[plt-scheme] Does anyone use `set!' and `get!' patterns?
Yeah, similar, I'd say. Except that here you're also doing a pattern
match so you have all that going on at the same time.
Robby
On Sun, Mar 9, 2008 at 11:54 AM, Joe Wells <jbw at macs.hw.ac.uk> wrote:
> "Robby Findler" <robby at cs.uchicago.edu> writes:
>
> > No, I don't think so -- get and set patterns aren't just that. They
> > bind mutators and gettors to some place down inside some value.
>
> Is this like Common Lisp setf/getf?
>
> --
> Joe
>
>
>
> > Sam
> > isn't proposing to get rid of the ML-like dereferencing ref cells.
> >
> > Robby
> >
> > On Sun, Mar 9, 2008 at 8:46 AM, Joe Wells <jbw at macs.hw.ac.uk> wrote:
> >> "Sam TH" <samth at ccs.neu.edu> writes:
> >>
> >> > Currently, "plt-match.ss" and scheme/match (in v4) provide `set!' and
> >> > `get!' patterns, which bind mutators and accessors for the matched
> >> > locations, respectively. While these look clever, they complicated the
> >> > implementation of match, and don't seem to be used. In particular,
> >> > I've searched the entire collections hierarchy, and they don't seem to
> >> > be used at all. Given this, I'd like to remove the implementations.
> >> > Does anyone else use them in their code, or have any reason that they
> >> > would want to?
> >>
> >> ML has this feature in pattern matching (in SML a pattern like "ref x"
> >> dereferences a mutable cell and binds its current contents to x). So
> >> presumably PLT can claim to implement a superset of ML pattern
> >> matching. Without this feature, ML fanboys could say "but you don't
> >> have mutator patterns, so our language is better, ha ha ha".
>