Re: Short hand expression operators

[Hans Aberg]

On 25 Mar 2010, at 00:34, Philip Herron wrote:

> I was just thinking until now in my language i haven't allowed
> operators like '++' or '+=' etc. Though in the Lex and Yacc book i
> took the example of using:
>
> '-' express %prec UMINUS
>
> inline with my usual:
>
> exp '+' exp etc, so this allows '-2 + x' and the like. Which i guess
> is half way to allowing: x++ or x-- or x+=2 and the nice short hand
> operators.
>
> Would be nice if you could point me in the right direction of how to
> handle the grammar of these kinds of operators.

Have you tried just adding
  %token PLUSPLUS "++"
  ..
  expr: expr "++"
  ..
etc. with some %prec, possibly %left, %right?

  Hans