Re: [Caml-list] camlimages vs. labltk

[Sven Luther <luther@dpt-info.u-strasbg.fr>]

On Wed, Mar 26, 2003 at 12:24:56PM +0100, Alessandro Baretta wrote:
> 
> 
> Sven Luther wrote:
> >On Wed, Mar 26, 2003 at 10:00:03AM +0100, Alessandro Baretta wrote:
> >
> >>
> >>Sven Luther wrote:
> 
> >>Sven, someone on this list wisely pointed out that you buy 
> >>nothing by telling someone else "You don't need that 
> >>feature". We do need namespaces. It might not be paramount: 
> 
> >As for side-effects, i didn't really think about that, but i guess that
> >you could easily implement the modules so that the side effect do happen
> >when you call a module initialization function or something such. I
> >don't think it really is good practice to use toplevel global side
> >effect for library code anyway.
> 
> We now have a new language feature: it's called
> You Don't Need It (TM), patent pending ;)

Hey, you don't need to be sarcastic.

Tell me a legitimate reason to use side-effects in library top-level
would you, especially if you think that such a library may in the future
be shared, dynamically loaded and such.

> >>So -pack is good, but 
> >>namespaces are still a necessary feature to Ocaml as to any 
> >>industrial level programming language.
> >
> >
> >No, the namespace feature is already there, altough not much used in
> >reality, the problems are elsewhere.
> 
> Modules are a very powerful theoretical instrument with a 
> profound algebraic meaning, rooted in category theory. This 
> is all very good, and I appreciate it. But namespaces are 
> something _ELSE_. And they too are a good thing to have. Why 
> don't we just stop this "You don't need it thing" about any 
> language feature we don't already have. Ocaml is a cool 
> language. It's my primary language for developing business 
> applications. I earn a living with it. I know what I need 
> and what I don't need. Namespaces are a useful tool, aside 
> from the algebraically based module system: they simply 
> provied a means for mangling module names so as to avoid 
> name clashes.

So please tell me, what is it that namespace give you that the module
system don't provide already ? And what is the point in mangling module
names ? Do you really prefer a LabltkImage module over Labltk.Image ?
Which one makes more sense to you ?

> There are many different ways of implementing a namespace 
> system. We need to think of an implementation orthogonal to 
> the module system, so as to add functionality without 
> introducing conflicts with the module system. I would 
> appreciate a lot more a -namespace option to ocamlmklib than 
> a -pack option to ocamlc. This feature would have to go with 

Ok, you would want to have the pack option done at library generation
time, i agree with you, i don't really like the way it is currently done
(to generate a huge .cmo from multiple ones), and much would prefer to
have a .cma generated from multiple .cmo, with the -pack option (or the
-namespace, or whatever you would call it). Ideally, this would be the
default, so we would not have to worry about libraries not doing it.

> such additional language constructs such as an "in" operator 
> for namespace resolution. Such language constructs have 

What about the '.' ? Like in Labltk.Image ?

> already been implemented as camlp4 syntax extensions and are 
> already available out there.

Sure, but this is just syntax, what is important here is not so much
what you call it, but what it does.

Friendly,

Sven Luther

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