I like this idea. How about some more syntactic sugar? {-# LANGUAGE ImportSugar #-} import [Data.[Text, Foldable q-as F, Vector (Vector), Vector q-as V hiding (Vector)], Control.Concurrent, Data.List q (sum)] - tree structure, one import per leaf - prefix qualified -> postfix q - qualified/as -> q-as or q as or q/as or qas

Gesendet: Mittwoch, 01. Februar 2017 um 16:34 Uhr Von: "Francesco Ariis" An: haskell-prime@haskell.org Betreff: Re: Multiple imports on a single line

On Wed, Feb 01, 2017 at 04:18:13PM +0200, Vassil Ognyanov Keremidchiev wrote:

...

Hello!

What do you think about an idea to have multiple imports on a single line, like:

module MyApp where import Data.Text, Data.Foldable, Control.Concurrent ...

Hello Vassil, how would qualified/as work? Would import statement like this:

import Data.Text, qualified Data.Foldable as F, Control.Concurrent

be allowed?

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The main annoying thing in import lists for me at the moment is the proliferation of modules which one would like to import both qualified under some alias and to import a handful of names unqualified (especially infix functions and types). It would be nice if rather than import qualified Data.Map as Map import Data.Map (Map) import qualified Data.Sequence as S import Data.Sequence (Seq, ViewR(..), ViewL(..), (<|), (|>)) we could instead have some variation like: import Data.Map qualified as Map, (Map) import Data.Sequence qualified as S, (Seq, ViewR(..), ViewL(..), (<|), (|>)) I'm thinking something along the lines of the following: *impdecl* -> import *modid impspec_1, impspec_2, ..., impspec_*n (n >= 0) *impspec* -> ( *import*_1, ..., *import*_n [,] ) [*impqual*] (n >= 0) | *impqual* *impqual* -> [qualified] as *modid* [*imphiding*] | *imphiding* *imphiding* -> hiding (*import*_1, ..., *import*_n [,] ) (n >= 0) I haven't thought particularly hard about this BNF, though hopefully it gets across my idea. You'd also certainly want to mix in support (perhaps with deprecation?) for the existing syntax which places the 'qualified' before the module identifier, even though I've personally always found that awkward, as it makes imports hard to read and sort. The other thing which would greatly ameliorate the annoyance with import lists would be the ability to import and then re-export modules in a way that retains the manner in which things were qualified. So one could, if one wanted, have a module which imports things like Map, Set, (lazy and strict) Text, (lazy and strict) ByteString, etc. re-exported qualified the way one wants, and then import that from the other modules in the project. On Wed, Feb 1, 2017, 10:36 Francesco Ariis wrote: On Wed, Feb 01, 2017 at 04:18:13PM +0200, Vassil Ognyanov Keremidchiev wrote:

Hello!

What do you think about an idea to have multiple imports on a single line, like:

module MyApp where import Data.Text, Data.Foldable, Control.Concurrent ...

Hello Vassil, how would qualified/as work? Would import statement like this: import Data.Text, qualified Data.Foldable as F, Control.Concurrent be allowed? _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-prime

Yes, but it could be a bit more denser without so much repetition of "import", like: import Data.Text, qualified Data.Map as M, qualified Vector as V hiding (Vector) i.e. the same as current situation, but allow for multiple imports for the same word "import" comma separated. What do you think? The difference in syntax is not so much different, than just allowing commas. 2017-02-01 23:23 GMT+02:00 Malcolm Wallace :

You can already write this, with only a tiny bit of syntax:

module MyApp where import Data.Text; import Data.Foldable; import Control.Concurrent

Whether it is good style is another matter, but all compilers will certainly accept it.

Regards, Malcolm

On 1 Feb 2017, at 14:18, Vassil Ognyanov Keremidchiev wrote:

Hello!

What do you think about an idea to have multiple imports on a single line, like:

module MyApp where import Data.Text, Data.Foldable, Control.Concurrent ...

That way we could write more concise and short code as Haskell promises. This will be useful for small programs like scripts, small tools, tutorials, examples, etc.

Best regards, Vassil Keremidchiev _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-prime

Sven Panne writes:

I often see a confusion between greater expresiveness (good goal) and having to type less (largely irrelevant goal). By all means make the module system more expressive, but try to avoid "clever" things for convenience.

+1 -- Jón Fairbairn Jon.Fairbairn@cl.cam.ac.uk