Python syntax in Lisp and Scheme

[Marco Antoniotti]

David Mertz wrote:
> My answer sucked in a couple ways.
> 
> (1) As Bengt Ricther pointed out up-thread, I should have changed David
> Eppstein's names 'filter' and 'iter' to something other than the
> built-in names.
> 
> (2) The function categorize_compose() IS named correctly, but it doesn't
> DO what I said it would.  If you want to fulfill ALL the filters, you
> don't to compose them, but... well, 'all()' them:
> 
> |    def categorize_jointly(preds, it):
> |        results = [[] for _ in len(preds)]
> |        for x in it:
> |            results[all(filters)(x)].append(x)
> |        return results
> 
> Now if you wonder what the function 'all()' does, you could download:
> 
>     http://gnosis.cx/download/gnosis/util/combinators.py
> 
> But the relevant part is:
> 
>   from operator import mul, add, truth
>   apply_each = lambda fns, args=[]: map(apply, fns, [args]*len(fns))
>   bools = lambda lst: map(truth, lst)
>   bool_each = lambda fns, args=[]: bools(apply_each(fns, args))
>   conjoin = lambda fns, args=[]: reduce(mul, bool_each(fns, args))
>   all = lambda fns: lambda arg, fns=fns: conjoin(fns, (arg,))
> 
> For 'lazy_all()', look at the link.
> 
> See, Python is Haskell in drag.

Come on.  Haskell has a nice type system.  Python is an application of 
Greespun's Tenth Rule of programming.

Cheers
--
Marco




> 
> Yours, David...
> 
> --
> Keeping medicines from the bloodstreams of the sick; food from the bellies
> of the hungry; books from the hands of the uneducated; technology from the
> underdeveloped; and putting advocates of freedom in prisons.  Intellectual
> property is to the 21st century what the slave trade was to the 16th.
>