Aliasing current module qualifier

[Andreas Abel]

The other two work arounds are

1. Explicit import lists for the stuff you need.

2. Explicit export list for your module (which you do), and internally 
use non-overloaded identifiers.

     module AnnoyinglyLongModuleName
        ( AnnoyinglyLongModuleName.length
        , AnnoyinglyLongModuleName.null
        ) where

     length = length'
     null   = null'

     length' :: a -> Int
     length' _ = 0

     null' :: a -> Bool
     null' = (== 0) . length'

On 29.09.2014 10:48, Herbert Valerio Riedel wrote:
> On 2014-09-29 at 10:43:28 +0200, Andreas Abel wrote:
>> Indeed, being able to introduce a short name for the current module,
>> or having a fixed short name like 'This' or 'Self' would be neat.
>>
>> The standard workaround for your example would be
>>
>>    import Prelude hiding (length,null)
>
> That won't work though, because what I failed to mention is that I
> needed this (while avoiding CPP) to cope with external modules growing
> their exports lists, such as Data.Foldable starting to export 'length'
> and 'null' in base-4.8.0.0
>
> Moreover, hiding a non-existent symbol is a warning in recent GHC's but
> a hard error in older GHCs, so that's not an option either if you want
> to avoid CPP, support GHCs back to 7.0, and be -Werror-clean.
>
> More generally, 'hiding'-imports aren't robust in terms of
> forward-compatibility.
>
>>
>> Did you try a .hs-boot file with your self-import trick?
>
> Not yet
>

-- 
Andreas Abel  <><      Du bist der geliebte Mensch.

Department of Computer Science and Engineering
Chalmers and Gothenburg University, Sweden

andreas.abel at gu.se
http://www2.tcs.ifi.lmu.de/~abel/