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Re: Can Haskell compare functions?

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On Saturday, April 7, 2012 8:09:36 AM UTC+1, Paul Rubin wrote:
> ultranewb 
>  writes:
> > I have no idea how dumb this question might be.  I just know the
> > language is "functional," and the type system is "advanced," so I
> > figured an "advanced enough" type system would know all the inputs/
> > outputs of a function to such a degree that it could determine if
> > functions were equivalent.
> >
> > *Main> (\x -> x*0) == (\x -> 0)
> 
> Determining if functions are equivalent is an undecidable problem,
> so Haskell doesn't provide an automatic Eq instance for functions.

Could it at least provide a comparison of function *implementations*? Something like a function pointer comparison in C.

RW

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Can Haskell compare functions? ultranewb <pineapple.link@yahoo.com> - 2012-04-06 23:48 -0700
  Re: Can Haskell compare functions? Paul Rubin <no.email@nospam.invalid> - 2012-04-07 00:09 -0700
    Re: Can Haskell compare functions? Paul Rubin <no.email@nospam.invalid> - 2012-04-07 00:18 -0700
    Re: Can Haskell compare functions? Roman W <bloody_rabbit@gazeta.pl> - 2012-04-18 02:40 -0700
      Re: Can Haskell compare functions? Paul Rubin <no.email@nospam.invalid> - 2012-04-18 22:23 -0700

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