(defun feature-symbols (feature)
"Return the file and list of symbols associated with a given FEATURE."
(catch 'foundit
(mapcar
(function (lambda (x)
(if (member (cons 'provide feature) (cdr x))
(throw 'foundit x))))
load-history)
nil))
(defun feature-file (feature)
"Return the file name from which a given FEATURE was loaded.
Actually, return the load argument, if any; this is sometimes the name of a
Lisp file without an extension. If the feature came from an eval-buffer on
a buffer with no associated file, or an eval-region, return nil."
(if (not (featurep feature))
(error "%s is not a currently loaded feature" (symbol-name feature))
(car (feature-symbols feature))))
(defun file-provides (file)
"Return the list of features provided by FILE."
(let ((symbols (cdr (assoc file load-history))) (provides nil))
(mapcar
(function (lambda (x)
(if (and (consp x) (eq (car x) 'provide))
(setq provides (cons (cdr x) provides)))))
symbols)
provides
))
(defun file-requires (file)
"Return the list of features required by FILE."
(let ((symbols (cdr (assoc file load-history))) (requires nil))
(mapcar
(function (lambda (x)
(if (and (consp x) (eq (car x) 'require))
(setq requires (cons (cdr x) requires)))))
symbols)
requires
))
(defun file-set-intersect (p q)
(let ((ret nil))
(mapcar
(function (lambda (x) (if (memq x q) (setq ret (cons x ret)))))
p)
ret
))
(defun file-dependents (file)
"Return the list of loaded libraries that depend on FILE.
This can include FILE itself."
(let ((provides (file-provides file)) (dependents nil))
(mapcar
(function (lambda (x)
(if (file-set-intersect provides (file-requires (car x)))
(setq dependents (cons (car x) dependents)))))
load-history)
dependents
))
(defun read-feature (prompt)
"Read a feature name \(string\) from the minibuffer.
Prompt with PROMPT and completing from `features', and
return the feature \(symbol\)."
(intern (completing-read prompt
(mapcar (function (lambda (feature)
(list (symbol-name feature))))
features)
nil t)))
(defvar loadhist-hook-functions
'(after-change-function after-change-functions
after-insert-file-functions auto-fill-function before-change-function
before-change-functions blink-paren-function
buffer-access-fontify-functions command-line-functions
comment-indent-function kill-buffer-query-functions
kill-emacs-query-functions lisp-indent-function
redisplay-end-trigger-functions temp-buffer-show-function
window-scroll-functions window-size-change-functions
write-region-annotate-functions)
"A list of special hooks from the `Standard Hooks' node of the Lisp manual.
These are symbols with hook-type values whose names don't end in
`-hook' or `-hooks', from which `unload-feature' tries to remove
pertinent symbols.")
(defun unload-feature (feature &optional force)
"Unload the library that provided FEATURE, restoring all its autoloads.
If the feature is required by any other loaded code, and optional FORCE
is nil, raise an error."
(interactive (list (read-feature "Feature: ")))
(if (not (featurep feature))
(error "%s is not a currently loaded feature" (symbol-name feature)))
(if (not force)
(let* ((file (feature-file feature))
(dependents (delete file (copy-sequence (file-dependents file)))))
(if dependents
(error "Loaded libraries %s depend on %s"
(prin1-to-string dependents) file))))
(let* ((flist (feature-symbols feature))
(file (car flist))
(unload-hook (intern-soft (concat (symbol-name feature)
"-unload-hook"))))
(if unload-hook
(run-hooks unload-hook)
(mapatoms
(lambda (x)
(if (or (and (boundp x) (consp (symbol-value x))
(string-match "-hooks?\\'" (symbol-name x)))
(and (fboundp x) (memq x loadhist-hook-functions)))
(mapcar (lambda (y) (remove-hook x y))
(cdr flist))))))
(mapcar
(lambda (x)
(cond ((stringp x) nil)
((consp x)
(if (eq (car x) 'provide)
(setq features (delq (cdr x) features))))
((boundp x) (makunbound x))
((fboundp x)
(fmakunbound x)
(let ((aload (get x 'autoload)))
(if aload (fset x (cons 'autoload aload)))))))
(cdr flist))
(let ((elt (assoc file load-history)))
(setq load-history (delq elt load-history)))))
(provide 'loadhist)