org.antlr.runtime

Interface TokenStream

All Superinterfaces:

IntStream

All Known Implementing Classes:

CommonTokenStream, DebugTokenStream, TokenRewriteStream

public interface TokenStream
extends IntStream

A stream of tokens accessing tokens from a TokenSource

Method Summary

Methods

Modifier and Type	Method and Description
Token	get(int i) Get a token at an absolute index i; 0..n-1.
TokenSource	getTokenSource() Where is this stream pulling tokens from? This is not the name, but the object that provides Token objects.
Token	LT(int k) Get Token at current input pointer + i ahead where i=1 is next Token.
String	toString(int start, int stop) Return the text of all tokens from start to stop, inclusive.
String	toString(Token start, Token stop) Because the user is not required to use a token with an index stored in it, we must provide a means for two token objects themselves to indicate the start/end location.

Methods inherited from interface org.antlr.runtime.IntStream

consume, getSourceName, index, LA, mark, release, rewind, rewind, seek, size

Method Detail

LT

Token LT(int k)

Get Token at current input pointer + i ahead where i=1 is next Token. i<0 indicates tokens in the past. So -1 is previous token and -2 is two tokens ago. LT(0) is undefined. For i>=n, return Token.EOFToken. Return null for LT(0) and any index that results in an absolute address that is negative.

get

Token get(int i)

Get a token at an absolute index i; 0..n-1. This is really only needed for profiling and debugging and token stream rewriting. If you don't want to buffer up tokens, then this method makes no sense for you. Naturally you can't use the rewrite stream feature. I believe DebugTokenStream can easily be altered to not use this method, removing the dependency.

getTokenSource

TokenSource getTokenSource()

Where is this stream pulling tokens from? This is not the name, but the object that provides Token objects.

toString

String toString(int start,
              int stop)

Return the text of all tokens from start to stop, inclusive. If the stream does not buffer all the tokens then it can just return "" or null; Users should not access $ruleLabel.text in an action of course in that case.

toString

String toString(Token start,
              Token stop)

Because the user is not required to use a token with an index stored in it, we must provide a means for two token objects themselves to indicate the start/end location. Most often this will just delegate to the other toString(int,int). This is also parallel with the TreeNodeStream.toString(Object,Object).