1 ;;; eieio-compat.el --- Compatibility with Older EIEIO versions -*- lexical-binding:t -*-
3 ;; Copyright (C) 1995-1996, 1998-2015 Free Software Foundation, Inc.
5 ;; Author: Eric M. Ludlam <zappo@gnu.org>
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/>.
25 ;; Backward compatibility definition of old EIEIO functions in
26 ;; terms of newer equivalent.
28 ;; The main elements are the old EIEIO `defmethod' and `defgeneric' which are
29 ;; now implemented on top of cl-generic. The differences we have to
31 ;; - EIEIO's :static methods (turned into a new `eieio--static' specializer).
32 ;; - EIEIO's support for `call-next-method' and `next-method-p' instead of
33 ;; `cl-next-method-p' and `cl-call-next-method' (simple matter of renaming).
34 ;; - Different errors are signaled.
35 ;; - EIEIO's defgeneric does not reset the function.
36 ;; - EIEIO's no-next-method and no-applicable-method can't be aliases of
37 ;; cl-generic's namesakes since they have different calling conventions,
38 ;; which means that packages that (defmethod no-next-method ..) don't work.
39 ;; - EIEIO's `call-next-method' and `next-method-p' had dynamic scope whereas
40 ;; cl-generic's `cl-next-method-p' and `cl-call-next-method' are lexically
48 (put 'eieio--defalias 'byte-hunk-handler
49 #'byte-compile-file-form-defalias) ;;(get 'defalias 'byte-hunk-handler)
51 (defun eieio--defalias (name body)
52 "Like `defalias', but with less side-effects.
53 More specifically, it has no side-effects at all when the new function
54 definition is the same (`eq') as the old one."
55 (cl-assert (not (symbolp body)))
56 (while (and (fboundp name) (symbolp (symbol-function name)))
57 ;; Follow aliases, so methods applied to obsolete aliases still work.
58 (setq name (symbol-function name)))
59 (unless (and (fboundp name)
60 (eq (symbol-function name) body))
61 (defalias name body)))
64 (defmacro defgeneric (method args &optional doc-string)
65 "Create a generic function METHOD.
66 DOC-STRING is the base documentation for this class. A generic
67 function has no body, as its purpose is to decide which method body
68 is appropriate to use. Uses `defmethod' to create methods, and calls
69 `defgeneric' for you. With this implementation the ARGS are
70 currently ignored. You can use `defgeneric' to apply specialized
71 top level documentation to a method."
72 (declare (doc-string 3) (obsolete cl-defgeneric "25.1"))
73 `(eieio--defalias ',method
74 (eieio--defgeneric-init-form
76 ,(if doc-string (help-add-fundoc-usage doc-string args)))))
79 (defmacro defmethod (method &rest args)
80 "Create a new METHOD through `defgeneric' with ARGS.
82 The optional second argument KEY is a specifier that
83 modifies how the method is called, including:
84 :before - Method will be called before the :primary
85 :primary - The default if not specified
86 :after - Method will be called after the :primary
87 :static - First arg could be an object or class
88 The next argument is the ARGLIST. The ARGLIST specifies the arguments
89 to the method as with `defun'. The first argument can have a type
91 ((VARNAME CLASS) ARG2 ...)
92 where VARNAME is the name of the local variable for the method being
93 created. The CLASS is a class symbol for a class made with `defclass'.
94 A DOCSTRING comes after the ARGLIST, and is optional.
95 All the rest of the args are the BODY of the method. A method will
96 return the value of the last form in the BODY.
100 (defmethod mymethod [:before | :primary | :after | :static]
101 ((typearg class-name) arg2 &optional opt &rest rest)
104 (declare (doc-string 3) (obsolete cl-defmethod "25.1")
106 (&define ; this means we are defining something
107 [&or name ("setf" :name setf name)]
108 ;; ^^ This is the methods symbol
109 [ &optional symbolp ] ; this is key :before etc
111 [ &optional stringp ] ; documentation string
112 def-body ; part to be debugged
114 (let* ((key (if (keywordp (car args)) (pop args)))
117 (fargs (if (consp arg1)
118 (cons (car arg1) (cdr params))
120 (class (if (consp arg1) (nth 1 arg1)))
121 (code `(lambda ,fargs ,@(cdr args))))
123 ;; Make sure there is a generic and the byte-compiler sees it.
124 (defgeneric ,method ,args)
125 (eieio--defmethod ',method ',key ',class #',code))))
127 (add-function :before-until cl-generic-tagcode-function
128 #'eieio--generic-static-tagcode)
129 (defun eieio--generic-static-tagcode (type name)
130 (and (eq 'eieio--static (car-safe type))
132 ((symbolp ,name) (eieio--class-v ,name))
133 ((vectorp ,name) (aref ,name 0))))))
135 (add-function :around cl-generic-tag-types-function
136 #'eieio--generic-static-tag-types)
137 (defun eieio--generic-static-tag-types (orig-fun tag)
139 ((or (eieio--class-p tag)
140 (and (symbolp tag) (boundp tag) (eieio--class-p (symbol-value tag))))
141 (let ((superclasses (funcall orig-fun tag))
143 ;; Interleave: (subclass <foo>) (eieio--static <foo>) <subclass <bar>) ..
144 (dolist (superclass superclasses)
145 (push superclass types)
146 (push `(eieio--static
147 ,(if (consp superclass) (cadr superclass) superclass))
150 (t (funcall orig-fun tag))))
153 (defun eieio--defgeneric-init-form (method doc-string)
154 (if doc-string (put method 'function-documentation doc-string))
155 (if (memq method '(no-next-method no-applicable-method))
156 (symbol-function method)
157 (let ((generic (cl-generic-ensure-function method)))
158 (symbol-function (cl--generic-name generic)))))
161 (defun eieio--defmethod (method kind argclass code)
162 (setq kind (intern (downcase (symbol-name kind))))
163 (let* ((specializer (if (not (eq kind :static))
166 `(eieio--static ,argclass)))
167 (uses-cnm (not (memq kind '(:before :after))))
168 (specializers `((arg ,specializer)))
170 ;; Backward compatibility for `no-next-method' and
171 ;; `no-applicable-method', which have slightly different calling
172 ;; convention than their cl-generic counterpart.
175 (setq method 'cl-no-next-method)
176 (setq specializers `(generic method ,@specializers))
177 (lambda (_generic _method &rest args) (apply code args)))
178 (`no-applicable-method
179 (setq method 'cl-no-applicable-method)
180 (setq specializers `(generic ,@specializers))
181 (lambda (generic arg &rest args) (apply code arg generic args)))
183 (cl-generic-define-method
184 method (unless (memq kind '(nil :primary)) (list kind))
185 specializers uses-cnm
187 (let* ((docstring (documentation code 'raw))
188 (args (help-function-arglist code 'preserve-names))
189 (doc-only (if docstring
190 (let ((split (help-split-fundoc docstring nil)))
191 (if split (cdr split) docstring))))
192 (new-docstring (help-add-fundoc-usage doc-only
193 (cons 'cl-cnm args))))
194 ;; FIXME: ¡Add new-docstring to those closures!
195 (lambda (cnm &rest args)
196 (cl-letf (((symbol-function 'call-next-method) cnm)
197 ((symbol-function 'next-method-p)
198 (lambda () (cl--generic-isnot-nnm-p cnm))))
201 ;; The old EIEIO code did not signal an error when there are methods
202 ;; applicable but only of the before/after kind. So if we add a :before
203 ;; or :after, make sure there's a matching dummy primary.
204 (when (and (memq kind '(:before :after))
205 ;; FIXME: Use `cl-find-method'?
206 (not (cl-find-method method ()
207 (mapcar (lambda (arg)
208 (if (consp arg) (nth 1 arg) t))
210 (cl-generic-define-method method () specializers t
211 (lambda (cnm &rest args)
212 (if (cl--generic-isnot-nnm-p cnm)
216 ;; Compatibility with code which tries to catch `no-method-definition' errors.
217 (push 'no-method-definition (get 'cl-no-applicable-method 'error-conditions))
219 (defun generic-p (fname) (not (null (cl--generic fname))))
221 (defun no-next-method (&rest args)
222 (declare (obsolete cl-no-next-method "25.1"))
223 (apply #'cl-no-next-method 'unknown nil args))
225 (defun no-applicable-method (object method &rest args)
226 (declare (obsolete cl-no-applicable-method "25.1"))
227 (apply #'cl-no-applicable-method method object args))
229 (define-obsolete-function-alias 'call-next-method 'cl-call-next-method "25.1")
230 (defun next-method-p ()
231 (declare (obsolete cl-next-method-p "25.1"))
232 ;; EIEIO's `next-method-p' just returned nil when called in an
234 (message "next-method-p called outside of a primary or around method")
238 (defun eieio-defmethod (method args)
239 "Obsolete work part of an old version of the `defmethod' macro."
240 (declare (obsolete cl-defmethod "24.1"))
241 (eval `(defmethod ,method ,@args))
245 (defun eieio-defgeneric (method doc-string)
246 "Obsolete work part of an old version of the `defgeneric' macro."
247 (declare (obsolete cl-defgeneric "24.1"))
248 (eval `(defgeneric ,method (x) ,@(if doc-string `(,doc-string))))
253 (defun eieio-defclass (cname superclasses slots options)
254 (declare (obsolete eieio-defclass-internal "25.1"))
255 (eval `(defclass ,cname ,superclasses ,slots ,@options)))
259 ;; generated-autoload-file: "eieio-core.el"
262 (provide 'eieio-compat)
264 ;;; eieio-compat.el ends here