guix-devel/emacs/guix-external.el

73 lines
2.3 KiB
EmacsLisp

;;; guix-external.el --- External programs -*- lexical-binding: t -*-
;; Copyright © 2015 Alex Kost <alezost@gmail.com>
;; This file is part of GNU Guix.
;; GNU 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.
;; GNU 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 this program. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; This file provides auxiliary code for running external programs.
;;; Code:
(defgroup guix-external nil
"Settings for external programs."
:group 'guix)
(defcustom guix-dot-program (executable-find "dot")
"Name of the 'dot' executable."
:type 'string
:group 'guix-external)
(defcustom guix-dot-default-arguments
'("-Tpng")
"Default arguments for 'dot' program."
:type '(repeat string)
:group 'guix-external)
(defcustom guix-dot-file-name-function #'guix-png-file-name
"Function used to define a file name of a temporary 'dot' file.
The function is called without arguments."
:type '(choice (function-item guix-png-file-name)
(function :tag "Other function"))
:group 'guix-external)
(defun guix-dot-arguments (output-file &rest args)
"Return a list of dot arguments for writing a graph into OUTPUT-FILE.
If ARGS is nil, use `guix-dot-default-arguments'."
(or guix-dot-program
(error (concat "Couldn't find 'dot'.\n"
"Set guix-dot-program to a proper value")))
(apply #'list
guix-dot-program
(concat "-o" output-file)
(or args guix-dot-default-arguments)))
(defun guix-dot-file-name ()
"Call `guix-dot-file-name-function'."
(funcall guix-dot-file-name-function))
(defun guix-png-file-name ()
"Return '.png' file name in the `temporary-file-directory'."
(concat (make-temp-name
(concat (file-name-as-directory temporary-file-directory)
"guix-emacs-graph-"))
".png"))
(provide 'guix-external)
;;; guix-external.el ends here