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InputBuffer Class Reference

#include <InputBuffer.hpp>

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List of all members.

Public Member Functions

 InputBuffer ()
virtual ~InputBuffer ()
virtual void reset (void)
 Reset the input buffer to empty state.
void commit (void)
virtual void consume ()
virtual void fill (unsigned int amount)
virtual int getChar ()=0
virtual int LA (unsigned int i)
virtual unsigned int mark ()
virtual bool isMarked () const
 Are there any marks active in the InputBuffer.
virtual void rewind (unsigned int mark)
virtual unsigned int entries () const
std::string getLAChars () const
std::string getMarkedChars () const

Protected Member Functions

void syncConsume ()

Protected Attributes

unsigned int nMarkers
unsigned int markerOffset
unsigned int numToConsume
CircularQueue< int > queue

Private Member Functions

 InputBuffer (const InputBuffer &other)
InputBufferoperator= (const InputBuffer &other)

Detailed Description

A Stream of characters fed to the lexer from a InputStream that can be rewound via mark()/rewind() methods.

A dynamic array is used to buffer up all the input characters. Normally, "k" characters are stored in the buffer. More characters may be stored during guess mode (testing syntactic predicate), or when LT(i>k) is referenced. Consumption of characters is deferred. In other words, reading the next character is not done by conume(), but deferred until needed by LA or LT.

See also:
antlr.CharQueue

Constructor & Destructor Documentation

Create a character buffer

virtual InputBuffer::~InputBuffer ( ) [inline, virtual]
InputBuffer::InputBuffer ( const InputBuffer other) [private]

Member Function Documentation

void InputBuffer::commit ( void  ) [inline]

This method updates the state of the input buffer so that the text matched since the most recent mark() is no longer held by the buffer. So, you either do a mark/rewind for failed predicate or mark/commit to keep on parsing without rewinding the input.

virtual void InputBuffer::consume ( ) [inline, virtual]

Mark another character for deferred consumption

unsigned int InputBuffer::entries ( ) const [virtual]

Get the number of non-consumed characters

void InputBuffer::fill ( unsigned int  amount) [virtual]

Ensure that the character buffer is sufficiently full

virtual int InputBuffer::getChar ( ) [pure virtual]

Override this in subclasses to get the next character

Implemented in CharInputBuffer, and CharBuffer.

std::string InputBuffer::getLAChars ( void  ) const

get the current lookahead characters as a string

Warning:
it may treat 0 and EOF values wrong
std::string InputBuffer::getMarkedChars ( void  ) const

get the current marked characters as a string

Warning:
it may treat 0 and EOF values wrong
virtual bool InputBuffer::isMarked ( ) const [inline, virtual]

Are there any marks active in the InputBuffer.

virtual int InputBuffer::LA ( unsigned int  i) [inline, virtual]

Get a lookahead character

unsigned int InputBuffer::mark ( ) [virtual]

Return an integer marker that can be used to rewind the buffer to its current state.

InputBuffer& InputBuffer::operator= ( const InputBuffer other) [private]
virtual void InputBuffer::reset ( void  ) [inline, virtual]

Reset the input buffer to empty state.

Reimplemented in CharInputBuffer.

void InputBuffer::rewind ( unsigned int  mark) [virtual]

Rewind the character buffer to a marker.

Parameters:
markMarker returned previously from mark()
void InputBuffer::syncConsume ( ) [inline, protected]

Sync up deferred consumption


Member Data Documentation

unsigned int InputBuffer::markerOffset [protected]
unsigned int InputBuffer::nMarkers [protected]
unsigned int InputBuffer::numToConsume [protected]

The documentation for this class was generated from the following files: