Re: (define-module (foo) #:import (...)), a la r6rs

[Andy Wingo]

Heya Ludo,

Ping :)  You still against changes to define-module?  I'm OK with that,
but I just wanted to get an explicit reaction.  Too much mail over the
last month, eh :-)

Andy

On Tue 06 Dec 2011 12:30, Andy Wingo <address@hidden> writes:

> On Thu 10 Nov 2011 00:50, address@hidden (Ludovic Courtès) writes:
>
>> Andy Wingo <address@hidden> skribis:
>>
>>> On Thu 28 Jul 2011 23:23, address@hidden (Ludovic Courtès) writes:
>>>
>>>> Andy Wingo <address@hidden> skribis:
>>>>
>>>>>   (define-module (foo)
>>>>>     #:import ((bar)
>>>>>               (only (baz) qux foo)
>>>>>               ...))
>>>>>
>>>>> Or even:
>>>>>
>>>>>   (define-module (foo)
>>>>>     (import (bar)
>>>>>             (only (baz) qux foo)
>>>>>             ...))
>>>>
>>>> I’d prefer #:use-modules (plural), for consistency:
>>>>
>>>>   (define-module (foo)
>>>>     #:use-modules ((bar)
>>>>                    (baz) #:select (qux foo)
>>>>                    (chbouib) #:renamer (symbol-prefix-proc 'p)))
>>>
>>> I don't like the paren placement so much.  Consistency is important, but
>>> TBH I think that we should phase out the "use-module" / "use-modules"
>>> terminology, in favor of "import" terminology of r6rs and the coming
>>> r7rs.
>>
>> I find aesthetics important, but phasing out such an important construct
>> “just” for aesthetics seems harsh to me.
>
> Yeah, but it is not simply aesthetics: it is consistency with other
> schemes, `import' is the natural converse of `export', and the important
> cases of "import only these bindings", "rename these particular
> bindings", and "import this module with a prefix" are really easy in the
> r6rs import language.
>
>> Besides, stuff like #:renamer is strictly more powerful than what
>> R[67]RS provide, IIRC.
>
> No argument there!  But I rarely use it.  Even #:select is a bit of a
> PITA to use:
>
>   #:use-module ((a) #:select (b c d))
>   #:use-module ((e) #:renamer (symbol-prefix-proc 'p:))
>
> vs
>
>   (import (only (a) b c d)
>           (prefix (e) p:))
>
> In particular the #:use-module variant has non-obvious paren placement
> for #:select two places: the wrapper for the whole form, and the list of
> bindings.  And of course #:renamer would still be there for you to
> use. if you wanted to.
>
> Dunno, I still think this would be a good idea, but I think we would
> need to come to agreement first.
>
> Andy

-- 
http://wingolog.org/