[Haskell] is $ a no-op?
kmillikin at atcorp.com
Wed Oct 13 16:53:19 EDT 2004
On Wednesday, October 13, 2004 11:25 AM, Jacques Carette [SMTP:carette at mcmaster.ca] wrote:
> > > -- It's kind of like an converse map.
> > I have attempted, unsuccessfully, to write flist above in a point-free
> > manner. Is it possible?
> > Of course it is, but why?
> > flist = flip (map . flip ($))
> Some functions are simpler point-free, others are simpler with points. I
> was curious about this one (I like the pointwise version better).
> Also, the statement "It's kind of like a converse map" becomes quite clear
> from the point-free way to write it, while still not so obvious in the
> pointwise version.
I haven't proven it, but I think that this is the same function on lists:
> flist = (. return) . ap
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