Re: [Caml-list] Curried form different from "normal"

[Jon Harrop <jon@ffconsultancy.com>]

On Sunday 05 February 2006 16:40, Till Varoquaux wrote:
>  let non_blank_string=
>       if !is_first then
> 	trailling:=Buffer.contents white
>       else
> 	Buffer.add_buffer buf white;
>       Buffer.reset white;
>       is_first:=false;
>       Buffer.add_string buf
>
>  let non_blank_string s=
>       if !is_first then
> 	trailling:=Buffer.contents white
>       else
> 	Buffer.add_buffer buf white;
>       Buffer.reset white;
>       is_first:=false;
>       Buffer.add_string buf s
>
> Doesn't yeld the same results (the former is buggy). Now, as I
> understand, these two functions should be exactly equivalent. I am
> misunderstanding something here?

The code preceding the call to "Buffer.add_string" is only evaluated once in 
the former case (at the time of definition) whereas it is evaluated at each 
invocation of the latter definition of "non_blank_string".

You should not have expected these two definitions to be "exactly equivalent" 
as the former is equivalent to:

 if !is_first then
   trailling:=Buffer.contents white
 else
   Buffer.add_buffer buf white;;

 Buffer.reset white;;

 is_first:=false;;

 let non_blank_string =
      Buffer.add_string buf

-- 
Dr Jon D Harrop, Flying Frog Consultancy Ltd.
Objective CAML for Scientists
http://www.ffconsultancy.com/products/ocaml_for_scientists