Re: [Chicken-users] What is the purpose of module interfaces?

[Felix]

From: Matt Gushee <address@hidden>
Subject: Re: [Chicken-users] What is the purpose of module interfaces?
Date: Tue, 16 Oct 2012 17:37:53 -0600

> On Tue, Oct 16, 2012 at 5:18 PM, Kon Lovett <address@hidden> wrote:
> 
>>
>> On Oct 16, 2012, at 4:11 PM, Matt Gushee wrote:
>>
>> > I am trying to understand the usage of module interfaces
>>>
>>
>>
>>
>>>
>>> The 'functor' facility is for generic programming.
>>
>> documented? The page on modules in the manual makes no explicit
>> association between interfaces and functors. Indeed, I don't see any hint
>> that interfaces can be used in functor definitions the way you do in your
>> egg.
>>
>>
>> See http://wiki.call-cc.org/man/4/Modules.html#functors
>>
>> Buried at the bottom.
>>
> 
> Oh, okay, I see it now. I had skimmed the functors section, but missed the
> sentence referring to DEFINE-INTERFACE.  I still think the doc could stand
> to be clarified a bit--e.g., with a specific example of using an interface
> in a functor definition. I would imagine many people are unfamiliar with
> functors, especially those who have not programmed in other functional
> languages. Though the part about interfaces is a fairly minor detail,
> sometimes confusion about the little things can get in the way of
> understanding the important concepts.

Quite correct - the "Functors" section in the manual is more than
insufficient. I was happy enough just getting that stuff to work
(somewhat) and sometimes the words just don't flow out that easily
when writing the documentation, so in the end I can come out with just
the bare minimum. The test-suite in the chicken tarball contains a
slightly less ridiculuous example, in particular "functor-tests.scm",
"QUEUE.scm", "breadth-first.scm" and "test-queue.scm".

Would you perhaps like to help us with this by extending this manual
section a little? You could take that queue example as a starting
point and explain things alongside the code. That would be nice, and
certainly helpful to new users, or users new to this feature.


cheers,
felix