1 ;;; eieio-compat.el --- Compatibility with Older EIEIO versions -*- lexical-binding:t -*-
3 ;; Copyright (C) 1995-1996, 1998-2016 Free Software Foundation, Inc.
5 ;; Author: Eric M. Ludlam <zappo@gnu.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 3 of the License, or
14 ;; (at your option) any later version.
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. If not, see <http://www.gnu.org/licenses/>.
26 ;; Backward compatibility definition of old EIEIO functions in
27 ;; terms of newer equivalent.
29 ;; The main elements are the old EIEIO `defmethod' and `defgeneric' which are
30 ;; now implemented on top of cl-generic. The differences we have to
32 ;; - EIEIO's :static methods (turned into a new `eieio--static' specializer).
33 ;; - EIEIO's support for `call-next-method' and `next-method-p' instead of
34 ;; `cl-next-method-p' and `cl-call-next-method' (simple matter of renaming).
35 ;; - Different errors are signaled.
36 ;; - EIEIO's defgeneric does not reset the function.
37 ;; - EIEIO's no-next-method and no-applicable-method can't be aliases of
38 ;; cl-generic's namesakes since they have different calling conventions,
39 ;; which means that packages that (defmethod no-next-method ..) don't work.
40 ;; - EIEIO's `call-next-method' and `next-method-p' had dynamic scope whereas
41 ;; cl-generic's `cl-next-method-p' and `cl-call-next-method' are lexically
49 (put 'eieio--defalias 'byte-hunk-handler
50 #'byte-compile-file-form-defalias) ;;(get 'defalias 'byte-hunk-handler)
52 (defun eieio--defalias (name body)
53 "Like `defalias', but with less side-effects.
54 More specifically, it has no side-effects at all when the new function
55 definition is the same (`eq') as the old one."
56 (cl-assert (not (symbolp body)))
57 (while (and (fboundp name) (symbolp (symbol-function name)))
58 ;; Follow aliases, so methods applied to obsolete aliases still work.
59 (setq name (symbol-function name)))
60 (unless (and (fboundp name)
61 (eq (symbol-function name) body))
62 (defalias name body)))
65 (defmacro defgeneric (method args &optional doc-string)
66 "Create a generic function METHOD.
67 DOC-STRING is the base documentation for this class. A generic
68 function has no body, as its purpose is to decide which method body
69 is appropriate to use. Uses `defmethod' to create methods, and calls
70 `defgeneric' for you. With this implementation the ARGS are
71 currently ignored. You can use `defgeneric' to apply specialized
72 top level documentation to a method."
73 (declare (doc-string 3) (obsolete cl-defgeneric "25.1"))
74 `(eieio--defalias ',method
75 (eieio--defgeneric-init-form
77 ,(if doc-string (help-add-fundoc-usage doc-string args)))))
80 (defmacro defmethod (method &rest args)
81 "Create a new METHOD through `defgeneric' with ARGS.
83 The optional second argument KEY is a specifier that
84 modifies how the method is called, including:
85 :before - Method will be called before the :primary
86 :primary - The default if not specified
87 :after - Method will be called after the :primary
88 :static - First arg could be an object or class
89 The next argument is the ARGLIST. The ARGLIST specifies the arguments
90 to the method as with `defun'. The first argument can have a type
92 ((VARNAME CLASS) ARG2 ...)
93 where VARNAME is the name of the local variable for the method being
94 created. The CLASS is a class symbol for a class made with `defclass'.
95 A DOCSTRING comes after the ARGLIST, and is optional.
96 All the rest of the args are the BODY of the method. A method will
97 return the value of the last form in the BODY.
101 (defmethod mymethod [:before | :primary | :after | :static]
102 ((typearg class-name) arg2 &optional opt &rest rest)
105 (declare (doc-string 3) (obsolete cl-defmethod "25.1")
107 (&define ; this means we are defining something
108 [&or name ("setf" :name setf name)]
109 ;; ^^ This is the methods symbol
110 [ &optional symbolp ] ; this is key :before etc
112 [ &optional stringp ] ; documentation string
113 def-body ; part to be debugged
115 (let* ((key (if (keywordp (car args)) (pop args)))
118 (fargs (if (consp arg1)
119 (cons (car arg1) (cdr params))
121 (class (if (consp arg1) (nth 1 arg1)))
122 (code `(lambda ,fargs ,@(cdr args))))
124 ;; Make sure there is a generic and the byte-compiler sees it.
125 (defgeneric ,method ,args)
126 (eieio--defmethod ',method ',key ',class #',code))))
128 (defun eieio--generic-static-symbol-specializers (tag &rest _)
129 (cl-assert (or (null tag) (eieio--class-p tag)))
130 (when (eieio--class-p tag)
131 (let ((superclasses (eieio--generic-subclass-specializers tag))
133 (dolist (superclass superclasses)
134 (push superclass specializers)
135 (push `(eieio--static ,(cadr superclass)) specializers))
136 (nreverse specializers))))
138 (cl-generic-define-generalizer eieio--generic-static-symbol-generalizer
139 ;; Give it a slightly higher priority than `subclass' so that the
140 ;; interleaved list comes before subclass's non-interleaved list.
141 61 (lambda (name &rest _) `(and (symbolp ,name) (cl--find-class ,name)))
142 #'eieio--generic-static-symbol-specializers)
143 (cl-generic-define-generalizer eieio--generic-static-object-generalizer
144 ;; Give it a slightly higher priority than `class' so that the
145 ;; interleaved list comes before the class's non-interleaved list.
146 51 #'cl--generic-struct-tag
147 (lambda (tag &rest _)
148 (and (symbolp tag) (boundp tag) (setq tag (symbol-value tag))
150 (let ((superclasses (eieio--class-precedence-list tag))
152 (dolist (superclass superclasses)
153 (setq superclass (eieio--class-name superclass))
154 (push superclass specializers)
155 (push `(eieio--static ,superclass) specializers))
156 (nreverse specializers)))))
158 (cl-defmethod cl-generic-generalizers ((_specializer (head eieio--static)))
159 (list eieio--generic-static-symbol-generalizer
160 eieio--generic-static-object-generalizer))
163 (defun eieio--defgeneric-init-form (method doc-string)
164 (if doc-string (put method 'function-documentation doc-string))
165 (if (memq method '(no-next-method no-applicable-method))
166 (symbol-function method)
167 (let ((generic (cl-generic-ensure-function method)))
168 (symbol-function (cl--generic-name generic)))))
171 (defun eieio--defmethod (method kind argclass code)
172 (setq kind (intern (downcase (symbol-name kind))))
173 (let* ((specializer (if (not (eq kind :static))
176 `(eieio--static ,argclass)))
177 (uses-cnm (not (memq kind '(:before :after))))
178 (specializers `((arg ,specializer)))
180 ;; Backward compatibility for `no-next-method' and
181 ;; `no-applicable-method', which have slightly different calling
182 ;; convention than their cl-generic counterpart.
185 (setq method 'cl-no-next-method)
186 (setq specializers `(generic method ,@specializers))
187 (lambda (_generic _method &rest args) (apply code args)))
188 (`no-applicable-method
189 (setq method 'cl-no-applicable-method)
190 (setq specializers `(generic ,@specializers))
191 (lambda (generic arg &rest args) (apply code arg generic args)))
193 (cl-generic-define-method
194 method (unless (memq kind '(nil :primary)) (list kind))
195 specializers uses-cnm
197 (let* ((docstring (documentation code 'raw))
198 (args (help-function-arglist code 'preserve-names))
199 (doc-only (if docstring
200 (let ((split (help-split-fundoc docstring nil)))
201 (if split (cdr split) docstring)))))
202 (lambda (cnm &rest args)
204 (help-add-fundoc-usage doc-only (cons 'cl-cnm args)))
205 (cl-letf (((symbol-function 'call-next-method) cnm)
206 ((symbol-function 'next-method-p)
207 (lambda () (cl--generic-isnot-nnm-p cnm))))
210 ;; The old EIEIO code did not signal an error when there are methods
211 ;; applicable but only of the before/after kind. So if we add a :before
212 ;; or :after, make sure there's a matching dummy primary.
213 (when (and (memq kind '(:before :after))
214 ;; FIXME: Use `cl-find-method'?
215 (not (cl-find-method method ()
216 (mapcar (lambda (arg)
217 (if (consp arg) (nth 1 arg) t))
219 (cl-generic-define-method method () specializers t
220 (lambda (cnm &rest args)
221 (if (cl--generic-isnot-nnm-p cnm)
225 ;; Compatibility with code which tries to catch `no-method-definition' errors.
226 (push 'no-method-definition (get 'cl-no-applicable-method 'error-conditions))
228 (defun generic-p (fname) (not (null (cl--generic fname))))
230 (defun no-next-method (&rest args)
231 (declare (obsolete cl-no-next-method "25.1"))
232 (apply #'cl-no-next-method 'unknown nil args))
234 (defun no-applicable-method (object method &rest args)
235 (declare (obsolete cl-no-applicable-method "25.1"))
236 (apply #'cl-no-applicable-method method object args))
238 (define-obsolete-function-alias 'call-next-method 'cl-call-next-method "25.1")
239 (defun next-method-p ()
240 (declare (obsolete cl-next-method-p "25.1"))
241 ;; EIEIO's `next-method-p' just returned nil when called in an
243 (message "next-method-p called outside of a primary or around method")
247 (defun eieio-defmethod (method args)
248 "Obsolete work part of an old version of the `defmethod' macro."
249 (declare (obsolete cl-defmethod "24.1"))
250 (eval `(defmethod ,method ,@args))
254 (defun eieio-defgeneric (method doc-string)
255 "Obsolete work part of an old version of the `defgeneric' macro."
256 (declare (obsolete cl-defgeneric "24.1"))
257 (eval `(defgeneric ,method (x) ,@(if doc-string `(,doc-string))))
262 (defun eieio-defclass (cname superclasses slots options)
263 (declare (obsolete eieio-defclass-internal "25.1"))
264 (eval `(defclass ,cname ,superclasses ,slots ,@options)))
268 ;; generated-autoload-file: "eieio-loaddefs.el"
271 (provide 'eieio-compat)
273 ;;; eieio-compat.el ends here