emacs/guix-external.el

   1 ;;; guix-external.el --- External programs  -*- lexical-binding: t -*-
   2
   3 ;; Copyright © 2015 Alex Kost <alezost@gmail.com>
   4
   5 ;; This file is part of GNU Guix.
   6
   7 ;; GNU Guix is free software; you can redistribute it and/or modify
   8 ;; it under the terms of the GNU General Public License as published by
   9 ;; the Free Software Foundation, either version 3 of the License, or
  10 ;; (at your option) any later version.
  11
  12 ;; GNU Guix is distributed in the hope that it will be useful,
  13 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ;; GNU General Public License for more details.
  16
  17 ;; You should have received a copy of the GNU General Public License
  18 ;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19
  20 ;;; Commentary:
  21
  22 ;; This file provides auxiliary code for running external programs.
  23
  24 ;;; Code:
  25
  26 (require 'guix-config)
  27
  28 (defgroup guix-external nil
  29   "Settings for external programs."
  30   :group 'guix)
  31
  32 (defcustom guix-guile-program guix-config-guile-program
  33   "Name of the 'guile' executable used for Guix REPL.
  34 May be either a string (the name of the executable) or a list of
  35 strings of the form:
  36
  37   (NAME . ARGS)
  38
  39 Where ARGS is a list of arguments to the guile program."
  40   :type 'string
  41   :group 'guix-external)
  42
  43 (defcustom guix-dot-program
  44   (if (file-name-absolute-p guix-config-dot-program)
  45       guix-config-dot-program
  46     (executable-find "dot"))
  47   "Name of the 'dot' executable."
  48   :type 'string
  49   :group 'guix-external)
  50
  51 (defcustom guix-dot-default-arguments
  52   '("-Tpng")
  53   "Default arguments for 'dot' program."
  54   :type '(repeat string)
  55   :group 'guix-external)
  56
  57 (defcustom guix-dot-file-name-function #'guix-png-file-name
  58   "Function used to define a file name of a temporary 'dot' file.
  59 The function is called without arguments."
  60   :type '(choice (function-item guix-png-file-name)
  61                  (function :tag "Other function"))
  62   :group 'guix-external)
  63
  64 (defun guix-dot-arguments (output-file &rest args)
  65   "Return a list of dot arguments for writing a graph into OUTPUT-FILE.
  66 If ARGS is nil, use `guix-dot-default-arguments'."
  67   (or guix-dot-program
  68       (error (concat "Couldn't find 'dot'.\n"
  69                      "Set guix-dot-program to a proper value")))
  70   (apply #'list
  71          guix-dot-program
  72          (concat "-o" output-file)
  73          (or args guix-dot-default-arguments)))
  74
  75 (defun guix-dot-file-name ()
  76   "Call `guix-dot-file-name-function'."
  77   (funcall guix-dot-file-name-function))
  78
  79 (defun guix-png-file-name ()
  80   "Return '.png' file name in the `temporary-file-directory'."
  81   (concat (make-temp-name
  82            (concat (file-name-as-directory temporary-file-directory)
  83                    "guix-emacs-graph-"))
  84           ".png"))
  85
  86 (provide 'guix-external)
  87
  88 ;;; guix-external.el ends here