;;; elisp-slime-nav.el --- Make M-. and M-, work in elisp like they do in slime
;; Copyright (C) 2016 Steve Purcell
;; Author: Steve Purcell <steve@sanityinc.com>
;; Keywords: navigation slime elisp emacs-lisp
;; URL: https://github.com/purcell/elisp-slime-nav
;; Package-Version: 20160128.1109
;; Package-X-Original-Version: 0
;; Package-Requires: ((cl-lib "0.2"))
;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with this program. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;;
;; This package provides Slime's convenient "M-." and "M-," navigation
;; in `emacs-lisp-mode', together with an elisp equivalent of
;; `slime-describe-symbol', bound by default to `C-c C-d d`.
;;
;; When the main functions are given a prefix argument, they will
;; prompt for the symbol upon which to operate.
;;
;; Usage:
;;
;; Enable the package in elisp and ielm modes as follows:
;;
;; (require 'elisp-slime-nav) ;; optional if installed via package.el
;; (dolist (hook '(emacs-lisp-mode-hook ielm-mode-hook))
;; (add-hook hook 'turn-on-elisp-slime-nav-mode))
;;
;; Known issues:
;;
;; When navigating into Emacs' C source, "M-," will not be bound to
;; the same command, but "M-*" will typically do the trick.
;;
;;; Code:
(require 'etags)
(require 'help-mode)
(defvar elisp-slime-nav-mode-map
(let ((map (make-sparse-keymap)))
(define-key map (kbd "M-.") 'elisp-slime-nav-find-elisp-thing-at-point)
(define-key map (kbd "M-,") 'pop-tag-mark)
(define-key map (kbd "C-c C-d d") 'elisp-slime-nav-describe-elisp-thing-at-point)
(define-key map (kbd "C-c C-d C-d") 'elisp-slime-nav-describe-elisp-thing-at-point)
map))
;;;###autoload
(define-minor-mode elisp-slime-nav-mode
"Enable Slime-style navigation of elisp symbols using M-. and M-,"
nil " SliNav" elisp-slime-nav-mode-map)
;;;###autoload
(defun turn-on-elisp-slime-nav-mode ()
"Explicitly enable `elisp-slime-nav-mode'."
(elisp-slime-nav-mode 1))
(defun elisp-slime-nav--all-navigable-symbol-names ()
"Return a list of strings for the symbols to which navigation is possible."
(let ((result '()))
(mapatoms
(lambda (x)
(when (or (fboundp x) (boundp x) (symbol-plist x) (facep x))
(push (symbol-name x) result))))
result))
(defun elisp-slime-nav--read-symbol-at-point ()
"Return the symbol at point as a string.
If `current-prefix-arg' is not nil, the user is prompted for the symbol."
(let* ((sym-at-point (symbol-at-point))
(at-point (and sym-at-point (symbol-name sym-at-point))))
(if (or current-prefix-arg (null at-point))
(completing-read "Symbol: "
(elisp-slime-nav--all-navigable-symbol-names)
nil t nil nil at-point)
at-point)))
;;;###autoload
(defun elisp-slime-nav-find-elisp-thing-at-point (sym-name)
"Find the elisp thing at point, be it a function, variable, library or face.
With a prefix arg, or if there is no thing at point, prompt for
the symbol to jump to.
Argument SYM-NAME is the thing to find."
(interactive (list (elisp-slime-nav--read-symbol-at-point)))
(when sym-name
(let ((sym (intern sym-name)))
(message "Searching for %s..." sym-name)
(if (fboundp 'xref-push-marker-stack)
(xref-push-marker-stack)
(with-no-warnings
(ring-insert find-tag-marker-ring (point-marker))))
(cond
((fboundp sym)
(find-function sym))
((boundp sym)
(find-variable sym))
((or (featurep sym) (locate-library sym-name))
(find-library sym-name))
((facep sym)
(find-face-definition sym))
(t
(pop-tag-mark)
(error "Don't know how to find '%s'" sym))))))
;;;###autoload
(defun elisp-slime-nav-describe-elisp-thing-at-point (sym-name)
"Display the full documentation of the elisp thing at point.
The named subject may be a function, variable, library or face.
With a prefix arg, or if there is not \"thing\" at point, prompt
for the symbol to jump to.
Argument SYM-NAME is the thing to find."
(interactive (list (elisp-slime-nav--read-symbol-at-point)))
(if (fboundp 'describe-symbol)
(describe-symbol (intern sym-name))
(with-no-warnings
(help-xref-interned (intern sym-name)))))
(provide 'elisp-slime-nav)
;; Local Variables:
;; indent-tabs-mode: nil
;; End:
;;; elisp-slime-nav.el ends here
