grammar bison(yacc) question

[homeless]

i try to catch the error position, and give out in an error File:


stmnts: primary_terminal exp '\n' {/* read something...*/ }
| primary_terminal error '\n' {/* give out the eror line for exp */; yyerrok;}
| primary_terminal exp error {/* give out the eror line for newline */; yyerrok;}

if i try to give out the errorline for primary_terminal by adding a new opition: error exp '\n' {/* give out the eror line for primary_terminal */; yyerrok;},
so caused the rule stmnts conflicts.

how will that be agreed?

 

[xwb]

You need to break it down further

stmnts:   primary_terminal experr '\n'      {/* read something...*/ }

experr: exp |
        error |
        exp error

I'm not sure if that will work - you may need to break that down even further.

 

[homeless]

thx xwb,

but this was not the answer of my question. think about an input statement like this one:

   if(x>y){...}

with the primary_terminal "if" and

   while(x>y){...}

with the primary_terminal "else"