On Tue, 2002-09-03 at 11:35, Ken Fox wrote:
> Peter Haworth wrote:
> > Also the different operators used (:= inside the rule, = inside the code)
> > seems a bit confusing to me; I can't see that they're really doing anything
> > different:
> >
> > / $x := (gr\w+) / vs / (gr\w+) { let $x = $1 } /
> >
> > Shouldn't they both use C< := > ?
>
> Depends on what you want. The "$x :=" in the rule binds the
> first match to $x -- it does not copy the value. The "$x ="
> in the code block copies the value of the first match. You
> can use either binding or assignment in the code block.
Hmm... I had not thought of the copy aspect. Certainly, the code version
is more flexible. You could define C<$x> above as anything. For example:
/ (gr\w+) {let $x = Gr_Thing.new($1)} /
The binding version is just a simple, fast version of one special case,
no?
