fr.umlv.tatoo.runtime.buffer.impl
Class ReaderWrapper

java.lang.Object
  fr.umlv.tatoo.runtime.buffer.impl.AbstractBufferWrapper
      fr.umlv.tatoo.runtime.buffer.impl.ReaderWrapper

All Implemented Interfaces:

LexerBuffer, TokenBuffer<CharSequence>, CharSequence

public class ReaderWrapper
extends AbstractBufferWrapper
implements TokenBuffer<CharSequence>, CharSequence

A ReaderWrapper wraps a Reader in order to allow a lexer to process its content in order to have its tokens extracted.

Author:

Julien

See Also:

Lexer

Constructor Summary

ReaderWrapper(int capacity, int increment, int chunkSize, Reader reader, LocationTracker tracker)
Construct a ReaderWrapper used by the lexer to process the Reader.

ReaderWrapper(Reader reader, LocationTracker tracker)
Constructs a ReaderWrapper with default behavior.

Method Summary

char	charAt(int index)
void	discardImpl()
boolean	hasRemaining() Returns true if more characters are availables in the buffer.
int	lastChar() Returns last read char or -1 if not available.
int	length()
protected int	nextImpl() Returns next character in buffer without taking care of locations
boolean	previousWasNewLine() Determines if the last unwinded character was an end of line.
boolean	read() Reads at some bytes from the stream.
protected void	resetImpl() Moves current position back to first non unwinded character without taking care of locations
protected void	restartImpl()
CharSequence	subSequence(int start, int end)
String	toString() Returns a String representation of the current token
protected void	unwindImpl(int l) Performs unwind operation on buffer without taking care of locations
CharSequence	view() Provides a view of all available tokens.

Methods inherited from class fr.umlv.tatoo.runtime.buffer.impl.AbstractBufferWrapper

discard, getLocationProvider, locationClear, next, reset, restart, unwind

Methods inherited from class java.lang.Object

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

Methods inherited from interface fr.umlv.tatoo.runtime.buffer.TokenBuffer

discard

Constructor Detail

ReaderWrapper

public ReaderWrapper(Reader reader,
                     LocationTracker tracker)

Constructs a ReaderWrapper with default behavior.

Parameters:

reader - the Reader to wrap

tracker - the location tracker

ReaderWrapper

public ReaderWrapper(int capacity,
                     int increment,
                     int chunkSize,
                     Reader reader,
                     LocationTracker tracker)

Construct a ReaderWrapper used by the lexer to process the Reader. The parameters specify how the underlying buffer which stores data in allocated and reallocated when more space is needed.

Parameters:

capacity - the initial capacity

increment - how much to increment the size of the buffer when more space is required

chunkSize - how many bytes are read at once is the input

reader - the input

Method Detail

unwindImpl

protected void unwindImpl(int l)

Description copied from class: AbstractBufferWrapper

Performs unwind operation on buffer without taking care of locations

Specified by:

unwindImpl in class AbstractBufferWrapper

Parameters:

l - the number of characters to unwind

See Also:

LexerBuffer.unwind(int)

resetImpl

protected void resetImpl()

Description copied from class: AbstractBufferWrapper

Moves current position back to first non unwinded character without taking care of locations

Specified by:

resetImpl in class AbstractBufferWrapper

See Also:

LexerBuffer.reset()

previousWasNewLine

public boolean previousWasNewLine()

Description copied from interface: LexerBuffer

Determines if the last unwinded character was an end of line.

Specified by:

previousWasNewLine in interface LexerBuffer

Returns:

true if the last unwinded character was an end of line; false otherwise

hasRemaining

public boolean hasRemaining()

Description copied from interface: LexerBuffer

Returns true if more characters are availables in the buffer. If the end of file has been reached and backtracked by lexer this method must return true.

Specified by:

hasRemaining in interface LexerBuffer

Returns:

true if more characters are availables in the buffer

read

public boolean read()
             throws IOException

Description copied from interface: LexerBuffer

Reads at some bytes from the stream. This operation is optionnal and only used by SimpleLexer.run().

Specified by:

read in interface LexerBuffer

Returns:

false at end of stream

Throws:

IOException - if an i/o operation failed.

nextImpl

protected int nextImpl()

Description copied from class: AbstractBufferWrapper

Returns next character in buffer without taking care of locations

Specified by:

nextImpl in class AbstractBufferWrapper

Returns:

the next character in the buffer

See Also:

LexerBuffer.next()

discardImpl

public void discardImpl()

Specified by:

discardImpl in class AbstractBufferWrapper

view

public CharSequence view()

Description copied from interface: TokenBuffer

Provides a view of all available tokens. Tokens are not copied from the buffer and thus may change during lexer process.

Specified by:

view in interface TokenBuffer<CharSequence>

Returns:

a view of all available tokens

length

public int length()

Specified by:

length in interface CharSequence

charAt

public char charAt(int index)

Specified by:

charAt in interface CharSequence

subSequence

public CharSequence subSequence(int start,
                                int end)

Specified by:

subSequence in interface CharSequence

toString

public String toString()

Returns a String representation of the current token

Specified by:

toString in interface CharSequence

Overrides:

toString in class Object

Returns:

a String representation of the current token

lastChar

public int lastChar()

Description copied from interface: LexerBuffer

Returns last read char or -1 if not available. This method is used for logging and error reporting. This operation is optional since this method can return -1 anytime

Specified by:

lastChar in interface LexerBuffer

Returns:

last read char or -1 if not available

restartImpl

protected void restartImpl()

Specified by:

restartImpl in class AbstractBufferWrapper