1 ;;; cl-preloaded.el --- Preloaded part of the CL library -*- lexical-binding: t; -*-
3 ;; Copyright (C) 2015 Free Software Foundation, Inc
5 ;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
7 ;; This file is part of GNU Emacs.
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 3 of the License, or
12 ;; (at your option) any later version.
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.
19 ;; You should have received a copy of the GNU General Public License
20 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
24 ;; The cl-defstruct macro is full of circularities, since it uses the
25 ;; cl-structure-class type (and its accessors) which is defined with itself,
26 ;; and it setups a default parent (cl-structure-object) which is also defined
27 ;; with cl-defstruct, and to make things more interesting, the class of
28 ;; cl-structure-object is of course an object of type cl-structure-class while
29 ;; cl-structure-class's parent is cl-structure-object.
30 ;; Furthermore, the code generated by cl-defstruct generally assumes that the
31 ;; parent will be loaded when the child is loaded. But at the same time, the
32 ;; expectation is that structs defined with cl-defstruct do not need cl-lib at
33 ;; run-time, which means that the `cl-structure-object' parent can't be in
34 ;; cl-lib but should be preloaded. So here's this preloaded circular setup.
38 (eval-when-compile (require 'cl-lib
))
39 (eval-when-compile (require 'cl-macs
)) ;For cl--struct-class.
41 ;; The `assert' macro from the cl package signals
42 ;; `cl-assertion-failed' at runtime so always define it.
43 (define-error 'cl-assertion-failed
(purecopy "Assertion failed"))
45 (defun cl--assertion-failed (form &optional string sargs args
)
47 (debug `(cl-assertion-failed ,form
,string
,@sargs
))
49 (apply #'error string
(append sargs args
))
50 (signal 'cl-assertion-failed
`(,form
,@sargs
)))))
52 ;; When we load this (compiled) file during pre-loading, the cl--struct-class
53 ;; code below will need to access the `cl-struct' info, since it's considered
54 ;; already as its parent (because `cl-struct' was defined while the file was
55 ;; compiled). So let's temporarily setup a fake.
56 (defvar cl-struct-cl-structure-object-tags nil
)
57 (unless (cl--find-class 'cl-structure-object
)
58 (setf (cl--find-class 'cl-structure-object
) 'dummy
))
60 (fset 'cl--make-slot-desc
61 ;; To break circularity, we pre-define the slot constructor by hand.
62 ;; It's redefined a bit further down as part of the cl-defstruct of
63 ;; cl--slot-descriptor.
64 ;; BEWARE: Obviously, it's important to keep the two in sync!
65 (lambda (name &optional initform type props
)
66 (vector 'cl-struct-cl-slot-descriptor
67 name initform type props
)))
69 (defun cl--struct-get-class (name)
70 (or (if (not (symbolp name
)) name
)
72 (if (not (get name
'cl-struct-type
))
73 ;; FIXME: Add a conversion for `eieio--class' so we can
74 ;; create a cl-defstruct that inherits from an eieio class?
75 (error "%S is not a struct name" name
)
76 ;; Backward compatibility with a defstruct compiled with a version
77 ;; cl-defstruct from Emacs<25. Convert to new format.
78 (let ((tag (intern (format "cl-struct-%s" name
)))
79 (type-and-named (get name
'cl-struct-type
))
80 (descs (get name
'cl-struct-slots
)))
81 (cl-struct-define name nil
(get name
'cl-struct-include
)
82 (unless (and (eq (car type-and-named
) 'vector
)
83 (null (cadr type-and-named
))
84 (assq 'cl-tag-slot descs
))
88 (intern (format "cl-struct-%s-tags" name
))
90 (get name
'cl-struct-print
))
91 (cl--find-class name
)))))
93 (defun cl--plist-remove (plist member
)
97 ((eq plist member
) (cddr plist
))
98 (t `(,(car plist
) ,(cadr plist
) ,@(cl--plist-remove (cddr plist
) member
)))))
100 (defun cl--struct-register-child (parent tag
)
101 ;; Can't use (cl-typep parent 'cl-structure-class) at this stage
102 ;; because `cl-structure-class' is defined later.
103 (while (vectorp parent
)
104 (add-to-list (cl--struct-class-children-sym parent
) tag
)
105 ;; Only register ourselves as a child of the leftmost parent since structs
106 ;; can only only have one parent.
107 (setq parent
(car (cl--struct-class-parents parent
)))))
110 (defun cl-struct-define (name docstring parent type named slots children-sym
112 (cl-assert (or type
(not named
)))
113 (if (boundp children-sym
)
114 (add-to-list children-sym tag
)
115 (set children-sym
(list tag
)))
116 (and (null type
) (eq (caar slots
) 'cl-tag-slot
)
117 ;; Hide the tag slot from "standard" (i.e. non-`type'd) structs.
118 (setq slots
(cdr slots
)))
119 (let* ((parent-class (when parent
(cl--struct-get-class parent
)))
121 (index-table (make-hash-table :test
'eq
:size n
))
122 (vslots (let ((v (make-vector n nil
))
124 (offset (if type
0 1)))
126 (let* ((props (cddr slot
))
127 (typep (plist-member props
:type
))
128 (type (if typep
(cadr typep
) t
)))
129 (aset v i
(cl--make-slot-desc
130 (car slot
) (nth 1 slot
)
131 type
(cl--plist-remove props typep
))))
132 (puthash (car slot
) (+ i offset
) index-table
)
135 (class (cl--struct-new-class
137 (unless (symbolp parent-class
) (list parent-class
))
138 type named vslots index-table children-sym tag print
)))
139 (unless (symbolp parent-class
)
140 (let ((pslots (cl--struct-class-slots parent-class
)))
141 (or (>= n
(length pslots
))
143 (dotimes (i (length pslots
))
144 (unless (eq (cl--slot-descriptor-name (aref pslots i
))
145 (cl--slot-descriptor-name (aref vslots i
)))
148 (error "Included struct %S has changed since compilation of %S"
150 (add-to-list 'current-load-list
`(define-type .
,name
))
151 (cl--struct-register-child parent-class tag
)
153 (eval `(defconst ,tag
',class
) t
)
154 ;; In the cl-generic support, we need to be able to check
155 ;; if a vector is a cl-struct object, without knowing its particular type.
156 ;; So we use the (otherwise) unused function slots of the tag symbol
157 ;; to put a special witness value, to make the check easy and reliable.
158 (fset tag
:quick-object-witness-check
))
159 (setf (cl--find-class name
) class
)))
161 (cl-defstruct (cl-structure-class
162 (:conc-name cl--struct-class-
)
163 (:predicate cl--struct-class-p
)
165 (:constructor cl--struct-new-class
166 (name docstring parents type named slots index-table
167 children-sym tag print
))
169 "The type of CL structs descriptors."
170 ;; The first few fields here are actually inherited from cl--class, but we
171 ;; have to define this one before, to break the circularity, so we manually
172 ;; list the fields here and later "backpatch" cl--class as the parent.
173 ;; BEWARE: Obviously, it's indispensable to keep these two structs in sync!
174 (name nil
:type symbol
) ;The type name.
175 (docstring nil
:type string
)
176 (parents nil
:type
(list-of cl--class
)) ;The included struct.
177 (slots nil
:type
(vector cl--slot-descriptor
))
178 (index-table nil
:type hash-table
)
179 (tag nil
:type symbol
) ;Placed in cl-tag-slot. Holds the struct-class object.
180 (type nil
:type
(memq (vector list
)))
181 (named nil
:type bool
)
182 (print nil
:type bool
)
183 (children-sym nil
:type symbol
) ;This sym's value holds the tags of children.
186 (cl-defstruct (cl-structure-object
187 (:predicate cl-struct-p
)
190 "The root parent of all \"normal\" CL structs")
192 (setq cl--struct-default-parent
'cl-structure-object
)
194 (cl-defstruct (cl-slot-descriptor
195 (:conc-name cl--slot-descriptor-
)
197 (:constructor cl--make-slot-descriptor
198 (name &optional initform type props
))
199 (:copier cl--copy-slot-descriptor-1
))
200 ;; FIXME: This is actually not used yet, for circularity reasons!
201 "Descriptor of structure slot."
202 name
;Attribute name (symbol).
205 ;; Extra properties, kept in an alist, can include:
206 ;; :documentation, :protection, :custom, :label, :group, :printer.
207 (props nil
:type alist
))
209 (defun cl--copy-slot-descriptor (slot)
210 (let ((new (cl--copy-slot-descriptor-1 slot
)))
211 (cl-callf copy-alist
(cl--slot-descriptor-props new
))
214 (cl-defstruct (cl--class
217 "Type of descriptors for any kind of structure-like data."
218 ;; Intended to be shared between defstruct and defclass.
219 (name nil
:type symbol
) ;The type name.
220 (docstring nil
:type string
)
221 ;; For structs there can only be one parent, but when EIEIO classes inherit
222 ;; from cl--class, we'll need this to hold a list.
223 (parents nil
:type
(list-of cl--class
))
224 (slots nil
:type
(vector cl-slot-descriptor
))
225 (index-table nil
:type hash-table
))
228 (let ((sc-slots (cl--struct-class-slots (cl--find-class 'cl-structure-class
)))
229 (c-slots (cl--struct-class-slots (cl--find-class 'cl--class
)))
231 (dotimes (i (length c-slots
))
232 (let ((sc-slot (aref sc-slots i
))
233 (c-slot (aref c-slots i
)))
234 (unless (eq (cl--slot-descriptor-name sc-slot
)
235 (cl--slot-descriptor-name c-slot
))
239 ;; Close the recursion between cl-structure-object and cl-structure-class.
240 (setf (cl--struct-class-parents (cl--find-class 'cl-structure-class
))
241 (list (cl--find-class 'cl--class
)))
242 (cl--struct-register-child
243 (cl--find-class 'cl--class
)
244 (cl--struct-class-tag (cl--find-class 'cl-structure-class
)))
246 (cl-assert (cl--find-class 'cl-structure-class
))
247 (cl-assert (cl--find-class 'cl-structure-object
))
248 (cl-assert (cl-struct-p (cl--find-class 'cl-structure-class
)))
249 (cl-assert (cl-struct-p (cl--find-class 'cl-structure-object
)))
250 (cl-assert (cl--class-p (cl--find-class 'cl-structure-class
)))
251 (cl-assert (cl--class-p (cl--find-class 'cl-structure-object
)))
253 ;; Make sure functions defined with cl-defsubst can be inlined even in
254 ;; packages which do not require CL. We don't put an autoload cookie
255 ;; directly on that function, since those cookies only go to cl-loaddefs.
256 (autoload 'cl--defsubst-expand
"cl-macs")
257 ;; Autoload, so autoload.el and font-lock can use it even when CL
259 (put 'cl-defun
'doc-string-elt
3)
260 (put 'cl-defmacro
'doc-string-elt
3)
261 (put 'cl-defsubst
'doc-string-elt
3)
262 (put 'cl-defstruct
'doc-string-elt
2)
264 (provide 'cl-preloaded
)
265 ;;; cl-preloaded.el ends here