[antlr-interest] expression parser example Expr.g dont work

[Chris Snyder]

stat:   expr NEWLINE 

 

looks like is should just be

 

stat:   expr 

 

The current form hits the '(' and then looks for expr which requires a
NEWLINE after '2' which you don't have.

 

I didn't verify this though.

 

C





  _____  

From: antlr-interest-bounces at antlr.org
[mailto:antlr-interest-bounces at antlr.org] On Behalf Of Mats Ekberg
Sent: Wednesday, January 07, 2009 1:22 AM
To: antlr-interest at antlr.org
Subject: [antlr-interest] expression parser example Expr.g dont work

 

I have stripped the classical expr.g example and when I run it in ANTLRWorks
it dont work.
The input "(1 + 2) * 3 - 4" (with a newline at the end) just recognizes "( 1
+ 2" and the nothing more.
How come?

grammar Expr;

prog:   stat+ ;

stat:   expr NEWLINE 
    |   NEWLINE
    ;

expr
    :   multExpr ( '+' multExpr | '-' multExpr )*
    ;

multExpr 
    :   atom ('*' atom )*
    ; 

atom 
    :   INT 
    |   '(' expr ')'
    ;

INT :   '0'..'9'+ ;
NEWLINE:'\r'? '\n' ;
WS  :   (' '|'\t')+ {skip();} ; 

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