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[Caml-list] inference engine
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Date: -- (:)
From: Remi Vanicat <vanicat@l...>
Subject: Re: [Caml-list] inference engine
skaller <skaller@ozemail.com.au> writes:


[...]

> To do that I'm suggesting to give x the type 'at least an int',
> meaning any subsequent typing of x in the function body
> must be constrainable to int -- and that is checked every time
> additional information is obtained by the inference engine
> to refine the type.
>
> For another example:
>
> 	let f (x:int) = match x with | (a,b) -> ..
>
> should give an error saying:
>
> 	let f (x:int) = match x with | (a,b) -> ..
> 	-------------------------------*****
>
> 	"Here x is used with type 'a * 'b,
> 	which is not compatible with the constraint int"

the error given by ocaml is :

# let f (x:int) = match x with | (a,b) -> 2;;
                                 ^^^^^
This pattern matches values of type 'a * 'b
but is here used to match values of type int


-- 
Rémi Vanicat
remi.vanicat@laposte.net

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