fr.umlv.tatoo.runtime.buffer.impl
Class UTF8Wrapper<T>

java.lang.Object
  fr.umlv.tatoo.runtime.buffer.impl.UTF8Wrapper<T>

Type Parameters:

T - the type of the token view of the wrapper

All Implemented Interfaces:

LexerBuffer, TokenBuffer<T>

public class UTF8Wrapper<T>
extends Object
implements LexerBuffer, TokenBuffer<T>

The class provides a buffer for using with a lexer build with UTF-8 encoding (UTF8Encoding). It can wrap InputStream and ReadableByteChannel

Author:

Julien Cervelle

Method Summary

void	discard() Discards all characters already recognized by the lexer.
LocationTracker	getLocationProvider() Returns a location provider.
boolean	hasRemaining() Returns true if more characters are availables in the buffer.
int	lastChar() Returns last read char or -1 if not available.
int	next() Reads the next character from the buffer.
boolean	previousWasNewLine() Determines if the last unwinded character was an end of line.
boolean	read() Reads at some bytes from the stream.
void	reset() Moves current position back to first non unwinded character
void	restart() Moves current position back to first non discarded character
void	unwind(int count) Unwinds count characters from the buffer.
T	view() Return a view of the tokens recognized in the buffer.
static UTF8Wrapper<ByteBuffer>	wrap(boolean direct, int capacity, int increment, int chunkSize, ReadableByteChannel readable, LocationTracker tracker) Construct a UTF8Wrapper used by the lexer to process the ReadableByteChannel.
static UTF8Wrapper<InputStream>	wrap(InputStream inputStream, LocationTracker tracker) Constructs an UTF8Wrapper wrapper used by the lexer to process the InputStream.
static UTF8Wrapper<InputStream>	wrap(int capacity, int increment, int chunkSize, InputStream inputStream, LocationTracker tracker) Construct a UTF8Wrapper used by the lexer to process the InputStream.
static UTF8Wrapper<ByteBuffer>	wrap(ReadableByteChannel readable, LocationTracker tracker) Constructs an UTF8Wrapper wrapper used by the lexer to process the ReadableByteChannel.

Methods inherited from class java.lang.Object

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

Method Detail

wrap

public static UTF8Wrapper<InputStream> wrap(int capacity,
                                            int increment,
                                            int chunkSize,
                                            InputStream inputStream,
                                            LocationTracker tracker)

Construct a UTF8Wrapper used by the lexer to process the InputStream. 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

inputStream - the input

tracker - the location tracker

wrap

public static UTF8Wrapper<InputStream> wrap(InputStream inputStream,
                                            LocationTracker tracker)

Constructs an UTF8Wrapper wrapper used by the lexer to process the InputStream.

Parameters:

inputStream - the InputStream to wrap

tracker - the location tracker

wrap

public static UTF8Wrapper<ByteBuffer> wrap(boolean direct,
                                           int capacity,
                                           int increment,
                                           int chunkSize,
                                           ReadableByteChannel readable,
                                           LocationTracker tracker)

Construct a UTF8Wrapper used by the lexer to process the ReadableByteChannel. The parameters specify how the underlying buffer which stores data in allocated and reallocated when more space is needed.

Parameters:

direct - if the ByteBuffer must be direct

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

readable - the input

tracker - the location tracker

Returns:

a new lexer buffer

wrap

public static UTF8Wrapper<ByteBuffer> wrap(ReadableByteChannel readable,
                                           LocationTracker tracker)

Constructs an UTF8Wrapper wrapper used by the lexer to process the ReadableByteChannel.

Parameters:

readable - the ReadableByteChannel to wrap

tracker - the location tracker

Returns:

a new lexer buffer

next

public int next()

Description copied from interface: LexerBuffer

Reads the next character from the buffer. Current position in the buffer is incremented.

Specified by:

next in interface LexerBuffer

Returns:

the next character in the buffer

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

discard

public void discard()

Description copied from interface: LexerBuffer

Discards all characters already recognized by the lexer.

Specified by:

discard in interface LexerBuffer

Specified by:

discard in interface TokenBuffer<T>

restart

public void restart()

Description copied from interface: LexerBuffer

Moves current position back to first non discarded character

Specified by:

restart in interface LexerBuffer

unwind

public void unwind(int count)

Description copied from interface: LexerBuffer

Unwinds count characters from the buffer. count must not be 0.

Specified by:

unwind in interface LexerBuffer

Parameters:

count - the number of characters to unwind

reset

public void reset()

Description copied from interface: LexerBuffer

Moves current position back to first non unwinded character

Specified by:

reset in interface LexerBuffer

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

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.

view

public T view()

Return a view of the tokens recognized in the buffer. If the view has methods to modify its limit, they must not be called.

Specified by:

view in interface TokenBuffer<T>

Returns:

a view of the tokens recognized in the buffer.

See Also:

ReadableByteChannelWrapper.view()

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

getLocationProvider

public LocationTracker getLocationProvider()

Description copied from interface: LexerBuffer

Returns a location provider.

Specified by:

getLocationProvider in interface LexerBuffer

Returns:

the location provider or null if the buffer has no location provider.