C# Class Antlr4.Runtime.UnbufferedCharStream

Do not buffer up the entire char stream.

Do not buffer up the entire char stream. It does keep a small buffer for efficiency and also buffers while a mark exists (set by the lookahead prediction in parser). "Unbuffered" here refers to fact that it doesn't buffer all data, not that's it's on demand loading of char.

Inheritance: ICharStream

Show file Open project: sharwell/antlr4cs

Public Properties

Property	Type	Description
name	string

Protected Properties

Property	Type	Description
currentCharIndex	int
data	char[]
input	System.IO.TextReader
lastChar	int
lastCharBufferStart	int
n	int
numMarkers	int
p	int

Public Methods

Method	Description
Consume ( ) : void
GetText ( Interval interval ) : string
La ( int i ) : int
Mark ( ) : int	Return a marker that we can release later. Return a marker that we can release later. The specific marker value used for this class allows for some level of protection against misuse where `seek()` is called on a mark or `release()` is called in the wrong order.
Release ( int marker ) : void	Decrement number of markers, resetting buffer if we hit 0.
Seek ( int index ) : void	Seek to absolute character index, which might not be in the current sliding window. Seek to absolute character index, which might not be in the current sliding window. Move `p` to `index-bufferStartIndex` .
UnbufferedCharStream ( ) : System	Useful for subclasses that pull char from other than this.input.
UnbufferedCharStream ( Stream input ) : System
UnbufferedCharStream ( Stream input, int bufferSize ) : System
UnbufferedCharStream ( TextReader input ) : System
UnbufferedCharStream ( TextReader input, int bufferSize ) : System
UnbufferedCharStream ( int bufferSize ) : System	Useful for subclasses that pull char from other than this.input.

Protected Methods

Method	Description
Add ( int c ) : void
Fill ( int n ) : int	Add n characters to the buffer. Returns the number of characters actually added to the buffer. If the return value is less than n , then EOF was reached before n characters could be added.
NextChar ( ) : int	Override to provide different source of characters than input .
Sync ( int want ) : void	Make sure we have 'need' elements from current position p . Last valid `p` index is `data.length-1` . `p+need-1` is the char index 'need' elements ahead. If we need 1 element, `(p+1-1)==p` must be less than `data.length` .

Method Details

Add() protected method

protected Add ( int c ) : void
c	int
return	void

Consume() public method

public Consume ( ) : void
return	void

Fill() protected method

Add n characters to the buffer. Returns the number of characters actually added to the buffer. If the return value is less than n , then EOF was reached before n characters could be added.

protected Fill ( int n ) : int
n	int
return	int

GetText() public method

public GetText ( Interval interval ) : string
interval	Antlr4.Runtime.Misc.Interval
return	string

La() public method

public La ( int i ) : int
i	int
return	int

Mark() public method

Return a marker that we can release later.

The specific marker value used for this class allows for some level of protection against misuse where seek() is called on a mark or release() is called in the wrong order.

public Mark ( ) : int
return	int

NextChar() protected method

Override to provide different source of characters than input .

protected NextChar ( ) : int
return	int

Release() public method

Decrement number of markers, resetting buffer if we hit 0.

public Release ( int marker ) : void
marker	int
return	void

Seek() public method

Seek to absolute character index, which might not be in the current sliding window.

Seek to absolute character index, which might not be in the current sliding window. Move p to index-bufferStartIndex .

public Seek ( int index ) : void
index	int
return	void

Sync() protected method

Make sure we have 'need' elements from current position p . Last valid p index is data.length-1 . p+need-1 is the char index 'need' elements ahead. If we need 1 element, (p+1-1)==p must be less than data.length .

protected Sync ( int want ) : void
want	int
return	void

UnbufferedCharStream() public method

Useful for subclasses that pull char from other than this.input.

public UnbufferedCharStream ( ) : System
return	System

UnbufferedCharStream() public method

public UnbufferedCharStream ( Stream input ) : System
input	Stream
return	System

UnbufferedCharStream() public method

public UnbufferedCharStream ( Stream input, int bufferSize ) : System
input	Stream
bufferSize	int
return	System

UnbufferedCharStream() public method

public UnbufferedCharStream ( TextReader input ) : System
input	System.IO.TextReader
return	System

UnbufferedCharStream() public method

public UnbufferedCharStream ( TextReader input, int bufferSize ) : System
input	System.IO.TextReader
bufferSize	int
return	System

UnbufferedCharStream() public method

Useful for subclasses that pull char from other than this.input.

public UnbufferedCharStream ( int bufferSize ) : System
bufferSize	int
return	System

Property Details

currentCharIndex protected property

Absolute character index.

Absolute character index. It's the index of the character about to be read via LA(1) . Goes from 0 to the number of characters in the entire stream, although the stream size is unknown before the end is reached.

protected int currentCharIndex
return	int

data protected property

A moving window buffer of the data being scanned.

A moving window buffer of the data being scanned. While there's a marker, we keep adding to buffer. Otherwise, consume() resets so we start filling at index 0 again.

protected char[] data
return	char[]

input protected property

protected TextReader,System.IO input
return	System.IO.TextReader

lastChar protected property

This is the LA(-1) character for the current position.

protected int lastChar
return	int

lastCharBufferStart protected property

When numMarkers > 0 , this is the LA(-1) character for the first character in data . Otherwise, this is unspecified.

protected int lastCharBufferStart
return	int

n protected property

The number of characters currently in data .

This is not the buffer capacity, that's data.length .

protected int n
return	int

name public property

The name or source of this char stream.

public string name
return	string

numMarkers protected property

Count up with mark() and down with release() . When we release() the last mark, numMarkers reaches 0 and we reset the buffer. Copy data[p]..data[n-1] to data[0]..data[(n-1)-p] .

protected int numMarkers
return	int

p protected property

0..n-1 index into data of next character.

The LA(1) character is data[p] . If p == n , we are out of buffered characters.

protected int p
return	int