RE: Problem in grammar

[Godeau Julien]

Hello,
Thanks for your answer.
You're right, I wanted to simplify the thing and I forgot to put the 'SIGNAL' 
token in signal definition: 

signal : SIGNAL                          { $$ = $2; }
       | '(' signal ')'                  { $$ = $2; }           

       | full_function_call              { $$ = $1; }

       | OPERATOR1 signal %prec UNARY    { $$ = ... }

       | signal OPERATOR1 signal         { $$ = ... }

       | signal OPERATOR2 signal         { $$ = ... }                        

       | signal OPERATOR1 float_value    { $$ = ... }        

       | float_value OPERATOR1 signal    { $$ = ... }    

       | signal OPERATOR2 float_value    { $$ = ... }               

       | float_value OPERATOR2 signal    { $$ = ... }                           
                     

;

"My_other_signal" is seen as a SIGNAL token, being recognized by its name 
thanks to a list of existing signals.
"IDENTIFIER" token is a new name that the system does not know neither for a 
variable nor for a signal.

Julien

-----Message d'origine-----
De : Joel E. Denny [mailto:address@hidden 
Envoyé : dimanche 20 février 2011 16:06
À : Godeau Julien
Cc : address@hidden
Objet : Re: Problem in grammar

On Tue, 15 Feb 2011, Godeau Julien wrote:

> My_var = 3. + 1.
> 
> My_signal = 4. + My_other_signal
> 
> Mysignal = My_other_signal + 4.
> 
>  
> 
> Let's assume that My_var and My_signal are new identifiers, my problem
> is that in the second example the command "Mysignal = 4." is recognized
> by Bison as an integer variable assignment (with parsing error because
> of "My_other_signal") while what should have been done is to recognize
> that "4. + My_other_signal" is a signal (and process it) and then do a
> signal assignment. In the third example, it works fine.

You must have sent us the wrong grammar.  IDENTIFIER can only appear 
before an '=', so the third example (where I assume My_other_signal is an 
IDENTIFIER) should be a syntax error as well.