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[Caml-list] mystified by typing of optional arguments
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Date: -- (:)
From: Francois Thomasset <francois.thomasset@i...>
Subject: Re: [Caml-list] mystified by typing of optional arguments 
> Hi all,
> The following example mystifies me
> 
> let f ?opt x =
>    match opt with
>    | None -> x
>    | Some dx -> x + dx
> 
> let g x = x + 1
> 
> 
> let h1 = function
>    | 0 -> [g]
>    | _ -> [f; g]
> 
> 
> let h2 = function
>    | _ -> [f; g]
> 
> 
> h1 is typable but not h2.
> Why is that ?
You cant' type [f;g] either !
# [ f ; g ];;
This expression has type int -> int but is here used with type
  ?opt:int -> int -> int
While [g;g] is a list of funs
FT



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