[Python-ideas] Predicate Sets

[David Mertz]

Isn't that exactly what I suggested up-thread with my suggested small
library of combinators? E.g.:

  def allP(*fns):
        return lambda x: all(f(x) for f in fns)

I like encapsulating it better since it encourages naming such combined
functions, e.g.:

  this_and_that = allP((this, that))

I feel like that encourages reuse and readability when one later wants to
write:

  set_with_predicate = {x for x in baseset if this_and_that(x)}

Or:

  if this_and_that(x): ...



On Tue, Jan 21, 2014 at 1:09 AM, Serhiy Storchaka <storchaka at gmail.com>wrote:

> 21.01.14 10:58, Haoyi Li написав(ла):
>
>>  > *all(map(list_of_filters, value))*
>>
>>
>> Scratch that, what I actually want is
>>
>> *all(map(lambda f: f(value), list_of_filters))*
>> *
>> *
>> I always mix up the order of things going into *map* =(*
>> *
>>
>
>     all(f(value) for f in list_of_filters)
>
> looks cleaner to me.
>
> Perhaps slightly more efficient (but much less readable) form:
>
>     all(map(operator.methodcaller('__call__', value), list_of_filters)
>
>
>
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