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Groups > comp.lang.haskell > #478

Re: Typing in Haskell

From Paul Rubin <no.email@nospam.invalid>
Newsgroups comp.lang.haskell
Subject Re: Typing in Haskell
Date 2018-01-07 10:33 -0800
Organization A noiseless patient Spider
Message-ID <87shbh8qnf.fsf@nightsong.com> (permalink)
References <75f33040-0ffd-4442-8e03-6b7177996628@googlegroups.com>

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ivan.moony@gmail.com writes:
> ((is of type x) OR (is of type y)) AND NOT (is of type z)

In Haskell, every term has exactly one (maybe polymorphic or quantified)
type, and that type is known at compile time.  So an expression like the
above makes no sense.  You don't have to test whether thing is of type
x, since you already know.

Maybe you want type classes?  What is an example of something you would
use the feature for?

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Thread

Typing in Haskell ivan.moony@gmail.com - 2018-01-07 01:53 -0800
  Re: Typing in Haskell Paul Rubin <no.email@nospam.invalid> - 2018-01-07 10:33 -0800
    Re: Typing in Haskell ivan.moony@gmail.com - 2018-01-07 12:33 -0800
      Re: Typing in Haskell polymorph self <jackvanc3@gmail.com> - 2018-01-09 14:35 -0800

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