From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr X-Spam-Level: * X-Spam-Status: No, score=1.1 required=5.0 tests=AWL,SPF_NEUTRAL autolearn=disabled version=3.1.3 Received: from mail4-relais-sop.national.inria.fr (mail4-relais-sop.national.inria.fr [192.134.164.105]) by yquem.inria.fr (Postfix) with ESMTP id BEBCABC6B for ; Tue, 6 Nov 2007 19:25:49 +0100 (CET) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AgAAAGFAMEfAXQImh2dsb2JhbACOfwEICik X-IronPort-AV: E=Sophos;i="4.21,379,1188770400"; d="scan'208";a="19004747" Received: from discorde.inria.fr ([192.93.2.38]) by mail4-smtp-sop.national.inria.fr with ESMTP; 06 Nov 2007 19:25:49 +0100 Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83]) by discorde.inria.fr (8.13.6/8.13.6) with ESMTP id lA6IPjqE004732 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=OK) for ; Tue, 6 Nov 2007 19:25:49 +0100 X-IronPort-AV: E=Sophos;i="4.21,379,1188770400"; d="scan'208";a="3964001" Received: from peray.inria.fr (HELO ausone.inria.fr) ([128.93.8.98]) by mail2-relais-roc.national.inria.fr with SMTP; 06 Nov 2007 19:25:48 +0100 Received: by ausone.inria.fr (sSMTP sendmail emulation); Tue, _d Nov 2007 19:25:09 +0100 From: "Nicolas Pouillard" Cc: caml-list Subject: Re: [Caml-list] log function without evaluate arguments To: tmp123 References: <47309EEC.4080706@menta.net> In-Reply-To: <47309EEC.4080706@menta.net> Date: Tue, 06 Nov 2007 19:25:09 +0100 Message-Id: <1194373338-sup-9994@ausone.local> User-Agent: Sup/0.2 Content-Type: text/plain; charset=UTF-8 X-Miltered: at discorde with ID 4730B1A9.000 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)! X-Spam: no; 0.00; kprintf:01 printf:01 val:01 printf:01 fprintf:01 caml-list:01 boolean:01 unit:03 parameters:03 aka:04 tmp:05 implement:06 tue:06 context:06 long:06 Excerpts from tmp123's message of Tue Nov 06 18:05:48 +0100 2007: > Hello, > > In order to implement a function that prints log messages only, by > example, if a boolean flag is true, and does nothing elsewhere, I've > been reading the (long) post sequence "kprintf with user formatters" > (2004 Jun 30). > > In this context, "does nothing" means not convert parameters to text nor > evaluate them. Have a look to the Printf.ifprintf [1] function, it does exactly what you want. Regards, [1]: val ifprintf : 'a -> ('b, 'a, unit) format -> 'b (** Same as {!Printf.fprintf}, but does not print anything. Useful to ignore some material when conditionally printing. *) -- Nicolas Pouillard aka Ertai