emacs-guix/elisp/guix-location.el

;;; guix-location.el --- Package locations

;; Copyright © 2016–2017 Alex Kost <alezost@gmail.com>

;; This file is part of Emacs-Guix.

;; Emacs-Guix 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.
;;
;; Emacs-Guix 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 Emacs-Guix.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; This file provides the code to work with locations of Guix packages.

;;; Code:

(require 'cl-lib)
(require 'guix-repl)
(require 'guix-read)
(require 'guix-guile)

(defun guix-package-location (id-or-name)
  "Return location of a package with ID-OR-NAME.
For the meaning of location, see `guix-find-location'."
  (guix-eval-read (guix-make-guile-expression
                   'package-location-string id-or-name)))

;;;###autoload
(defun guix-find-location (location &optional directory)
  "Go to LOCATION of a package.
LOCATION is a string of the form:

  \"FILE:LINE:COLUMN\"

If FILE is relative, it is considered to be relative to
DIRECTORY (if it is specified and exists).

Interactively, prompt for LOCATION.  With prefix argument, prompt
for DIRECTORY as well."
  (interactive
   (list (guix-read-package-location)
         (guix-read-directory)))
  (cl-multiple-value-bind (file line column)
      (split-string location ":")
    (let* ((file-name (expand-file-name file (or directory
                                                 guix-directory)))
           (file-name (if (file-exists-p file-name)
                          file-name
                        (guix-eval-read
                         (guix-make-guile-expression
                          'search-load-path file)))))
      (unless file-name         ; not found in Guile %load-path
        (error "Package location file not found: %s" file))
      (find-file file-name))
    (when (and line column)
      (let ((line   (string-to-number line))
            (column (string-to-number column)))
        (goto-char (point-min))
        (forward-line (- line 1))
        (move-to-column column)
        (recenter 1)))))

;;;###autoload
(defun guix-edit (id-or-name &optional directory)
  "Edit (go to location of) package with ID-OR-NAME.
See `guix-find-location' for the meaning of package location and
DIRECTORY.
Interactively, with prefix argument, prompt for DIRECTORY."
  (interactive
   (list (guix-read-package-name)
         (guix-read-directory)))
  (let ((loc (guix-package-location id-or-name)))
    (if loc
        (guix-find-location loc directory)
      (message "Couldn't find package location."))))

(provide 'guix-location)

;;; guix-location.el ends here