Table of Contents

Antlr - Channel

About

When you don't want to check for non-semantic rule such as comments / whitespace, you can throw them away with → skip but if you want to preserve them, you use channels.

Syntax

Declaration

Only lexer grammars can contain custom channels specifications 

channels {
  WHITESPACE_CHANNEL,
  COMMENTS_CHANNEL
}

Usage

Those channels can then be used like enums within lexer rules: 

WS : [ \r\t\n]+ -> channel(WHITESPACE_CHANNEL) ;

Built-in