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Re: [Caml-list] Loop times
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Date: -- (:)
From: oliver@f...
Subject: Re: [Caml-list] Loop times
On Mon, Mar 17, 2003 at 02:01:21PM -0800, Daniel M. Albro wrote:
> 
> 	Sorry, I just meant that the version that puts the
> exception into a variable outside of the loop is a win over
> the one that creates the exception inside the loop.

What does this mean for such a version of reading a file
linewise into a list of strings?


let input_lines chan =
  let rec input_lines_helper res =
    let sl = 
       try
         Some (input_line chan) 
       with
         End_of_file -> None in
    match sl with
       None -> List.rev res
     | Some l -> input_lines_helper (l :: res) in
  input_lines_helper []

There is a try-with inside the reacursive function.
But is there a way to avoid it?


Well... I may re-read all the mails and put them together to
one mail or may produce a little paper on that topic?

I have to sort the many new things in FPL-programming
for better understanding....

Or maybe you are interested in collecting all results together
into one conclusion-mail?
(Would be nice. :))


> The
> fastest loop routine overall was the tail recursive loop,
> i.e. the functional/recursive.

BTW: This is new to me. Even OCaml-people told me, that
the imperative version of loops will be faster than
recursive/functional.

That's good news for FP-programming, but that's also 
bad news for people, who want to optimize their
functional programs in speed.


> However, this latest
> imperative version has timing that's very close -- the
> imperative version that pre-builds the exception takes
> just over 28 seconds, and the tail-recursive version
> takes just under 27 seconds.

OK.

Can you give me a short advice on the recursive
Input-function, mantioned above?

Thanks.


Ciao,
   Oliver

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