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Posted By:   Martin_Krueger
Posted On:   Sunday, August 5, 2007 03:25 PM

Hi, I have the following grammer: start: expr ; unary_expr : ('+'|'-')? expr; expr : (NUMBER) (OP expr)?; function: ID '(' param_list ')'; param_list: expr (',' expr)*; ID : ('a'..'z')+; NUMBER : ('0'..'9')+; OP : '+'|'-'|'*'|'/'; I expect that is could parse the expression "1+2", but it does not because of a NoViableAltException when parsing "+", but I don't know why? Greeting, Martin    More>>

Hi,

I have the following grammer:




start: expr ;



unary_expr
: ('+'|'-')? expr;



expr : (NUMBER) (OP expr)?;



function: ID '(' param_list ')';



param_list: expr (',' expr)*;



ID : ('a'..'z')+;

NUMBER : ('0'..'9')+;

OP : '+'|'-'|'*'|'/';



I expect that is could parse the expression "1+2", but it does not because of a NoViableAltException when parsing "+", but I don't know why?



Greeting,
Martin

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