Version française
Home     About     Download     Resources     Contact us    
Browse thread
[Caml-list] format4 query
[ Home ] [ Index: by date | by threads ]
[ Search: ]

[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
Date: -- (:)
From: David J. Trombley <swampy@s...>
Subject: Re: [Caml-list] format4 query

Right, as I said I can get simple examples to work.   But I
can't get syntax such as

 # let g (l : listener) (k : int) fmt =
    match k with
      0 -> 0
    | x -> Printf.kprintf l fmt; k;;

val g : listener -> int -> ('a, unit, string, unit)
format4 -> int = <fun>

to function, as you can see the format type has been
inferred to a type that is not useful at all.

I'd like to use kprintf as a side effect to a function which
evaluates to some type, but I would not like that type or
the unit type of a ; evaluation to affect the format type.

-dj

----- Original Message ----- 
From: "Olivier Andrieu" <andrieu@ijm.jussieu.fr>
To: <swampy@spacebird.net>
Cc: <caml-list@inria.fr>; <hmaon@bumba.net>
Sent: Wednesday, May 19, 2004 3:22 AM
Subject: Re: [Caml-list] format4 query


> David J. Trombley [Wed, 19 May 2004]:
>  >
>  > Suppose I have
>  >
>  > type listener = string -> unit
>  >
>  > which is intended to receive a string type as a value.
>  >
>  > Could someone demonstrate a function that takes a
listener
>  > and a format as arguments, and uses sprintf to obtain a
>  > string, and then calls the listener with the string
>  > argument?
>
> That is precisely what kprintf does.
>
> # type listener = string -> unit;;
> type listener = string -> unit
> # let f (l : listener) fmt = Printf.kprintf l fmt ;;
> val f : listener -> ('a, unit, string, unit) format4 -> 'a
= <fun>
> # f print_endline "%s %d" "abc" 23 ;;
> abc 23
> - : unit = ()
>
> -- 
>    Olivier
>

-------------------
To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr
Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/
Beginner's list: http://groups.yahoo.com/group/ocaml_beginners