) Returns the string of the n characters to be read next.
void	mark(int readAheadLimit) This method does nothing because marking is not supported.
boolean	markSupported() Returns false because it there is no simple way to accommodate marking with the lookahead buffer.
int	read() Consumes and returns the next character in the LAReader.
int	read(char[] cbuf) Read characters into an array.
int	read(char[] cbuf, int off, int len) Read characters into a portion of an array.
boolean	ready() Returns true iff there is a character available to be read.
void	reset() This method does nothing because marking is not supported.
void	resizeBuffer(int size) Resizes the lookahead buffer to the specified size.
long	skip(long n) Skip n characters, up to EOF (or, more generally, any negative value returned by read()).
java.lang.String	toString() Returns a string describing the current buffer state.

Methods inherited from class java.io.Reader

read

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

LAReader

public LAReader(java.io.Reader reader)

Constructs a LAReader with the specified Reader.

LAReader

public LAReader(java.io.Reader reader,
        int size)

Constructs a LAReader with the specified Reader and buffer size.

Method Detail

read

public final int read()
               throws java.io.IOException

Consumes and returns the next character in the LAReader.

Overrides:

read in class java.io.Reader

Throws:

java.io.IOException

lookahead

public final java.lang.String lookahead(int n)
                                 throws java.io.IOException

Returns the string of the n characters to be read next. If less than n characters are available in the currentl buffer, it is first refilled. If n is greater than BUFFER_SIZE, the buffer is first resized to n and refilled. If the end of file is read, or the reader becomes non ready before n characters are consumed, only those characters that have been already read are used (and the lookahead is then shorter than n). If the reader is not ready or only the end of file remains, the empty string is returned.

Throws:

java.io.IOException

lookahead

public final java.lang.String lookahead()
                                 throws java.io.IOException

Returns a lookahead string of length equal to the buffer's.

Throws:

java.io.IOException

resizeBuffer

public void resizeBuffer(int size)
                  throws java.io.IOException

Resizes the lookahead buffer to the specified size.

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Closes this LAReader.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in class java.io.Reader

Throws:

java.io.IOException

toString

public java.lang.String toString()

Returns a string describing the current buffer state.

Overrides:

toString in class java.lang.Object

read

public int read(char[] cbuf,
       int off,
       int len)
         throws java.io.IOException

Read characters into a portion of an array.

Specified by:

read in class java.io.Reader

Parameters:

cbuf - Destination buffer

off - Offset at which to start storing characters

len - Maximum number of characters to read

Returns:

Number of characters read, or IO.EOF.

Throws:

java.io.IOException - If an I/O error occurs

read

public int read(char[] cbuf)
         throws java.io.IOException

Read characters into an array.

Overrides:

read in class java.io.Reader

Parameters:

cbuf - Destination buffer

Returns:

Number of characters read, or one of IO.EOF, IO.SOI, or IO.EOI.

Throws:

java.io.IOException - If an I/O error occurs

skip

public long skip(long n)
          throws java.io.IOException

Skip n characters, up to EOF (or, more generally, any negative value returned by read()).

Overrides:

skip in class java.io.Reader

Parameters:

n - The number of characters to skip

Returns:

The number of characters actually skipped

Throws:

java.lang.IllegalArgumentException - If n is negative

java.io.IOException - If an I/O error occurs

ready

public boolean ready()
              throws java.io.IOException

Returns true iff there is a character available to be read.

Overrides:

ready in class java.io.Reader

Throws:

java.io.IOException

markSupported

public boolean markSupported()

Returns false because it there is no simple way to accommodate marking with the lookahead buffer.

Overrides:

markSupported in class java.io.Reader

mark

public void mark(int readAheadLimit)
          throws java.io.IOException

This method does nothing because marking is not supported.

Overrides:

mark in class java.io.Reader

Throws:

java.io.IOException

reset

public void reset()
           throws java.io.IOException

This method does nothing because marking is not supported.

Overrides:

reset in class java.io.Reader

Throws:

java.io.IOException