From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Ted Zlatanov Newsgroups: gmane.emacs.devel Subject: Re: ELisp futures and continuations/coroutines Date: Tue, 24 May 2011 21:02:38 -0500 Organization: =?utf-8?B?0KLQtdC+0LTQvtGAINCX0LvQsNGC0LDQvdC+0LI=?= @ Cienfuegos Message-ID: <8762ozbkqp.fsf@lifelogs.com> References: <87mxilezg8.fsf@lifelogs.com> <87boz0eov8.fsf@lifelogs.com> <87mxikrulm.fsf@lifelogs.com> <871uzw5asv.fsf@lifelogs.com> <878vu2ztua.fsf_-_@lifelogs.com> <87oc2ywwuy.fsf@ambire.localdomain> <87r57uyaeu.fsf@lifelogs.com> <87hb8qwsmo.fsf@ambire.localdomain> <87oc2yuu8u.fsf@lifelogs.com> <87d3jew4eq.fsf@ambire.localdomain> <8739k9s84c.fsf@lifelogs.com> <87tycmzxg3.fsf@ambire.localdomain> <87k4dh3363.fsf@lifelogs.com> <874o4l311n.fsf@lifelogs.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="=-=-=" X-Trace: dough.gmane.org 1306289583 1585 80.91.229.12 (25 May 2011 02:13:03 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 25 May 2011 02:13:03 +0000 (UTC) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed May 25 04:12:50 2011 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1QP3ab-0000Wb-WF for ged-emacs-devel@m.gmane.org; Wed, 25 May 2011 04:12:50 +0200 Original-Received: from localhost ([::1]:61000 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QP3ab-0003w8-GT for ged-emacs-devel@m.gmane.org; Tue, 24 May 2011 22:12:49 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:46512) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QP3R2-0002n8-DH for emacs-devel@gnu.org; Tue, 24 May 2011 22:02:57 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QP3R1-0000c3-EJ for emacs-devel@gnu.org; Tue, 24 May 2011 22:02:56 -0400 Original-Received: from lo.gmane.org ([80.91.229.12]:36438) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QP3R1-0000bv-5e for emacs-devel@gnu.org; Tue, 24 May 2011 22:02:55 -0400 Original-Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1QP3Qy-00058V-JD for emacs-devel@gnu.org; Wed, 25 May 2011 04:02:52 +0200 Original-Received: from c-67-186-102-106.hsd1.il.comcast.net ([67.186.102.106]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 25 May 2011 04:02:52 +0200 Original-Received: from tzz by c-67-186-102-106.hsd1.il.comcast.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 25 May 2011 04:02:52 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 159 Original-X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: c-67-186-102-106.hsd1.il.comcast.net X-Face: bd.DQ~'29fIs`T_%O%C\g%6jW)yi[zuz6; d4V0`@y-~$#3P_Ng{@m+e4o<4P'#(_GJQ%TT= D}[Ep*b!\e,fBZ'j_+#"Ps?s2!4H2-Y"sx" User-Agent: Gnus/5.110018 (No Gnus v0.18) Emacs/24.0.50 (gnu/linux) Cancel-Lock: sha1:K+gV8/cDia60K4thBPV2nt8p6Tw= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 80.91.229.12 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:139688 Archived-At: --=-=-= Content-Type: text/plain On Mon, 23 May 2011 12:45:51 -0300 Stefan Monnier wrote: >> The idea from the beginning was that this is a true data type, not an >> auxiliary library. At least deferred.el and fsm.el will use it, and I >> am in favor of adding deferred.el to Emacs as I mentioned. SM> I don't know of any package using deferred either, so it doesn't seem SM> urgent to add to Emacs's core. I'd rather keep such things on ELPA for SM> now until they prove their necessity. OK. >> I would rather not isolate its scope to just URL interactions because >> rewriting url-future-* to future-* later will be annoying SM> Maybe "annoying" but trivial to do. OK, I did as you asked. See attached, which has commentary, error handling, and ERT tests. I rewrote some trivial functions as defmacros. Thanks Ted --=-=-= Content-Type: application/emacs-lisp Content-Disposition: attachment; filename=url-future.el Content-Transfer-Encoding: quoted-printable ;;; url-future.el --- general futures facility for url.el ;; Copyright (C) 2011 Teodor Zlatanov ;; Author: Teodor Zlatanov ;; Keywords: data ;; This program is free software; you can redistribute it and/or modify ;; it under the terms of the GNU General Public License as published by ;; the Free Software Foundation, either version 3 of the License, or ;; (at your option) any later version. ;; This program is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; You should have received a copy of the GNU General Public License ;; along with this program. If not, see . ;;; Commentary: ;; Make a url-future (basically a defstruct): ;; (make-url-future :value (lambda () (calculation goes here)) ;; :callback (lambda (future) (use future on success)) ;; :errorback (lambda (future &rest error) (error handler))) ;; Then either call it with `url-future-call' or cancel it with ;; `url-future-cancel'. Generally the functions will return the ;; future itself, not the value it holds. Also the functions will ;; throw a url-future-already-done error if you try to call or cancel ;; a future more than once. ;; So, to get the value: ;; (when (url-future-completed-p future) (url-future-value future)) ;; See the ERT tests and the code for futher details. ;;; Code: (eval-when-compile (require 'cl)) (eval-when-compile (require 'ert)) (defstruct url-future callback errorback status value) (defmacro url-future-done-p (url-future) `(url-future-status ,url-future)) (defmacro url-future-completed-p (url-future) `(eq (url-future-status ,url-future) t)) (defmacro url-future-errored-p (url-future) `(eq (url-future-status ,url-future) 'error)) (defmacro url-future-cancelled-p (url-future) `(eq (url-future-status ,url-future) 'cancel)) (defun url-future-finish (url-future &optional status) (if (url-future-done-p url-future) (signal 'error 'url-future-already-done) (setf (url-future-status url-future) (or status t)) ;; the status must be such that the future was completed ;; to run the callback (when (url-future-completed-p url-future) (funcall (or (url-future-callback url-future) 'ignore) url-future)) url-future)) (defun url-future-errored (url-future errorcons) (if (url-future-done-p url-future) (signal 'error 'url-future-already-done) (setf (url-future-status url-future) 'error) (setf (url-future-value url-future) errorcons) (funcall (or (url-future-errorback url-future) 'ignore) url-future errorcons))) (defun url-future-call (url-future) (if (url-future-done-p url-future) (signal 'error 'url-future-already-done) (let ((ff (url-future-value url-future))) (when (functionp ff) (condition-case catcher (setf (url-future-value url-future) (funcall ff)) (error (url-future-errored url-future catcher))) (url-future-value url-future))) (if (url-future-errored-p url-future) url-future (url-future-finish url-future)))) (defun url-future-cancel (url-future) (if (url-future-done-p url-future) (signal 'error 'url-future-already-done) (url-future-finish url-future 'cancel))) (ert-deftest url-future-test () (let* ((text "running future") (good (make-url-future :value (lambda () (format text)) :callback (lambda (f) (set 'saver f)))) (bad (make-url-future :value (lambda () (/ 1 0)) :errorback (lambda (&rest d) (set 'saver d))= )) (tocancel (make-url-future :value (lambda () (/ 1 0)) :callback (lambda (f) (set 'saver f)) :errorback (lambda (&rest d) (set 'saver d)))) saver) (should (equal good (url-future-call good))) (should (equal good saver)) (should (equal text (url-future-value good))) (should (url-future-completed-p good)) (should-error (url-future-call good)) (setq saver nil) (should (equal bad (url-future-call bad))) (should-error (url-future-call bad)) (should (equal saver (list bad '(arith-error)))) (should (url-future-errored-p bad)) (setq saver nil) (should (equal (url-future-cancel tocancel) tocancel)) (should-error (url-future-call tocancel)) (should (null saver)) (should (url-future-cancelled-p tocancel)))) (provide 'url-future) ;;; url-future.el ends here --=-=-=--