From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Zelphir Kaltstahl Newsgroups: gmane.lisp.guile.user Subject: Re: Surprising behavior of eq? Date: Sun, 20 Sep 2020 15:09:30 +0200 Message-ID: References: <8e1d9874-4659-cca5-03da-c2c0df102c56@posteo.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="19336"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Icedove/68.10.0 To: guile-user@gnu.org Original-X-From: guile-user-bounces+guile-user=m.gmane-mx.org@gnu.org Sun Sep 20 15:11:18 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 1kJz7e-0004xA-CL for guile-user@m.gmane-mx.org; Sun, 20 Sep 2020 15:11:18 +0200 Original-Received: from localhost ([::1]:38042 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kJz7d-0001Qb-3E for guile-user@m.gmane-mx.org; Sun, 20 Sep 2020 09:11:17 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:60466) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kJz61-0000KB-Em for guile-user@gnu.org; Sun, 20 Sep 2020 09:09:37 -0400 Original-Received: from mout01.posteo.de ([185.67.36.65]:55257) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kJz5y-0001Hb-K0 for guile-user@gnu.org; Sun, 20 Sep 2020 09:09:37 -0400 Original-Received: from submission (posteo.de [89.146.220.130]) by mout01.posteo.de (Postfix) with ESMTPS id AC2D216005F for ; Sun, 20 Sep 2020 15:09:31 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.de; s=2017; t=1600607371; bh=oVWQAUPJYUIFvFogK2KIIN1PuBY9JJgumZqGU3jWabA=; h=Subject:To:From:Date:From; b=OFrANQXzTfikSBTL0D3l0sfE7MggObJ74CbRbR8Udf2h1gaOGSp285FlPv0N767b4 v9DSEZLO6HyldV67A8j+nvTMC5DUQn2hO5T5DLSHs9SzpCEG/Gki+dPvRl01XqbVZN p3LgeO8I+ATJ96T+yf85cjsx07pORmr9Un2GBC8/l0HT4DeCYyNGeLILyxJZ18gB4H +o2J7BGFkmYysNifslx8wAEuo32cAqADlncrvT3AgIiMlZwbDrEqf/lo92Em4LmDpM uLjMqNXqe36JR/bmW8d9HTsqAd4XywqDoelCXOlQ2ybCQU9JZfdBN30LQd9UpW8mgM r3kvKUbHtyV4A== Original-Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4BvSZy5rRjz6tm5 for ; Sun, 20 Sep 2020 15:09:30 +0200 (CEST) In-Reply-To: <8e1d9874-4659-cca5-03da-c2c0df102c56@posteo.de> Content-Language: en-US Received-SPF: pass client-ip=185.67.36.65; envelope-from=zelphirkaltstahl@posteo.de; helo=mout01.posteo.de X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/20 09:09:32 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] 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, HTML_MESSAGE=0.001, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-Content-Filtered-By: Mailman/MimeDel 2.1.23 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:16933 Archived-At: And I've noticed something more about equality stuff in the context of tests: ~~~~ (eqv? "a" "a") $3 = #t ;; but (define char->string (λ (c) (list->string (list c)))) (import ;; unit tests (srfi srfi-64)) (test-begin "string-utils-test") (test-group "char-to-string-test" (test-eqv "char->string converts a character to a string" "a" (char->string #\a))) (test-end "string-utils-test") %%%% Starting test string-utils-test (Writing full log to "string-utils-test.log") $2 = ("string-utils-test") :19: FAIL char->string converts a character to a string # of unexpected failures 1 ~~~~ So while (eqv? ...) gives the correct (?) result, the test procedure (test-eqv ...) which seems to indicate using (eqv? ...) via its name does not think of the two strings as equivalent. On 20.09.20 14:19, Zelphir Kaltstahl wrote: > Sorry, I misclicked "send" when I wanted to further edit my e-mail ... > > My Guile version is: > > ~~~~ > (version) > $6 = "3.0.4" > ~~~~ > > On 20.09.20 14:16, Zelphir Kaltstahl wrote: >> Hello Guile users, >> >> I just noticed something weird about eq?. >> >> My Guile version is: >> >> >> I get the different results, depending on whether I define some >> bindings in a let or using define: >> >> (In Emacs Geiser:) >> >> ~~~~ >> (define x '(10 9)) >> (define y '(10 9)) >> (eq? x y) >> $2 = #f >> >> (let ([x '(10 9)] >> [y '(10 9)]) >> (eq? x y)) >> $3 = #t >> ~~~~ >> >> Is this intentional or a bug? >> >> I first noticed something strange when writing the following code: >> >> ~~~~DEFINITION~~~~ >> (define make-multiple-list-remover >> (λ (equal-proc) >> (λ (lst unwanted) >> (let loop ([remaining-list lst]) >> (cond >> [(null? remaining-list) >> '()] >> [(equal-proc (car remaining-list) unwanted) >> (loop (cdr remaining-list))] >> [else >> (cons (car remaining-list) >> (loop (cdr remaining-list)))]))))) >> ~~~~ >> >> ~~~~TEST~~~~ >> (let ([a '(9 10)] >> [b '(9 10)]) >> (test-equal "make-multiple-list-remover-03" >> `(1 2 (3) (4) ,a) >> ((make-multiple-list-remover eq?) >> `(a b (c) (d) ,a) b))) >> ~~~~ >> >> I was wondering, why the test fails. I think (eq? ...) should not be >> able to see the equivalence of both lists a and b, just like when >> defined using (define ...). >> >> I can also run it in the REPL and see the difference: >> >> ~~~~ >> (define a '(9 10)) >> (define b '(9 10)) >> ((make-multiple-list-remover eq?) >> `(a b (c) (d) ,a) b) >> $4 = (a b (c) (d) (9 10)) >> >> (let ([a '(9 10)] >> [b '(9 10)]) >> ((make-multiple-list-remover eq?) >> `(a b (c) (d) ,a) b)) >> $5 = (a b (c) (d)) >> ~~~~ >> >> Somehow the bindings of let seem to be different from the bindings >> created using define. What about using define inside let? >> >> ~~~~ >> >> ~~~~ >> -- >> repositories: https://notabug.org/ZelphirKaltstahl > Somehow the bindings of let seem to be different from the bindings > created using define. What about using define inside let? > > ~~~~ > (let ([unrelated 'bla]) > (define a '(9 10)) > (define b '(9 10)) > ((make-multiple-list-remover eq?) > `(a b (c) (d) ,a) b)) > $7 = (a b (c) (d)) > ~~~~ > > So there the define usage also differs from when I use define on the top > level. Perhaps that is the difference? On which level the bindings are > defined? > > Regards, > Zelphir > -- repositories: https://notabug.org/ZelphirKaltstahl