Interface TokenSource

  • All Known Implementing Classes:
    ActionAnalysis, ActionTranslator, ANTLRLexer, ANTLRv3Lexer, ANTLRv3Lexer, gUnitLexer, Interpreter, Lexer, StGUnitLexer

    public interface TokenSource
    A source of tokens must provide a sequence of tokens via nextToken() and also must reveal it's source of characters; CommonToken's text is computed from a CharStream; it only store indices into the char stream. Errors from the lexer are never passed to the parser. Either you want to keep going or you do not upon token recognition error. If you do not want to continue lexing then you do not want to continue parsing. Just throw an exception not under RecognitionException and Java will naturally toss you all the way out of the recognizers. If you want to continue lexing then you should not throw an exception to the parser--it has already requested a token. Keep lexing until you get a valid one. Just report errors and keep going, looking for a valid token.
    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      java.lang.String getSourceName()
      Where are you getting tokens from? normally the implication will simply ask lexers input stream.
      Token nextToken()
      Return a Token object from your input stream (usually a CharStream).
    • Method Detail

      • nextToken

        Token nextToken()
        Return a Token object from your input stream (usually a CharStream). Do not fail/return upon lexing error; keep chewing on the characters until you get a good one; errors are not passed through to the parser.
      • getSourceName

        java.lang.String getSourceName()
        Where are you getting tokens from? normally the implication will simply ask lexers input stream.