antlr::InputBuffer Class Reference

#include <InputBuffer.hpp>

Collaboration diagram for antlr::InputBuffer:

[legend]

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)
InputBuffer &	operator= (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

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Constructor & Destructor Documentation

antlr::InputBuffer::InputBuffer

(

)

[inline]

Create a character buffer

virtual antlr::InputBuffer::~InputBuffer

(

)

[inline, virtual]

antlr::InputBuffer::InputBuffer

(

const InputBuffer &

other

)

[private]

---

Member Function Documentation

void antlr::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 antlr::InputBuffer::consume

(

)

[inline, virtual]

Mark another character for deferred consumption

unsigned int antlr::InputBuffer::entries

(

)

const [virtual]

Get the number of non-consumed characters

void antlr::InputBuffer::fill

(

unsigned int

amount

)

[virtual]

Ensure that the character buffer is sufficiently full

virtual int antlr::InputBuffer::getChar

(

)

[pure virtual]

Override this in subclasses to get the next character

std::string antlr::InputBuffer::getLAChars

(

void

)

const

get the current lookahead characters as a string

Warning:

it may treat 0 and EOF values wrong

std::string antlr::InputBuffer::getMarkedChars

(

void

)

const

get the current marked characters as a string

Warning:

it may treat 0 and EOF values wrong

virtual bool antlr::InputBuffer::isMarked

(

)

const [inline, virtual]

Are there any marks active in the InputBuffer.

virtual int antlr::InputBuffer::LA

(

unsigned int

i

)

[inline, virtual]

Get a lookahead character

unsigned int antlr::InputBuffer::mark

(

)

[virtual]

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

InputBuffer& antlr::InputBuffer::operator=

(

const InputBuffer &

other

)

[private]

virtual void antlr::InputBuffer::reset

(

void

)

[inline, virtual]

Reset the input buffer to empty state.

void antlr::InputBuffer::rewind

(

unsigned int

mark

)

[virtual]

Rewind the character buffer to a marker.

Parameters:

mark

Marker returned previously from mark()

void antlr::InputBuffer::syncConsume

(

)

[inline, protected]

Sync up deferred consumption

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Member Data Documentation

unsigned int antlr::InputBuffer::markerOffset [protected]

unsigned int antlr::InputBuffer::nMarkers [protected]

unsigned int antlr::InputBuffer::numToConsume [protected]

CircularQueue<int> antlr::InputBuffer::queue [protected]

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

• antlr/InputBuffer.hpp
• src/InputBuffer.cpp