Interface TokenStream

All Superinterfaces:
IntStream
All Known Implementing Classes:
BufferedTokenStream, CommonTokenStream, DebugTokenStream, Interp.FilteringTokenStream, LegacyCommonTokenStream, TokenRewriteStream, UnbufferedTokenStream

public interface TokenStream extends IntStream
A stream of tokens accessing tokens from a TokenSource
  • Method Summary

    Modifier and Type
    Method
    Description
    get(int i)
    Get a token at an absolute index i; 0..n-1.
    Where is this stream pulling tokens from? This is not the name, but the object that provides Token objects.
    LT(int k)
    Get Token at current input pointer + i ahead where i=1 is next Token.
    int
    How far ahead has the stream been asked to look? The return value is a valid index from 0..n-1.
    toString(int start, int stop)
    Return the text of all tokens from start to stop, inclusive.
    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 Details

    • 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.
    • range

      int range()
      How far ahead has the stream been asked to look? The return value is a valid index from 0..n-1.
    • 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).