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eec82323 | 1 | ;;; nnoo.el --- OO Gnus Backends |
6748645f | 2 | ;; Copyright (C) 1996,97,98 Free Software Foundation, Inc. |
eec82323 | 3 | |
6748645f | 4 | ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org> |
eec82323 LMI |
5 | ;; Keywords: news |
6 | ||
7 | ;; This file is part of GNU Emacs. | |
8 | ||
9 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
10 | ;; it under the terms of the GNU General Public License as published by | |
11 | ;; the Free Software Foundation; either version 2, or (at your option) | |
12 | ;; any later version. | |
13 | ||
14 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
15 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | ;; GNU General Public License for more details. | |
18 | ||
19 | ;; You should have received a copy of the GNU General Public License | |
20 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
21 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | ;; Boston, MA 02111-1307, USA. | |
23 | ||
24 | ;;; Commentary: | |
25 | ||
26 | ;;; Code: | |
27 | ||
28 | (require 'nnheader) | |
349f4e97 | 29 | (eval-when-compile (require 'cl)) |
eec82323 LMI |
30 | |
31 | (defvar nnoo-definition-alist nil) | |
32 | (defvar nnoo-state-alist nil) | |
6748645f | 33 | (defvar nnoo-parent-backend nil) |
eec82323 LMI |
34 | |
35 | (defmacro defvoo (var init &optional doc &rest map) | |
36 | "The same as `defvar', only takes list of variables to MAP to." | |
37 | `(prog1 | |
38 | ,(if doc | |
39 | `(defvar ,var ,init ,doc) | |
40 | `(defvar ,var ,init)) | |
41 | (nnoo-define ',var ',map))) | |
42 | (put 'defvoo 'lisp-indent-function 2) | |
43 | (put 'defvoo 'edebug-form-spec '(var init &optional doc &rest map)) | |
44 | ||
45 | (defmacro deffoo (func args &rest forms) | |
46 | "The same as `defun', only register FUNC." | |
47 | `(prog1 | |
48 | (defun ,func ,args ,@forms) | |
49 | (nnoo-register-function ',func))) | |
50 | (put 'deffoo 'lisp-indent-function 2) | |
51 | (put 'deffoo 'edebug-form-spec '(&define name lambda-list def-body)) | |
52 | ||
53 | (defun nnoo-register-function (func) | |
54 | (let ((funcs (nthcdr 3 (assoc (nnoo-backend func) | |
55 | nnoo-definition-alist)))) | |
56 | (unless funcs | |
57 | (error "%s belongs to a backend that hasn't been declared" func)) | |
58 | (setcar funcs (cons func (car funcs))))) | |
59 | ||
60 | (defmacro nnoo-declare (backend &rest parents) | |
61 | `(eval-and-compile | |
62 | (push (list ',backend | |
63 | (mapcar (lambda (p) (list p)) ',parents) | |
64 | nil nil) | |
65 | nnoo-definition-alist) | |
66 | (push (list ',backend "*internal-non-initialized-backend*") | |
67 | nnoo-state-alist))) | |
68 | (put 'nnoo-declare 'lisp-indent-function 1) | |
69 | ||
70 | (defun nnoo-parents (backend) | |
71 | (nth 1 (assoc backend nnoo-definition-alist))) | |
72 | ||
73 | (defun nnoo-variables (backend) | |
74 | (nth 2 (assoc backend nnoo-definition-alist))) | |
75 | ||
76 | (defun nnoo-functions (backend) | |
77 | (nth 3 (assoc backend nnoo-definition-alist))) | |
78 | ||
79 | (defmacro nnoo-import (backend &rest imports) | |
80 | `(nnoo-import-1 ',backend ',imports)) | |
81 | (put 'nnoo-import 'lisp-indent-function 1) | |
82 | ||
83 | (defun nnoo-import-1 (backend imports) | |
84 | (let ((call-function | |
85 | (if (symbolp (car imports)) (pop imports) 'nnoo-parent-function)) | |
86 | imp functions function) | |
87 | (while (setq imp (pop imports)) | |
88 | (setq functions | |
89 | (or (cdr imp) | |
90 | (nnoo-functions (car imp)))) | |
91 | (while functions | |
6748645f LMI |
92 | (unless (fboundp |
93 | (setq function | |
94 | (nnoo-symbol backend | |
95 | (nnoo-rest-symbol (car functions))))) | |
eec82323 LMI |
96 | (eval `(deffoo ,function (&rest args) |
97 | (,call-function ',backend ',(car functions) args)))) | |
98 | (pop functions))))) | |
99 | ||
100 | (defun nnoo-parent-function (backend function args) | |
6748645f LMI |
101 | (let ((pbackend (nnoo-backend function)) |
102 | (nnoo-parent-backend backend)) | |
103 | (nnoo-change-server pbackend | |
104 | (nnoo-current-server backend) | |
eec82323 | 105 | (cdr (assq pbackend (nnoo-parents backend)))) |
6748645f LMI |
106 | (prog1 |
107 | (apply function args) | |
108 | ;; Copy the changed variables back into the child. | |
109 | (let ((vars (cdr (assq pbackend (nnoo-parents backend))))) | |
110 | (while vars | |
111 | (set (cadar vars) (symbol-value (caar vars))) | |
112 | (setq vars (cdr vars))))))) | |
eec82323 LMI |
113 | |
114 | (defun nnoo-execute (backend function &rest args) | |
115 | "Execute FUNCTION on behalf of BACKEND." | |
6748645f LMI |
116 | (let ((pbackend (nnoo-backend function)) |
117 | (nnoo-parent-backend backend)) | |
118 | (nnoo-change-server pbackend | |
119 | (nnoo-current-server backend) | |
eec82323 | 120 | (cdr (assq pbackend (nnoo-parents backend)))) |
6748645f LMI |
121 | (prog1 |
122 | (apply function args) | |
123 | ;; Copy the changed variables back into the child. | |
124 | (let ((vars (cdr (assq pbackend (nnoo-parents backend))))) | |
125 | (while vars | |
126 | (set (cadar vars) (symbol-value (caar vars))) | |
127 | (setq vars (cdr vars))))))) | |
eec82323 LMI |
128 | |
129 | (defmacro nnoo-map-functions (backend &rest maps) | |
130 | `(nnoo-map-functions-1 ',backend ',maps)) | |
131 | (put 'nnoo-map-functions 'lisp-indent-function 1) | |
132 | ||
133 | (defun nnoo-map-functions-1 (backend maps) | |
134 | (let (m margs i) | |
135 | (while (setq m (pop maps)) | |
136 | (setq i 0 | |
137 | margs nil) | |
138 | (while (< i (length (cdr m))) | |
139 | (if (numberp (nth i (cdr m))) | |
140 | (push `(nth ,i args) margs) | |
141 | (push (nth i (cdr m)) margs)) | |
142 | (incf i)) | |
143 | (eval `(deffoo ,(nnoo-symbol backend (nnoo-rest-symbol (car m))) | |
144 | (&rest args) | |
145 | (nnoo-parent-function ',backend ',(car m) | |
146 | ,(cons 'list (nreverse margs)))))))) | |
147 | ||
148 | (defun nnoo-backend (symbol) | |
149 | (string-match "^[^-]+-" (symbol-name symbol)) | |
150 | (intern (substring (symbol-name symbol) 0 (1- (match-end 0))))) | |
151 | ||
152 | (defun nnoo-rest-symbol (symbol) | |
153 | (string-match "^[^-]+-" (symbol-name symbol)) | |
154 | (intern (substring (symbol-name symbol) (match-end 0)))) | |
155 | ||
156 | (defun nnoo-symbol (backend symbol) | |
157 | (intern (format "%s-%s" backend symbol))) | |
158 | ||
159 | (defun nnoo-define (var map) | |
160 | (let* ((backend (nnoo-backend var)) | |
161 | (def (assq backend nnoo-definition-alist)) | |
162 | (parents (nth 1 def))) | |
163 | (unless def | |
a8151ef7 | 164 | (error "%s belongs to a backend that hasn't been declared" var)) |
eec82323 LMI |
165 | (setcar (nthcdr 2 def) |
166 | (delq (assq var (nth 2 def)) (nth 2 def))) | |
167 | (setcar (nthcdr 2 def) | |
168 | (cons (cons var (symbol-value var)) | |
169 | (nth 2 def))) | |
170 | (while map | |
171 | (nconc (assq (nnoo-backend (car map)) parents) | |
172 | (list (list (pop map) var)))))) | |
173 | ||
174 | (defun nnoo-change-server (backend server defs) | |
175 | (let* ((bstate (cdr (assq backend nnoo-state-alist))) | |
176 | (current (car bstate)) | |
177 | (parents (nnoo-parents backend)) | |
6748645f LMI |
178 | (server (if nnoo-parent-backend |
179 | (format "%s+%s" nnoo-parent-backend server) | |
180 | server)) | |
eec82323 LMI |
181 | (bvariables (nnoo-variables backend)) |
182 | state def) | |
6748645f LMI |
183 | ;; If we don't have a current state, we push an empty state |
184 | ;; onto the alist. | |
eec82323 LMI |
185 | (unless bstate |
186 | (push (setq bstate (list backend nil)) | |
187 | nnoo-state-alist) | |
188 | (pop bstate)) | |
189 | (if (equal server current) | |
190 | t | |
191 | (nnoo-push-server backend current) | |
192 | (setq state (or (cdr (assoc server (cddr bstate))) | |
193 | (nnoo-variables backend))) | |
194 | (while state | |
195 | (set (caar state) (cdar state)) | |
196 | (pop state)) | |
197 | (setcar bstate server) | |
198 | (unless (cdr (assoc server (cddr bstate))) | |
199 | (while (setq def (pop defs)) | |
200 | (unless (assq (car def) bvariables) | |
201 | (nconc bvariables | |
202 | (list (cons (car def) (and (boundp (car def)) | |
203 | (symbol-value (car def))))))) | |
6748645f LMI |
204 | (if (equal server "*internal-non-initialized-backend*") |
205 | (set (car def) (symbol-value (cadr def))) | |
206 | (set (car def) (cadr def))))) | |
eec82323 LMI |
207 | (while parents |
208 | (nnoo-change-server | |
6748645f | 209 | (caar parents) (format "%s+%s" backend server) |
eec82323 LMI |
210 | (mapcar (lambda (def) (list (car def) (symbol-value (cadr def)))) |
211 | (cdar parents))) | |
212 | (pop parents)))) | |
213 | t) | |
214 | ||
215 | (defun nnoo-push-server (backend current) | |
216 | (let ((bstate (assq backend nnoo-state-alist)) | |
217 | (defs (nnoo-variables backend))) | |
218 | ;; Remove the old definition. | |
219 | (setcdr (cdr bstate) (delq (assoc current (cddr bstate)) (cddr bstate))) | |
220 | ;; If this is the first time we push the server (i. e., this is | |
221 | ;; the nil server), then we update the default values of | |
222 | ;; all the variables to reflect the current values. | |
223 | (when (equal current "*internal-non-initialized-backend*") | |
224 | (let ((defaults (nnoo-variables backend)) | |
225 | def) | |
226 | (while (setq def (pop defaults)) | |
227 | (setcdr def (symbol-value (car def)))))) | |
228 | (let (state) | |
229 | (while defs | |
230 | (push (cons (caar defs) (symbol-value (caar defs))) | |
231 | state) | |
232 | (pop defs)) | |
233 | (nconc bstate (list (cons current state)))))) | |
234 | ||
235 | (defsubst nnoo-current-server-p (backend server) | |
6748645f LMI |
236 | (equal (nnoo-current-server backend) |
237 | (if nnoo-parent-backend | |
238 | (format "%s+%s" nnoo-parent-backend server) | |
239 | server))) | |
eec82323 LMI |
240 | |
241 | (defun nnoo-current-server (backend) | |
242 | (nth 1 (assq backend nnoo-state-alist))) | |
243 | ||
244 | (defun nnoo-close-server (backend &optional server) | |
245 | (unless server | |
246 | (setq server (nnoo-current-server backend))) | |
247 | (when server | |
248 | (let* ((bstate (cdr (assq backend nnoo-state-alist))) | |
249 | (defs (assoc server (cdr bstate)))) | |
250 | (when bstate | |
251 | (setcar bstate nil) | |
252 | (setcdr bstate (delq defs (cdr bstate))) | |
253 | (pop defs) | |
254 | (while defs | |
255 | (set (car (pop defs)) nil))))) | |
256 | t) | |
257 | ||
258 | (defun nnoo-close (backend) | |
259 | (setq nnoo-state-alist | |
260 | (delq (assq backend nnoo-state-alist) | |
261 | nnoo-state-alist)) | |
262 | t) | |
263 | ||
264 | (defun nnoo-status-message (backend server) | |
265 | (nnheader-get-report backend)) | |
266 | ||
267 | (defun nnoo-server-opened (backend server) | |
268 | (and (nnoo-current-server-p backend server) | |
269 | nntp-server-buffer | |
270 | (buffer-name nntp-server-buffer))) | |
271 | ||
272 | (defmacro nnoo-define-basics (backend) | |
273 | "Define `close-server', `server-opened' and `status-message'." | |
274 | `(eval-and-compile | |
275 | (nnoo-define-basics-1 ',backend))) | |
276 | ||
277 | (defun nnoo-define-basics-1 (backend) | |
278 | (let ((functions '(close-server server-opened status-message))) | |
279 | (while functions | |
280 | (eval `(deffoo ,(nnoo-symbol backend (car functions)) | |
281 | (&optional server) | |
282 | (,(nnoo-symbol 'nnoo (pop functions)) ',backend server))))) | |
283 | (eval `(deffoo ,(nnoo-symbol backend 'open-server) | |
284 | (server &optional defs) | |
285 | (nnoo-change-server ',backend server defs)))) | |
286 | ||
287 | (defmacro nnoo-define-skeleton (backend) | |
288 | "Define all required backend functions for BACKEND. | |
289 | All functions will return nil and report an error." | |
290 | `(eval-and-compile | |
291 | (nnoo-define-skeleton-1 ',backend))) | |
292 | ||
293 | (defun nnoo-define-skeleton-1 (backend) | |
294 | (let ((functions '(retrieve-headers | |
295 | request-close request-article | |
296 | request-group close-group | |
297 | request-list request-post request-list-newsgroups)) | |
298 | function fun) | |
299 | (while (setq function (pop functions)) | |
300 | (when (not (fboundp (setq fun (nnoo-symbol backend function)))) | |
301 | (eval `(deffoo ,fun | |
302 | (&rest args) | |
303 | (nnheader-report ',backend ,(format "%s-%s not implemented" | |
304 | backend function)))))))) | |
305 | (provide 'nnoo) | |
306 | ||
307 | ;;; nnoo.el ends here. |