Re: [Caml-list] format strings

[John F Carr <jfc@mit.edu>]

Your wrapper returns a function.  Type ‘a, the argument to that function, is determined by the first %-conversion in the format string.  The function returns type ‘b.  If your format argument has one %-conversion, type ‘b will be a string.  If it has more than one, type ‘b will be a function accepting the remaining arguments.

# let g = f “%d %d”;;
val g : int -> int -> string = <fun>
# let h = g 0;;
val h : int -> string = <fun>
# h 1;;
- : string = "0 1"

In the past partial application of printf family functions hasn’t worked well, so test before relying on behavior of the returned function.

> On Feb 9, 2015, at 06:58 , Jiten Pathy <jpathy@fssrv.net> wrote:
> 
> When i define a wrapper around format functions like
> 
> let f s = (fun x -> Printf.sprintf s x);;
> 
> val f : ('a -> 'b, unit, bytes) format -> 'a -> 'b = <fun>
> 
> I am confused about the inferred type. where does this 'b comes from?
> 
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