Message-Id: <9606140921.AA32629@idse.heidelbg.ibm.com>
To: Bouzid Djamila <Bouzid.Djamila@loria.fr>
Subject: Re: Probleme d'interface
In-Reply-To: (Your message of Thu, 13 Jun 96 18:45:33 O.)
<199606131645.SAA17944@delsarte.loria.fr>
Date: Fri, 14 Jun 96 11:21:04 +0100
From: Wolfgang Lux <lux@heidelbg.ibm.com>
Bouzid Djamila <Bouzid.Djamila@loria.fr> writes:
>
> Hi!
>
> I have two CSL files : vendor.mli (the interface) and vendor.ml
>
> (* vendor.mli *)
> module type VENDOR_INTEGER =
> sig
> val min : int * int -> int
> end (* sig *)
>
> module type VENDOR =
> sig
> val print: string -> unit
> module Integer : VENDOR_INTEGER
> end (* sig *)
>
>
> (*vendor.ml *)
> open vendor
> module V : VENDOR =
> struct
> let print = print_string
> module Integer : VENDOR_INTEGER =
> struct
> let min ((x:int),(y:int)) = if x < y then x else y
> end
> end (* functor V *)
>
> when compiling these programs, I receive the following error message :
>
> finot ip 175 % cslc -i vendor.mli
> module type VENDOR_INTEGER = sig val min : int * int -> int end
> module type VENDOR =
> sig val print : string -> unit module Integer : VENDOR_INTEGER end
> finot ip 176 % cslc -i vendor.ml
> module V : Vendor.VENDOR
> The implementation vendor.ml does not match the interface vendor.cmi:
> The field `VENDOR' is required but not provided
> The field `VENDOR_INTEGER' is required but not provided
> finot ip 177 %
>
> Please, could you tell me where's the problem ?
>
The problem simply is, that you have to define both modules types
VENDOR_INTEGER and VENDOR in vendor.ml as well to compile.
But actually this is not what you really want, as the local module V
is not visible at all outside of vendor.ml! (And in contrary to your
comment it is not a functor!)
If you look into the Caml Special Light reference, you will see that
the files vendor.mli and vendor.ml constitute themselves a module
which is roughly equivalent to
module Vendor :
sig
<<contents of vendor.mli>>
end =
struct
<<contents of vendor.ml>>
end
So you wanted probably to write the following module interface vendor.mli:
module type VENDOR_INTEGER =
sig
val min : int * int -> int
end (* sig *)
val print: string -> unit
module Integer : VENDOR_INTEGER
And your implementation vendor.ml then would look as follows:
module type VENDOR_INTEGER =
sig
val min : int * int -> int
end
let print = print_string
module Integer : VENDOR_INTEGER =
struct
let min ((x:int),(y:int)) = if x < y then x else y
end
Hope this helps,
Wolfgang
----
Wolfgang Lux
WZH Heidelberg, IBM Germany Internet: lux@heidelbg.ibm.com
+49-6221-59-4546 VNET: LUX at HEIDELBG
+49-6221-59-3500 (fax) EARN: LUX at DHDIBMIP