Re: Proposal: unify constant functors

On 4/30/12 8:05 AM, Andreas Abel wrote:

On 30.04.12 1:56 PM, Ross Paterson wrote:

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On Mon, Apr 30, 2012 at 10:55:51AM +0100, Bas van Dijk wrote:

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On 30 April 2012 07:33, wren ng thornton wrote:

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(1) add the Foldable and Traversable instances to base, and

+1

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(2) deprecate transformers:Data.Functor.Constant

I assume you want to re-export Control.Applicative.Constant from Data.Functor.Constant and deprecate the whole module as in:

module Data.Functor.Constant {-# DEPRECATED "Import Constant from Control.Applicative instead" #-} ( Constant(..) ) where

import Control.Applicative

Not quite, as the one in Control.Applicative is called Const and the one in Data.Functor.Constant is called Constant. I slightly prefer the full name. Maybe just move Data.Functor.Constant into base (removing the copy in Control.Applicative)?

I'd second that. All I get from Const in Control.Applicative is import conflicts. The full name, 'Constant' is better.

I rather prefer the short name m'self. Where do you get the import conflicts from? For the record, I'd be fine with moving Data.Functor.Constant to base (I rather prefer that as the module name, as opposed to exporting it from Control.Applicative), I was just proposing the smallest change that would resolve the duplication. -- Live well, ~wren