Re: [Caml-list] weird compilation problem

[Olivier Andrieu <andrieu@ijm.jussieu.fr>]

 Olivier Ricordeau [Saturday 6 September 2003] :
 > Hi!
 > I have a weird compilation problem. ocamlc complains that it doesn't
 > find a class, and I really don't know what mistake I made...
 > FYI, it used to compile fine until I tried to write some interfaces.

 > If someone has an idea of what I did wrong, I'm interested! I'm quite
 > stuck for now.

[ je te l'ai déjà dit mais bon ... ]

You're confusing class specification and class type.

In corpus.ml you define a class, but in corpus.mli you put a class
type. A class type gives a "signature" of a class, listing its methods
and instance variable but a class type doesn't necessarily come with
an implementation (an actual class). So, when you try to use your
Corpus module, you only see a class type and you cannot create an
object with new or define a derived class. What you want is a class
specification.


Class definition (in .ml files) :
 class foo = object method bar = some_expr end

Class specification (in .mli files) :
 class foo : object method bar : some_type_expr end

Class type (in .ml and/or .mli files) :
 class type foo = object method bar : some_type_expr end


Also, you do not really need to write a .mli if you're not hiding
anything from the .ml file.

-- 
   Olivier

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