org.antlr.runtime

Interface TokenSource

All Known Implementing Classes:

Lexer

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

Methods

Modifier and Type	Method and Description
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

String getSourceName()

Where are you getting tokens from? normally the implication will simply ask lexers input stream.