[Haskell-cafe] Proposal: Shorter Import Syntax

Kosyrev Serge _deepfire at feelingofgreen.ru
Wed Jun 3 21:11:20 UTC 2015


Anthony Cowley <acowley at seas.upenn.edu> writes:
> On Wed, Jun 3, 2015 at 2:45 PM, Kosyrev Serge
> <_deepfire at feelingofgreen.ru> wrote:
>> Then wouldn't it also make sense to also:
>>
>>   1. eliminate the arguably confusing double-import through as-without-qualified:
>>
>>        import FQMN as M .. (which imports the exportlist of FQMN twice)
>>
>>      Does a lot of code use that?  Is this a good practice?  Do we want
>>      to encourage this kind of usage?
>>
>>   2. and take advantage of the reduced complexity by implying
>>      "qualified", wheneved "as" is present, by replacing:
>>
>>        import qualified FQMN as M …
>>
>>      with
>>
>>        import FQMN as M …
>>
>>   3. effectively drop the "qualified" keyword from use (can be done lazily)
>>
>> It would break things, though.
>>
>
> This (2) is what I would want to do, too, ideally. However, the
> breakage really makes it inviable.
>
> I tried to quantify the use of the other syntax in another email. I
> grepped through the source of all the packages in the Stackage Nightly
> package set and found that less 0.3% of imports use that syntax. It's
> a small number, but it's not zero, so the breakage would be
> unacceptable.

One can look at it this way -- the breakage is a fixed, one-time cost,
whereas the confusion has a running cost.

So in the end, the real question is what is our planning horizon.


-- 
respectfully,
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