Packageorg.antlr.runtime
Interfacepublic interface IntStream
SubinterfacesCharStream, TokenStream, TreeNodeStream

A simple stream of integers used when all I care about is the char or token type sequence (such as interpretation).



Public Properties
 PropertyDefined by
  index : int
[read-only] Return the current input symbol index 0..n where n indicates the last symbol has been read.
IntStream
  size : int
[read-only] Only makes sense for streams that buffer everything up probably, but might be useful to display the entire stream or for testing.
IntStream
  sourceName : String
[read-only] Where are you getting symbols from? Normally, implementations will pass the buck all the way to the lexer who can ask its input stream for the file name or whatever.
IntStream
Public Methods
 MethodDefined by
  
consume():void
IntStream
  
LA(i:int):int
Get int at current input pointer + i ahead where i=1 is next int.
IntStream
  
mark():int
Tell the stream to start buffering if it hasn't already.
IntStream
  
release(marker:int):void
You may want to commit to a backtrack but don't want to force the stream to keep bookkeeping objects around for a marker that is no longer necessary.
IntStream
  
rewind():void
Rewind to the input position of the last marker.
IntStream
  
rewindTo(marker:int):void
Reset the stream so that next call to index would return marker.
IntStream
  
seek(index:int):void
Set the input cursor to the position indicated by index.
IntStream
Property detail
indexproperty
index:int  [read-only]

Return the current input symbol index 0..n where n indicates the last symbol has been read. The index is the symbol about to be read not the most recently read symbol.

Implementation
    public function get index():int
sizeproperty 
size:int  [read-only]

Only makes sense for streams that buffer everything up probably, but might be useful to display the entire stream or for testing. This value includes a single EOF.

Implementation
    public function get size():int
sourceNameproperty 
sourceName:String  [read-only]

Where are you getting symbols from? Normally, implementations will pass the buck all the way to the lexer who can ask its input stream for the file name or whatever.

Implementation
    public function get sourceName():String
Method detail
consume()method
public function consume():void
LA()method 
public function LA(i:int):int

Get int at current input pointer + i ahead where i=1 is next int. Negative indexes are allowed. LA(-1) is previous token (token just matched). LA(-i) where i is before first token should yield -1, invalid char / EOF.

Parameters
i:int

Returns
int
mark()method 
public function mark():int

Tell the stream to start buffering if it hasn't already. Return current input position, index(), or some other marker so that when passed to rewind() you get back to the same spot. rewind(mark()) should not affect the input cursor. The Lexer track line/col info as well as input index so its markers are not pure input indexes. Same for tree node streams.

Returns
int
release()method 
public function release(marker:int):void

You may want to commit to a backtrack but don't want to force the stream to keep bookkeeping objects around for a marker that is no longer necessary. This will have the same behavior as rewind() except it releases resources without the backward seek. This must throw away resources for all markers back to the marker argument. So if you're nested 5 levels of mark(), and then release(2) you have to release resources for depths 2..5.

Parameters
marker:int
rewind()method 
public function rewind():void

Rewind to the input position of the last marker. Used currently only after a cyclic DFA and just before starting a sem/syn predicate to get the input position back to the start of the decision. Do not "pop" the marker off the state. mark(i) and rewind(i) should balance still. It is like invoking rewind(last marker) but it should not "pop" the marker off. It's like seek(last marker's input position).

rewindTo()method 
public function rewindTo(marker:int):void

Reset the stream so that next call to index would return marker. The marker will usually be index() but it doesn't have to be. It's just a marker to indicate what state the stream was in. This is essentially calling release() and seek(). If there are markers created after this marker argument, this routine must unroll them like a stack. Assume the state the stream was in when this marker was created.

Parameters
marker:int
seek()method 
public function seek(index:int):void

Set the input cursor to the position indicated by index. This is normally used to seek ahead in the input stream. No buffering is required to do this unless you know your stream will use seek to move backwards such as when backtracking. This is different from rewind in its multi-directional requirement and in that its argument is strictly an input cursor (index). For char streams, seeking forward must update the stream state such as line number. For seeking backwards, you will be presumably backtracking using the mark/rewind mechanism that restores state and so this method does not need to update state when seeking backwards. Currently, this method is only used for efficient backtracking using memoization, but in the future it may be used for incremental parsing. The index is 0..n-1. A seek to position i means that LA(1) will return the ith symbol. So, seeking to 0 means LA(1) will return the first element in the stream.

Parameters
index:int