antlr-3.4/runtime/CSharp3/Sources/Antlr3.Runtime.Test/SemanticPredicateReduction.g3

grammar SemanticPredicateReduction;

options {
    language=CSharp3;
    TokenLabelType=CommonToken;
}

@lexer::namespace{Antlr3.Runtime.Test}
@parser::namespace{Antlr3.Runtime.Test}

start : mainprog optional? EOF;

mainprog : '(' args ')';
args : ID ID*;

optional: ':'  args element ':' args element2;
element : {true}?=>args2;
element2: {false}?=>args3;
args2 : ID ID*;
args3 : ID ID* ;

WS  : (' '|'\t'|'\n'|'\r')+;
ID  : ('a'..'z')+;