1 ;;; nnoo.el --- OO Gnus Backends
3 ;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
4 ;; 2004, 2005 Free Software Foundation, Inc.
6 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software; you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation; either version 2, or (at your option)
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs; see the file COPYING. If not, write to the
23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24 ;; Boston, MA 02110-1301, USA.
30 (eval-when-compile (require 'cl))
33 (defvar nnoo-definition-alist nil)
34 (defvar nnoo-state-alist nil)
35 (defvar nnoo-parent-backend nil)
37 (defmacro defvoo (var init &optional doc &rest map)
38 "The same as `defvar', only takes list of variables to MAP to."
41 `(defvar ,var ,init ,(concat doc "\n\nThis is a Gnus server variable. See Info node `(gnus)Select Methods'."))
43 (nnoo-define ',var ',map)))
44 (put 'defvoo 'lisp-indent-function 2)
45 (put 'defvoo 'edebug-form-spec '(var init &optional doc &rest map))
47 (defmacro deffoo (func args &rest forms)
48 "The same as `defun', only register FUNC."
50 (defun ,func ,args ,@forms)
51 (nnoo-register-function ',func)))
52 (put 'deffoo 'lisp-indent-function 2)
53 (put 'deffoo 'edebug-form-spec '(&define name lambda-list def-body))
55 (defun nnoo-register-function (func)
56 (let ((funcs (nthcdr 3 (assoc (nnoo-backend func)
57 nnoo-definition-alist))))
59 (error "%s belongs to a backend that hasn't been declared" func))
60 (setcar funcs (cons func (car funcs)))))
62 (defmacro nnoo-declare (backend &rest parents)
65 (mapcar (lambda (p) (list p)) ',parents)
67 nnoo-definition-alist)
68 (push (list ',backend "*internal-non-initialized-backend*")
70 (put 'nnoo-declare 'lisp-indent-function 1)
72 (defun nnoo-parents (backend)
73 (nth 1 (assoc backend nnoo-definition-alist)))
75 (defun nnoo-variables (backend)
76 (nth 2 (assoc backend nnoo-definition-alist)))
78 (defun nnoo-functions (backend)
79 (nth 3 (assoc backend nnoo-definition-alist)))
81 (defmacro nnoo-import (backend &rest imports)
82 `(nnoo-import-1 ',backend ',imports))
83 (put 'nnoo-import 'lisp-indent-function 1)
85 (defun nnoo-import-1 (backend imports)
87 (if (symbolp (car imports)) (pop imports) 'nnoo-parent-function))
88 imp functions function)
89 (while (setq imp (pop imports))
92 (nnoo-functions (car imp))))
97 (nnoo-rest-symbol (car functions)))))
98 (eval `(deffoo ,function (&rest args)
99 (,call-function ',backend ',(car functions) args))))
102 (defun nnoo-parent-function (backend function args)
103 (let ((pbackend (nnoo-backend function))
104 (nnoo-parent-backend backend))
105 (nnoo-change-server pbackend
106 (nnoo-current-server backend)
107 (cdr (assq pbackend (nnoo-parents backend))))
109 (apply function args)
110 ;; Copy the changed variables back into the child.
111 (let ((vars (cdr (assq pbackend (nnoo-parents backend)))))
113 (set (cadar vars) (symbol-value (caar vars)))
114 (setq vars (cdr vars)))))))
116 (defun nnoo-execute (backend function &rest args)
117 "Execute FUNCTION on behalf of BACKEND."
118 (let ((pbackend (nnoo-backend function))
119 (nnoo-parent-backend backend))
120 (nnoo-change-server pbackend
121 (nnoo-current-server backend)
122 (cdr (assq pbackend (nnoo-parents backend))))
124 (apply function args)
125 ;; Copy the changed variables back into the child.
126 (let ((vars (cdr (assq pbackend (nnoo-parents backend)))))
128 (set (cadar vars) (symbol-value (caar vars)))
129 (setq vars (cdr vars)))))))
131 (defmacro nnoo-map-functions (backend &rest maps)
132 `(nnoo-map-functions-1 ',backend ',maps))
133 (put 'nnoo-map-functions 'lisp-indent-function 1)
135 (defun nnoo-map-functions-1 (backend maps)
137 (while (setq m (pop maps))
140 (while (< i (length (cdr m)))
141 (if (numberp (nth i (cdr m)))
142 (push `(nth ,i args) margs)
143 (push (nth i (cdr m)) margs))
145 (eval `(deffoo ,(nnoo-symbol backend (nnoo-rest-symbol (car m)))
147 (nnoo-parent-function ',backend ',(car m)
148 ,(cons 'list (nreverse margs))))))))
150 (defun nnoo-backend (symbol)
151 (string-match "^[^-]+-" (symbol-name symbol))
152 (intern (substring (symbol-name symbol) 0 (1- (match-end 0)))))
154 (defun nnoo-rest-symbol (symbol)
155 (string-match "^[^-]+-" (symbol-name symbol))
156 (intern (substring (symbol-name symbol) (match-end 0))))
158 (defun nnoo-symbol (backend symbol)
159 (intern (format "%s-%s" backend symbol)))
161 (defun nnoo-define (var map)
162 (let* ((backend (nnoo-backend var))
163 (def (assq backend nnoo-definition-alist))
164 (parents (nth 1 def)))
166 (error "%s belongs to a backend that hasn't been declared" var))
167 (setcar (nthcdr 2 def)
168 (delq (assq var (nth 2 def)) (nth 2 def)))
169 (setcar (nthcdr 2 def)
170 (cons (cons var (symbol-value var))
173 (nconc (assq (nnoo-backend (car map)) parents)
174 (list (list (pop map) var))))))
176 (defun nnoo-change-server (backend server defs)
177 (let* ((bstate (cdr (assq backend nnoo-state-alist)))
178 (current (car bstate))
179 (parents (nnoo-parents backend))
180 (server (if nnoo-parent-backend
181 (format "%s+%s" nnoo-parent-backend server)
183 (bvariables (nnoo-variables backend))
185 ;; If we don't have a current state, we push an empty state
188 (push (setq bstate (list backend nil))
191 (if (equal server current)
193 (nnoo-push-server backend current)
194 (setq state (or (cdr (assoc server (cddr bstate)))
195 (nnoo-variables backend)))
197 (set (caar state) (cdar state))
199 (setcar bstate server)
200 (unless (cdr (assoc server (cddr bstate)))
201 (while (setq def (pop defs))
202 (unless (assq (car def) bvariables)
204 (list (cons (car def) (and (boundp (car def))
205 (symbol-value (car def)))))))
206 (if (equal server "*internal-non-initialized-backend*")
207 (set (car def) (symbol-value (cadr def)))
208 (set (car def) (cadr def)))))
211 (caar parents) (format "%s+%s" backend server)
212 (mapcar (lambda (def) (list (car def) (symbol-value (cadr def))))
217 (defun nnoo-push-server (backend current)
218 (let ((bstate (assq backend nnoo-state-alist))
219 (defs (nnoo-variables backend)))
220 ;; Remove the old definition.
221 (setcdr (cdr bstate) (delq (assoc current (cddr bstate)) (cddr bstate)))
222 ;; If this is the first time we push the server (i. e., this is
223 ;; the nil server), then we update the default values of
224 ;; all the variables to reflect the current values.
225 (when (equal current "*internal-non-initialized-backend*")
226 (let ((defaults (nnoo-variables backend))
228 (while (setq def (pop defaults))
229 (setcdr def (symbol-value (car def))))))
232 (push (cons (caar defs) (symbol-value (caar defs)))
235 (nconc bstate (list (cons current state))))))
237 (defsubst nnoo-current-server-p (backend server)
238 (equal (nnoo-current-server backend)
239 (if nnoo-parent-backend
240 (format "%s+%s" nnoo-parent-backend server)
243 (defun nnoo-current-server (backend)
244 (nth 1 (assq backend nnoo-state-alist)))
246 (defun nnoo-close-server (backend &optional server)
248 (setq server (nnoo-current-server backend)))
250 (let* ((bstate (cdr (assq backend nnoo-state-alist)))
251 (defs (assoc server (cdr bstate))))
254 (setcdr bstate (delq defs (cdr bstate)))
257 (set (car (pop defs)) nil)))))
260 (defun nnoo-close (backend)
261 (setq nnoo-state-alist
262 (delq (assq backend nnoo-state-alist)
266 (defun nnoo-status-message (backend server)
267 (nnheader-get-report backend))
269 (defun nnoo-server-opened (backend server)
270 (and (nnoo-current-server-p backend server)
272 (buffer-name nntp-server-buffer)))
274 (defmacro nnoo-define-basics (backend)
275 "Define `close-server', `server-opened' and `status-message'."
277 (nnoo-define-basics-1 ',backend)))
279 (defun nnoo-define-basics-1 (backend)
280 (let ((functions '(close-server server-opened status-message)))
282 (eval `(deffoo ,(nnoo-symbol backend (car functions))
284 (,(nnoo-symbol 'nnoo (pop functions)) ',backend server)))))
285 (eval `(deffoo ,(nnoo-symbol backend 'open-server)
286 (server &optional defs)
287 (nnoo-change-server ',backend server defs))))
289 (defmacro nnoo-define-skeleton (backend)
290 "Define all required backend functions for BACKEND.
291 All functions will return nil and report an error."
293 (nnoo-define-skeleton-1 ',backend)))
295 (defun nnoo-define-skeleton-1 (backend)
296 (let ((functions '(retrieve-headers
297 request-close request-article
298 request-group close-group
299 request-list request-post request-list-newsgroups))
301 (while (setq function (pop functions))
302 (when (not (fboundp (setq fun (nnoo-symbol backend function))))
305 (nnheader-report ',backend ,(format "%s-%s not implemented"
306 backend function))))))))
308 (defun nnoo-set (server &rest args)
309 (let ((parents (nnoo-parents (car server)))
310 (nnoo-parent-backend (car server)))
312 (nnoo-change-server (caar parents)
316 (nnoo-change-server (car server)
317 (cadr server) (cddr server))
319 (set (pop args) (pop args))))
323 ;;; nnoo.el ends here