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Types construits et interface de modules
• Sven LUTHER
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 Date: -- (:) From: Sven LUTHER Subject: Types construits et interface de modules
```Bonjour, ...
Hello, ...

est -il possible de faire la chose suivante en caml ?
is it possible to do something like that in caml ?

module type T = sig
type t = A | B
end
module A = struct
type t = A | B
end
module B = struct
type t = A | B | C
end

module F (M:T) = struct
type t = M.t
end

module MA = F (A)
module MB = F (B)

cela ne marche pas car les types t = A | B et t = A | B | C sont
differents
this don't work because the types t = A | B and t = A | B | C are
different

cependant il est possible de faire :

module type T = sig
type t
val a : t
val b : t
end

module A = struct
type t = A | B
let a = A
let b = B
end

module B = struct
type t = A | B | C
let a = A
let b = B
let c = C
end

module F (M:T) = struct
type t = M.t
let a = M.a
let b = M.b
end

module MA = F (A)
module MB = F (B)

en, quoi les constructeurs de types sont-ils differents des fonctions ?
Ils ne sont pas propres a chaque type (en effet dans type t = A | B type
t' = A | C, t'.A ecrase t.A).
Il serait interressant de pouvoir definir automatiquement les
constructeurs dans l'interface du module.

in what are the type constuctors different from function symbols ?
they don't belong only to the corresponding type, but to the whole
module.
it would be nice to be able to define also the type constructors in the
interface of a module.

module A = struct
type t = A |B
end

aurrais le type :
would have the following type :

sig type t val A : t val B : t end

Est ce que cela pose des probleme grave, ou ne s'agit-il que de sucre
syntaxique autour de l'implementation actuelle ?

Would this bring serious problems, or is it just syntaxic sugar over the
actual state of things ?

Amicalement,

Sven LUTHER

```