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Re: Is there a function that applies list of functions to a value?

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On Friday, August 30, 2013 8:36:40 AM UTC+2, alex23 wrote:
> On 30/08/2013 4:17 PM, fp2161@gmail.com wrote:
> 
> > On Wednesday, August 28, 2013 8:50:53 PM UTC+2, Josh English wrote:
> 
> >> def compose(*funcs):
> 
> >>      for func in funcs:
> 
> >>          if not callable(func):
> 
> >>              raise ValueError('Must pass callable functions')
> 
> 
> 
> > Imho still, the ValueError you are raising is not that important in this context, it would raise an Error anyway.
> 
> 
> 
> The main advantage with Josh's approach is that it fails at the point of 
> 
> composition, not when the composed function is first used.  It'd be even 
> 
> more useful if it aggregated a list of the failing functions and 
> 
> returned their names as part of the error.
> 
> 
> 
> Personally, I'd go with an assertion:
> 
> 
> 
>      assert all(map(callable, funcs)), "Must pass callable functions"
> 
> 
> 
> I find that it makes it more obvious that this is part of the function 
> 
> contract rather than the actual body.

it is a valid point, but I would contend that it makes this quick and easy code a little bit heavy just for the sake of ensuring that you are composing composable functions... The assertion is definitely better.

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Thread

Is there a function that applies list of functions to a value? AdamKal <adamkalinski@gmail.com> - 2013-08-28 05:52 -0700
  Re: Is there a function that applies list of functions to a value? Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-08-28 16:10 +0300
    Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 15:48 -0700
  Re: Is there a function that applies list of functions to a value? Tim Chase <python.list@tim.thechases.com> - 2013-08-28 08:11 -0500
    Re: Is there a function that applies list of functions to a value? Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-08-28 16:19 +0300
    Re: Is there a function that applies list of functions to a value? AdamKal <adamkalinski@gmail.com> - 2013-08-28 06:23 -0700
      Re: Is there a function that applies list of functions to a value? Chris Angelico <rosuav@gmail.com> - 2013-08-28 23:26 +1000
      Re: Is there a function that applies list of functions to a value? Tim Chase <python.list@tim.thechases.com> - 2013-08-28 08:43 -0500
        Re: Is there a function that applies list of functions to a value? AdamKal <adamkalinski@gmail.com> - 2013-08-28 06:50 -0700
  Re: Is there a function that applies list of functions to a value? ishish <ishish@domhain.de> - 2013-08-28 14:17 +0100
  Re: Is there a function that applies list of functions to a value? Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2013-08-28 15:09 +0200
  Re: Is there a function that applies list of functions to a value? Josh English <Joshua.R.English@gmail.com> - 2013-08-28 11:50 -0700
    Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 23:17 -0700
      Re: Is there a function that applies list of functions to a value? alex23 <wuwei23@gmail.com> - 2013-08-30 16:36 +1000
        Re: Is there a function that applies list of functions to a value? Fabrice Pombet <fp2161@gmail.com> - 2013-08-30 01:11 -0700
  Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 13:50 -0700
    Re: Is there a function that applies list of functions to a value? Chris Angelico <rosuav@gmail.com> - 2013-08-30 07:05 +1000
      Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 14:27 -0700
        Re: Is there a function that applies list of functions to a value? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-30 02:18 +0000
        Re: Is there a function that applies list of functions to a value? Chris Angelico <rosuav@gmail.com> - 2013-08-30 07:35 +1000
          Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 23:14 -0700
            Re: Is there a function that applies list of functions to a value? alex23 <wuwei23@gmail.com> - 2013-08-30 16:23 +1000
              Re: Is there a function that applies list of functions to a value? Fabrice Pombet <fp2161@gmail.com> - 2013-08-30 01:06 -0700
      Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 14:48 -0700
        Re: Is there a function that applies list of functions to a value? Terry Reedy <tjreedy@udel.edu> - 2013-08-30 00:38 -0400
    Re: Is there a function that applies list of functions to a value? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-30 02:09 +0000
      Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 23:06 -0700

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