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by popnroll 2925 days ago
getChar is a Haskell function without arguments.
3 comments

In Haskell, getChar isn't a function (something of type a -> b), its type is IO Char

http://hackage.haskell.org/package/base-4.11.1.0/docs/Prelud...

It represents an interaction with the outside world that results in a Char when you perform it. It isn't a function because in Haskell functions must be pure (with no side effects).

This is false. getChar is a constant.
I am confused :S

From your other post: "In both Gluon and Haskell, functions without arguments can be represented as functions over the unit type: f: () -> SomeType"

Isn't `f` a constant here too?, how is this different than getChar? (I get I don't understand something here but not sure what)

`getChar` is not of type `() -> SomeType`, but directly of type `SomeType`.

(Though yes, `f` also is a constant... it's just a constant that happens to be a function, which `getChar` is not.)

I feel the responses to you were somewhat unhelpful. Would they also claim that something of type `MyFun Char` is not a function, where

    data MyFun a = MyFun (() -> Char)
Technically they'd be right.