From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: tomas@tuxteam.de Newsgroups: gmane.lisp.guile.user Subject: Re: Writing a procedure in different style Date: Mon, 21 Dec 2020 13:31:48 +0100 Message-ID: <20201221123147.GC3816@tuxteam.de> References: <3760549b-b32f-fafc-1291-8e3eda7b3753@posteo.de> <2d6f348c-1e43-a5c4-1998-baa04b91bf8c@gmail.com> <1385bd6a-c14e-76f1-6dfe-4cf50d192375@gmail.com> <33683c10-5e29-8e4a-03a4-64852fbcf474@posteo.de> <20201213142412.GB6620@tuxteam.de> <66a4948b-6c35-d9df-daa0-865956f52821@posteo.de> <20201213154300.GC6620@tuxteam.de> <93cfbdc6-a013-d6c8-15a7-b2d2feb2455a@posteo.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="kVXhAStRUZ/+rrGn" Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="26798"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mutt/1.5.21 (2010-09-15) Cc: guile-user@gnu.org To: Zelphir Kaltstahl Original-X-From: guile-user-bounces+guile-user=m.gmane-mx.org@gnu.org Mon Dec 21 13:32:15 2020 Return-path: Envelope-to: guile-user@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1krKMJ-0006sN-Ij for guile-user@m.gmane-mx.org; Mon, 21 Dec 2020 13:32:15 +0100 Original-Received: from localhost ([::1]:38270 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1krKMI-0008GX-GV for guile-user@m.gmane-mx.org; Mon, 21 Dec 2020 07:32:14 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:42074) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1krKM5-0008GO-RK for guile-user@gnu.org; Mon, 21 Dec 2020 07:32:01 -0500 Original-Received: from mail.tuxteam.de ([5.199.139.25]:47372) by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.90_1) (envelope-from ) id 1krKM1-0002iN-Jw for guile-user@gnu.org; Mon, 21 Dec 2020 07:32:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tuxteam.de; s=mail; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date; bh=imTizgawm4F9qeyQAz9hkeD7hJ420/oO7ILvouO8qAs=; b=oIpIqfz/46Tm3BgTU/ygQT+yYBoDg1u27e8opX9VkRqIBBMuzrlJ/U9zJy9ZM0V+sFB+eEhVY+auzu0gl8b42u2nr1qHw4RPfprG//itHC2Orr/Yz3Mz7ANSJZlTmiPjbo2nx8GADbZ3Zi1TP4rQWBeWq5O8I0z8/al/+ozj+PjZlH9Vo4RMrHJXQVVd1xHBvwT4omBWfV+3C3pZD5nyQM4OeogFRLk+s7/6V3c3XKfGVDH5poXSVsFipaJjwVBEQXodQxH4qGOjs6HNiytquYHf8r6HKnfVX5hQBznCBNr60O3nfjnK7vb2IOUjPUKAd4Lpp2aZexM7av99kSQxkw==; Original-Received: from tomas by mail.tuxteam.de with local (Exim 4.80) (envelope-from ) id 1krKLs-0003Pp-1Z; Mon, 21 Dec 2020 13:31:48 +0100 Content-Disposition: inline In-Reply-To: <93cfbdc6-a013-d6c8-15a7-b2d2feb2455a@posteo.de> Received-SPF: pass client-ip=5.199.139.25; envelope-from=tomas@tuxteam.de; helo=mail.tuxteam.de X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: guile-user@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: General Guile related discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guile-user-bounces+guile-user=m.gmane-mx.org@gnu.org Original-Sender: "guile-user" Xref: news.gmane.io gmane.lisp.guile.user:17100 Archived-At: --kVXhAStRUZ/+rrGn Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Dec 20, 2020 at 06:57:34PM +0100, Zelphir Kaltstahl wrote: > Hello Tomas! >=20 > I think you are right about it only being down one stack frame down. The > checks are performed on what contains the next thing which is recurred on. Nice explanation :) > For a moment I thought "But isn't the null? check done twice in the > first cond part?" [...] This is one of the fantastic (and scary) things I often experience in this (scheme-y) context (take SICP, or the Little Schemer). Everything looks so easy, but whenever I try myself, I realise that I've been taken along a path along high mountains, with breathtaking views, and down there it gets messy and there are crocodiles. It takes a long time to massage one's messy, lowly programs into a form which approaches that deep beauty. But it's fun :) Cheers - t --kVXhAStRUZ/+rrGn Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAl/glbMACgkQBcgs9XrR2ka8/gCeKOk1Ez34Vhd3zhd8AaSqGiak HeMAn0MX9bJpo6b5Op2GjKCKU8RTb/Ik =gjBo -----END PGP SIGNATURE----- --kVXhAStRUZ/+rrGn--