Package org.antlr.runtime

Interface TokenStream

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method 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.
      int range()
      How far ahead has the stream been asked to look? The return value is a valid index from 0..n-1.
      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.

    • 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.

      • 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).