[antlr-interest] Problem with Syntactic Predicate

[David Sweet]

Hello Alexander,

Should your start line read as follows:

start    :    variableDeclaration EOF;

I found that running your grammar ran emitted some "MismatchedToken" 
errors (SEMICOLONS were not expected I guess), but changing 
variableDeclarationPart to variableDeclaration parsed the input test; 
test:Type  and created the AST I sort of expected.

Regards,

David Sweet

Alexander Gängel wrote:
> I just don't get this Syntactic Predicate to work
>
> the Problem is variableDeclaration I just don't see what I'm doing 
> wrong to get Input like:
>
> test; test:Type;test to work.
>
> Alexander
>
> grammar test;
>
> options  {
>    output=AST;
>    ASTLabelType=CommonTree;
>    }
>
> tokens {
>    PATH;
>    Var;
>    Type;
>    TupleType;
>    }
>
> start    :    variableDeclarationPart EOF;
>
> variableDeclaration      :(variableDeclarationPart SEMICOLON )=> 
> variableDeclarationPart SEMICOLON variableDeclaration
>    |variableDeclarationPart
>    ;
>   variableDeclarationPart
>    :Identifier (COLON typeCS)?;
>   typeCS    :
>    (Identifier DOUBLE_COLON )=> Identifier DOUBLE_COLON typeCS 
> ->^(Type ^(PATH Identifier typeCS))
>    |Identifier -> ^(Type ^(PATH Identifier))
>    |tupleTypes -> ^(Type  tupleTypes)
>    ;
>   tupleTypes
>    :
>    'TupleType' '(' variableDeclaration ')' -> ^(TupleType 
> variableDeclaration)
>    ;
>   DOUBLE_COLON
>    :'::';
> COMMA    :',';
> SEMICOLON    :';';
> COLON    :':';
> Identifier    :   ('a'..'z'|'A'..'Z'|'_') (Letter)*;
> fragment
> Letter    :'a'..'z'|'A'..'Z'|'0'..'9'|'_'|'$';
> WS    :  (' '|'\r'|'\t'|'\u000C'|'\n') {$channel=HIDDEN;};
>
>
>