From: Olivier Roussel <olivier.roussel@crans.org>
To: YC <yinso.chen@gmail.com>
Cc: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] best and fastest way to read lines from a file?
Date: Mon, 01 Oct 2007 23:55:58 +0200 [thread overview]
Message-ID: <47016CEE.8010704@crans.org> (raw)
In-Reply-To: <779bf2730710011427g5983da4cw6ad8b715a9e38771@mail.gmail.com>
YC a écrit :
> Hi all -
Hi!
> OCaml code:
> (* test.ml <http://test.ml> *)
> let rec line_count filename =
> let f = open_in filename in
> let rec loop file count =
> try
> ignore (input_line file);
> loop file (count + 1)
> with
> End_of_file -> count
> in
> loop f 0;;
>
> let count = line_count <345k-line.txt> in
> Printf.printf "Done: %d" count;;
The following solution is ~2.5x faster than the Python implementation on
my computer. Because there is no more exceptions in recursive calls, and
thanks to tail-recursion.
let readline f =
try Some (input_line f)
with End_of_file -> None;;
let line_count filename =
let f = open_in filename in
let rec loop count =
match (readline f) with
| Some(_) -> loop (count+1)
| None -> count in
loop 0;;
let count = line_count <345k-line.txt> in
Printf.printf "Done: %d\n" count;;
--
Olivier Roussel
next prev parent reply other threads:[~2007-10-01 21:55 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-01 21:27 YC
2007-10-01 21:55 ` [Caml-list] " Daniel Bünzli
2007-10-01 22:29 ` YC
2007-10-01 21:55 ` Olivier Roussel [this message]
2007-10-02 12:39 ` Mattias Engdegård
2007-10-02 12:56 ` Brian Hurt
2007-10-02 16:15 ` kirillkh
2007-10-02 17:10 ` verlyck, Bruno.Verlyck
2007-10-02 18:02 ` kirillkh
2007-10-02 19:35 ` skaller
2007-10-02 21:05 ` kirillkh
2007-10-02 21:07 ` Jon Harrop
2007-10-02 20:23 ` Olivier Andrieu
2007-10-02 20:49 ` kirillkh
2007-10-02 21:10 ` Jon Harrop
2007-10-02 21:15 ` David Allsopp
2007-10-02 22:23 ` skaller
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