Re: strange error

[Etienne Gagnon <gagnon.etienne_m@uqam.ca>]

pieter@West.NL wrote:
> I get a strange error in the following grammar:
> Tokens
> 	star   = '*';
> 	plus   = '+';
> 	semi   = ';';
> 	int    = (['0'..'9'])+;
> 	blank  = (' ' | 13 | 10 | 9)+;
>
> Ignored Tokens
> 	blank;
>
> Productions
> 	expr  = mexpr (plus mexpr)* semi;
>
> 	mexpr = atom (star atom)*;
>
> 	atom  = int;

You are using parentheses; this is not supported (see documentation and past
mailing-list discussions).


Anyway, you are writing your grammar the as if you didn't have an LALR
parser.

You probably want to write:

prog = expr semi;

expr =
  {plus} expr plus mexpr |
  {mexpr} mexpr;

mexps =
  {star} mexpr star atom |
  {atom} atom;

atom = int;


Etienne

--
Etienne M. Gagnon, Ph.D.             http://www.info.uqam.ca/~egagnon/
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