Merge branch 'master' into comment-cache
[emacs.git] / lisp / gnus / nnoo.el
blob77e7f2a2d0e328888a34b66463b66ff7d301d59b
1 ;;; nnoo.el --- OO Gnus Backends
3 ;; Copyright (C) 1996-2017 Free Software Foundation, Inc.
5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
6 ;; Keywords: news
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software: you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation, either version 3 of the License, or
13 ;; (at your option) any later version.
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
23 ;;; Commentary:
25 ;;; Code:
27 (require 'nnheader)
28 (eval-when-compile (require 'cl))
30 (defvar nnoo-definition-alist nil)
31 (defvar nnoo-state-alist nil)
32 (defvar nnoo-parent-backend nil)
34 (defmacro defvoo (var init &optional doc &rest map)
35 "The same as `defvar', only takes list of variables to MAP to."
36 `(prog1
37 ,(if doc
38 `(defvar ,var ,init ,(concat doc "\n\nThis is a Gnus server variable. See Info node `(gnus)Select Methods'."))
39 `(defvar ,var ,init))
40 (nnoo-define ',var ',map)))
41 (put 'defvoo 'lisp-indent-function 2)
42 (put 'defvoo 'edebug-form-spec '(var init &optional doc &rest map))
44 (defmacro deffoo (func args &rest forms)
45 "The same as `defun', only register FUNC."
46 `(prog1
47 (defun ,func ,args ,@forms)
48 (nnoo-register-function ',func)))
49 (put 'deffoo 'lisp-indent-function 2)
50 (put 'deffoo 'edebug-form-spec '(&define name lambda-list def-body))
52 (defun nnoo-register-function (func)
53 (let ((funcs (nthcdr 3 (assoc (nnoo-backend func)
54 nnoo-definition-alist))))
55 (unless funcs
56 (error "%s belongs to a backend that hasn't been declared" func))
57 (setcar funcs (cons func (car funcs)))))
59 (defmacro nnoo-declare (backend &rest parents)
60 `(eval-and-compile
61 (if (assq ',backend nnoo-definition-alist)
62 (setcar (cdr (assq ',backend nnoo-definition-alist))
63 (mapcar 'list ',parents))
64 (push (list ',backend
65 (mapcar 'list ',parents)
66 nil nil)
67 nnoo-definition-alist))
68 (unless (assq ',backend nnoo-state-alist)
69 (push (list ',backend "*internal-non-initialized-backend*")
70 nnoo-state-alist))))
71 (put 'nnoo-declare 'lisp-indent-function 1)
73 (defun nnoo-parents (backend)
74 (nth 1 (assoc backend nnoo-definition-alist)))
76 (defun nnoo-variables (backend)
77 (nth 2 (assoc backend nnoo-definition-alist)))
79 (defun nnoo-functions (backend)
80 (nth 3 (assoc backend nnoo-definition-alist)))
82 (defmacro nnoo-import (backend &rest imports)
83 `(nnoo-import-1 ',backend ',imports))
84 (put 'nnoo-import 'lisp-indent-function 1)
86 (defun nnoo-import-1 (backend imports)
87 (let ((call-function
88 (if (symbolp (car imports)) (pop imports) 'nnoo-parent-function))
89 imp functions function)
90 (while (setq imp (pop imports))
91 (setq functions
92 (or (cdr imp)
93 (nnoo-functions (car imp))))
94 (while functions
95 (unless (fboundp
96 (setq function
97 (nnoo-symbol backend
98 (nnoo-rest-symbol (car functions)))))
99 (eval `(deffoo ,function (&rest args)
100 (,call-function ',backend ',(car functions) args))))
101 (pop functions)))))
103 (defun nnoo-parent-function (backend function args)
104 (let ((pbackend (nnoo-backend function))
105 (nnoo-parent-backend backend))
106 (nnoo-change-server pbackend
107 (nnoo-current-server backend)
108 (cdr (assq pbackend (nnoo-parents backend))))
109 (prog1
110 (apply function args)
111 ;; Copy the changed variables back into the child.
112 (let ((vars (cdr (assq pbackend (nnoo-parents backend)))))
113 (while vars
114 (set (cadar vars) (symbol-value (caar vars)))
115 (setq vars (cdr vars)))))))
117 (defun nnoo-execute (backend function &rest args)
118 "Execute FUNCTION on behalf of BACKEND."
119 (let ((pbackend (nnoo-backend function))
120 (nnoo-parent-backend backend))
121 (nnoo-change-server pbackend
122 (nnoo-current-server backend)
123 (cdr (assq pbackend (nnoo-parents backend))))
124 (prog1
125 (apply function args)
126 ;; Copy the changed variables back into the child.
127 (let ((vars (cdr (assq pbackend (nnoo-parents backend)))))
128 (while vars
129 (set (cadar vars) (symbol-value (caar vars)))
130 (setq vars (cdr vars)))))))
132 (defmacro nnoo-map-functions (backend &rest maps)
133 `(nnoo-map-functions-1 ',backend ',maps))
134 (put 'nnoo-map-functions 'lisp-indent-function 1)
136 (defun nnoo-map-functions-1 (backend maps)
137 (let (m margs i)
138 (while (setq m (pop maps))
139 (setq i 0
140 margs nil)
141 (while (< i (length (cdr m)))
142 (if (numberp (nth i (cdr m)))
143 (push `(nth ,i args) margs)
144 (push (nth i (cdr m)) margs))
145 (incf i))
146 (eval `(deffoo ,(nnoo-symbol backend (nnoo-rest-symbol (car m)))
147 (&rest args)
148 (nnoo-parent-function ',backend ',(car m)
149 ,(cons 'list (nreverse margs))))))))
151 (defun nnoo-backend (symbol)
152 (string-match "^[^-]+-" (symbol-name symbol))
153 (intern (substring (symbol-name symbol) 0 (1- (match-end 0)))))
155 (defun nnoo-rest-symbol (symbol)
156 (string-match "^[^-]+-" (symbol-name symbol))
157 (intern (substring (symbol-name symbol) (match-end 0))))
159 (defun nnoo-symbol (backend symbol)
160 (intern (format "%s-%s" backend symbol)))
162 (defun nnoo-define (var map)
163 (let* ((backend (nnoo-backend var))
164 (def (assq backend nnoo-definition-alist))
165 (parents (nth 1 def)))
166 (unless def
167 (error "%s belongs to a backend that hasn't been declared" var))
168 (setcar (nthcdr 2 def)
169 (delq (assq var (nth 2 def)) (nth 2 def)))
170 (setcar (nthcdr 2 def)
171 (cons (cons var (symbol-value var))
172 (nth 2 def)))
173 (while map
174 (nconc (assq (nnoo-backend (car map)) parents)
175 (list (list (pop map) var))))))
177 (defun nnoo-change-server (backend server defs)
178 (let* ((bstate (cdr (assq backend nnoo-state-alist)))
179 (current (car bstate))
180 (parents (nnoo-parents backend))
181 (server (if nnoo-parent-backend
182 (format "%s+%s" nnoo-parent-backend server)
183 server))
184 (bvariables (nnoo-variables backend))
185 state def)
186 ;; If we don't have a current state, we push an empty state
187 ;; onto the alist.
188 (unless bstate
189 (push (setq bstate (list backend nil))
190 nnoo-state-alist)
191 (pop bstate))
192 (if (equal server current)
194 (nnoo-push-server backend current)
195 (setq state (or (cdr (assoc server (cddr bstate)))
196 (nnoo-variables backend)))
197 (while state
198 (set (caar state) (cdar state))
199 (pop state))
200 (setcar bstate server)
201 (unless (cdr (assoc server (cddr bstate)))
202 (while (setq def (pop defs))
203 (unless (assq (car def) bvariables)
204 (nconc bvariables
205 (list (cons (car def) (and (boundp (car def))
206 (symbol-value (car def)))))))
207 (if (equal server "*internal-non-initialized-backend*")
208 (set (car def) (symbol-value (cadr def)))
209 (set (car def) (cadr def)))))
210 (while parents
211 (nnoo-change-server
212 (caar parents) (format "%s+%s" backend server)
213 (mapcar (lambda (def) (list (car def) (symbol-value (cadr def))))
214 (cdar parents)))
215 (pop parents))))
218 (defun nnoo-push-server (backend current)
219 (let ((bstate (assq backend nnoo-state-alist))
220 (defs (nnoo-variables backend)))
221 ;; Remove the old definition.
222 (setcdr (cdr bstate) (delq (assoc current (cddr bstate)) (cddr bstate)))
223 ;; If this is the first time we push the server (i. e., this is
224 ;; the nil server), then we update the default values of
225 ;; all the variables to reflect the current values.
226 (when (equal current "*internal-non-initialized-backend*")
227 (let ((defaults (nnoo-variables backend))
228 def)
229 (while (setq def (pop defaults))
230 (setcdr def (symbol-value (car def))))))
231 (let (state)
232 (while defs
233 (push (cons (caar defs) (symbol-value (caar defs)))
234 state)
235 (pop defs))
236 (nconc bstate (list (cons current state))))))
238 (defsubst nnoo-current-server-p (backend server)
239 (equal (nnoo-current-server backend)
240 (if nnoo-parent-backend
241 (format "%s+%s" nnoo-parent-backend server)
242 server)))
244 (defun nnoo-current-server (backend)
245 (nth 1 (assq backend nnoo-state-alist)))
247 (defun nnoo-close-server (backend &optional server)
248 (unless server
249 (setq server (nnoo-current-server backend)))
250 (when server
251 (let* ((bstate (cdr (assq backend nnoo-state-alist)))
252 (defs (assoc server (cdr bstate))))
253 (when bstate
254 (setcar bstate nil)
255 (setcdr bstate (delq defs (cdr bstate)))
256 (pop defs)
257 (while defs
258 (set (car (pop defs)) nil)))))
261 (defun nnoo-close (backend)
262 (setq nnoo-state-alist
263 (delq (assq backend nnoo-state-alist)
264 nnoo-state-alist))
267 (defun nnoo-status-message (backend server)
268 (nnheader-get-report backend))
270 (defun nnoo-server-opened (backend server)
271 (and (nnoo-current-server-p backend server)
272 nntp-server-buffer
273 (buffer-name nntp-server-buffer)))
275 (defmacro nnoo-define-basics (backend)
276 "Define `close-server', `server-opened' and `status-message'."
277 `(eval-and-compile
278 (nnoo-define-basics-1 ',backend)))
280 (defun nnoo-define-basics-1 (backend)
281 (let ((functions '(close-server server-opened status-message)))
282 (while functions
283 (eval `(deffoo ,(nnoo-symbol backend (car functions))
284 (&optional server)
285 (,(nnoo-symbol 'nnoo (pop functions)) ',backend server)))))
286 (eval `(deffoo ,(nnoo-symbol backend 'open-server)
287 (server &optional defs)
288 (nnoo-change-server ',backend server defs))))
290 (defmacro nnoo-define-skeleton (backend)
291 "Define all required backend functions for BACKEND.
292 All functions will return nil and report an error."
293 `(eval-and-compile
294 (nnoo-define-skeleton-1 ',backend)))
296 (defun nnoo-define-skeleton-1 (backend)
297 (let ((functions '(retrieve-headers
298 request-close request-article
299 request-group close-group
300 request-list request-post request-list-newsgroups))
301 function fun)
302 (while (setq function (pop functions))
303 (when (not (fboundp (setq fun (nnoo-symbol backend function))))
304 (eval `(deffoo ,fun
305 (&rest args)
306 (nnheader-report ',backend ,(format "%s-%s not implemented"
307 backend function))))))))
309 (defun nnoo-set (server &rest args)
310 (let ((parents (nnoo-parents (car server)))
311 (nnoo-parent-backend (car server)))
312 (while parents
313 (nnoo-change-server (caar parents)
314 (cadr server)
315 (cdar parents))
316 (pop parents)))
317 (nnoo-change-server (car server)
318 (cadr server) (cddr server))
319 (while args
320 (set (pop args) (pop args))))
322 (provide 'nnoo)
324 ;;; nnoo.el ends here