recmod

recmod

[Anastasia Gornostaeva]

Hello, Happy New Year!

Is it possible to compile such files?

mod1.ml: 
let get a =
   if Mod2.mem a then 1 else 2

mod2.ml:
let mem a = List.mem a [1;2;3]
let other () =
   print_int (Mod1.get 5)

ermine

Re: [Caml-list] recmod

[skaller]

On Fri, 2004-12-31 at 09:38, Anastasia Gornostaeva wrote:

> Is it possible to compile such files?
> 
> mod1.ml: 
> let get a =
>    if Mod2.mem a then 1 else 2
> 
> mod2.ml:
> let mem a = List.mem a [1;2;3]
> let other () =
>    print_int (Mod1.get 5)
> 

No. There is a new experimental feature which provides
some support for intra-module recursion,
but at present the modules must reside
in the same file.

The two common workaround for functions are:

(a) pass Mod2.get to Mod1.get as an argument

(b) create a reference in mod1.ml initialised to 
  
   fun (x:int) -> raise Not_found; 1

   and in mod2.ml store Mod2.get into it, call it in mod1.ml
   by first dereferencing it.

Another technique is to use classes, which automate
the late binding more safely.

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John Skaller, mailto:skaller@users.sf.net
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