1 ;;; haskell-ghci.el --- A GHCi interaction mode
3 ;; Copyright (C) 2004, 2005 Free Software Foundation, Inc.
4 ;; Copyright (C) 2001 Chris Webb
5 ;; Copyright (C) 1998, 1999 Guy Lapalme
7 ;; Keywords: inferior mode, GHCi interaction mode, Haskell
9 ;;; This file is not part of GNU Emacs.
11 ;; This file is free software; you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation; either version 2, or (at your option)
16 ;; This file is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs; see the file COPYING. If not, write to the
23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
24 ;; Boston, MA 02111-1307, USA.
31 ;; To send a Haskell buffer to another buffer running a GHCi
34 ;; This mode is derived from version 1.1 of Guy Lapalme's
35 ;; haskell-hugs.el, which can be obtained from:
37 ;; http://www.iro.umontreal.ca/~lapalme/Hugs-interaction.html
39 ;; This in turn was adapted from Chris Van Humbeeck's hugs-mode.el,
40 ;; which can be obtained from:
42 ;; http://www-i2.informatik.rwth-aachen.de/Forschung/FP/Haskell/hugs-mode.el
47 ;; To use with Moss and Thorn's haskell-mode.el
49 ;; http://www.haskell.org/haskell-mode
51 ;; add this to .emacs:
53 ;; (add-hook haskell-mode-hook 'turn-on-haskell-ghci)
58 ;; The name of the GHCi interpreter is in haskell-ghci-program-name.
60 ;; Arguments can be sent to the GHCi interpreter when it is started by
61 ;; setting haskell-ghci-program-args (empty by default) to a list of
62 ;; string args to pass it. This value can be set interactively by
63 ;; calling C-c C-s with an argument (i.e. C-u C-c C-s).
65 ;; `haskell-ghci-hook' is invoked in the *ghci* buffer once GHCi is
68 ;; All functions/variables start with `turn-{on,off}-haskell-ghci' or
73 (defgroup haskell-ghci nil
74 "Major mode for interacting with an inferior GHCi session."
76 :prefix "haskell-ghci-")
78 (defun turn-on-haskell-ghci ()
79 "Turn on Haskell interaction mode with a GHCi interpreter running in an
80 another Emacs buffer named *ghci*.
81 Maps the following commands in the haskell keymap:
82 \\<haskell-mode-map>\\[haskell-ghci-start-process] to create the GHCi buffer and start a GHCi process in it.
83 \\[haskell-ghci-load-file] to save the current buffer and load it by sending the :load command to GHCi.
84 \\[haskell-ghci-reload-file] to send the :reload command to GHCi without saving the buffer.
85 \\[haskell-ghci-show-ghci-buffer] to show the GHCi buffer and go to it."
87 (local-set-key "\C-c\C-s" 'haskell-ghci-start-process)
88 (local-set-key "\C-c\C-l" 'haskell-ghci-load-file)
89 (local-set-key "\C-c\C-r" 'haskell-ghci-reload-file)
90 (local-set-key "\C-c\C-n" 'haskell-ghci-locate-next-error)
91 (local-set-key "\C-c\C-b" 'haskell-ghci-show-ghci-buffer))
93 (defun turn-off-haskell-ghci ()
94 "Turn off Haskell interaction mode with a GHCi interpreter within a buffer."
96 (local-unset-key "\C-c\C-s")
97 (local-unset-key "\C-c\C-l")
98 (local-unset-key "\C-c\C-r")
99 (local-unset-key "\C-c\C-b"))
101 (defun haskell-ghci-mode ()
102 "Major mode for interacting with an inferior GHCi session.
104 The commands available from within a Haskell script are:
105 \\<haskell-mode-map>\\[haskell-ghci-start-process] to create the GHCi buffer and start a GHCi process in it.
106 \\[haskell-ghci-load-file] to save the current buffer and load it by sending the :load command to GHCi.
107 \\[haskell-ghci-reload-file] to send the :reload command to GHCi without saving the buffer.
108 \\[haskell-ghci-show-ghci-buffer] to show the GHCi buffer and go to it.
110 \\<haskell-ghci-mode-map>Commands:
111 \\[comint-send-input] after end of GHCi output sends line as input to GHCi.
112 \\[comint-send-input] before end of GHCI output copies rest of line and sends it to GHCI as input.
113 \\[comint-kill-input] and \\[backward-kill-word] are kill commands, imitating normal Unix input editing.
114 \\[comint-interrupt-subjob] interrupts the comint or its current subjob if any.
115 \\[comint-stop-subjob] stops, likewise. \\[comint-quit-subjob] sends quit signal."
118 (setq major-mode 'haskell-ghci-mode)
119 (setq mode-name "Haskell GHCi")
120 (if haskell-ghci-mode-map
122 (setq haskell-ghci-mode-map (copy-keymap comint-mode-map)))
123 (use-local-map haskell-ghci-mode-map))
131 (defvar haskell-ghci-process nil
132 "The active GHCi subprocess corresponding to current buffer.")
134 (defvar haskell-ghci-process-buffer nil
135 "*Buffer used for communication with GHCi subprocess for current buffer.")
137 (defcustom haskell-ghci-program-name "ghci"
138 "*The name of the GHCi interpreter program."
140 :group 'haskell-ghci)
142 (defcustom haskell-ghci-program-args nil
143 "*A list of string args to pass when starting the GHCi interpreter."
144 :type '(repeat string)
145 :group 'haskell-ghci)
147 (defvar haskell-ghci-load-end nil
148 "Position of the end of the last load command.")
150 (defvar haskell-ghci-error-pos nil
151 "Position of the end of the last load command.")
153 (defvar haskell-ghci-send-end nil
154 "Position of the end of the last send command.")
156 (defun haskell-ghci-start-process (arg)
157 "Start a GHCi process and invoke `haskell-ghci-hook' if not nil.
158 Prompt for a list of args if called with an argument."
161 ;; XXX [CDW] Fix to use more natural 'string' version of the
162 ;; XXX arguments rather than a sexp.
163 (setq haskell-ghci-program-args
164 (read-minibuffer (format "List of args for %s:"
165 haskell-ghci-program-name)
166 (prin1-to-string haskell-ghci-program-args))))
168 ;; Start the GHCi process in a new comint buffer.
169 (message "Starting GHCi process `%s'." haskell-ghci-program-name)
170 (setq haskell-ghci-process-buffer
172 "ghci" haskell-ghci-program-name nil
173 haskell-ghci-program-args))
174 (setq haskell-ghci-process
175 (get-buffer-process haskell-ghci-process-buffer))
177 ;; Select GHCi buffer temporarily.
178 (set-buffer haskell-ghci-process-buffer)
180 (make-local-variable 'shell-cd-regexp)
181 (make-local-variable 'shell-dirtrackp)
183 ;; Track directory changes using the `:cd' command.
184 (setq shell-cd-regexp ":cd")
185 (setq shell-dirtrackp t)
186 (add-hook 'comint-input-filter-functions 'shell-directory-tracker)
188 ;; GHCi prompt should be of the form `ModuleName> '.
189 (setq comint-prompt-regexp "^\\*?[A-Z][\\._a-zA-Z0-9]*\\( \\*?[A-Z][\\._a-zA-Z0-9]*\\)*> ")
191 ;; History syntax of comint conflicts with Haskell, e.g. !!, so better
193 (setq comint-input-autoexpand nil)
194 (run-hooks 'haskell-ghci-hook)
196 ;; Clear message area.
199 (defun haskell-ghci-wait-for-output ()
200 "Wait until output arrives and go to the last input."
202 (goto-char comint-last-input-end)
203 (not (re-search-forward comint-prompt-regexp nil t)))
204 (accept-process-output haskell-ghci-process)))
206 (defun haskell-ghci-send (&rest string)
207 "Send `haskell-ghci-process' the arguments (one or more strings).
208 A newline is sent after the strings and they are inserted into the
209 current buffer after the last output."
210 (haskell-ghci-wait-for-output) ; wait for prompt
211 (goto-char (point-max)) ; position for this input
212 (apply 'insert string)
214 (setq haskell-ghci-send-end (marker-position comint-last-input-end)))
216 (defun haskell-ghci-go (load-command cd)
217 "Save the current buffer and load its file into the GHCi process.
218 The first argument LOAD-COMMAND specifies how the file should be
219 loaded: as a new file (\":load \") or as a reload (\":reload \").
221 If the second argument CD is non-nil, change directory in the GHCi
222 process to the current buffer's directory before loading the file.
224 If the variable `haskell-ghci-command' is set then its value will be
225 sent to the GHCi process after the load command. This can be used for a
226 top-level expression to evaluate."
227 (hack-local-variables) ; in case they've changed
229 (let ((file (if (string-equal load-command ":load ")
230 (concat "\"" buffer-file-name "\"")
232 (dir (expand-file-name default-directory))
233 (cmd (and (boundp 'haskell-ghci-command)
235 (if (stringp haskell-ghci-command)
237 (symbol-name haskell-ghci-command)))))
238 (if (and haskell-ghci-process-buffer
239 (eq (process-status haskell-ghci-process) 'run))
240 ;; Ensure the GHCi buffer is selected.
241 (set-buffer haskell-ghci-process-buffer)
242 ;; Start Haskell-GHCi process.
243 (haskell-ghci-start-process nil))
245 (if cd (haskell-ghci-send (concat ":cd " dir)))
246 ;; Wait until output arrives and go to the last input.
247 (haskell-ghci-wait-for-output)
248 (haskell-ghci-send load-command file)
249 ;; Error message search starts from last load command.
250 (setq haskell-ghci-load-end (marker-position comint-last-input-end))
251 (setq haskell-ghci-error-pos haskell-ghci-load-end)
252 (if cmd (haskell-ghci-send cmd))
253 ;; Wait until output arrives and go to the last input.
254 (haskell-ghci-wait-for-output)))
256 (defun haskell-ghci-load-file (cd)
257 "Save a ghci buffer file and load its file.
258 If CD (prefix argument if interactive) is non-nil, change directory in
259 the GHCi process to the current buffer's directory before loading the
260 file. If there is an error, set the cursor at the error line otherwise
261 show the *ghci* buffer."
263 (haskell-ghci-gen-load-file ":load " cd))
265 (defun haskell-ghci-reload-file (cd)
266 "Save a ghci buffer file and load its file.
267 If CD (prefix argument if interactive) is non-nil, change the GHCi
268 process to the current buffer's directory before loading the file.
269 If there is an error, set the cursor at the error line otherwise show
272 (haskell-ghci-gen-load-file ":reload " cd))
274 (defun haskell-ghci-gen-load-file (cmd cd)
275 "Save a ghci buffer file and load its file or reload depending on CMD.
276 If CD is non-nil, change the process to the current buffer's directory
277 before loading the file. If there is an error, set the cursor at the
278 error line otherwise show the *ghci* buffer."
280 ;; Execute (re)load command.
281 (save-excursion (haskell-ghci-go cmd cd))
283 ;; Show *ghci* buffer.
284 (pop-to-buffer haskell-ghci-process-buffer)
285 (goto-char haskell-ghci-load-end)
287 ;; Did we finish loading without error?
288 (if (re-search-forward
289 "^Ok, modules loaded" nil t)
290 (progn (goto-char (point-max))
292 (message "There were no errors."))
294 ;; Something went wrong. If possible, be helpful and pinpoint the
295 ;; first error in the file whilst leaving the error visible in the
297 (goto-char haskell-ghci-load-end)
298 (haskell-ghci-locate-next-error)))
301 (defun haskell-ghci-locate-next-error ()
302 "Go to the next error shown in the *ghci* buffer."
304 (if (buffer-live-p haskell-ghci-process-buffer)
305 (progn (pop-to-buffer haskell-ghci-process-buffer)
306 (goto-char haskell-ghci-error-pos)
307 (if (re-search-forward
308 "^[^\/]*\\([^:\n]+\\):\\([0-9]+\\)" nil t)
309 (let ((efile (buffer-substring (match-beginning 1)
311 (eline (string-to-int
312 (buffer-substring (match-beginning 2)
316 (setq haskell-ghci-error-pos (point))
317 (message "GHCi error on line %d of %s."
318 eline (file-name-nondirectory efile))
319 (if (file-exists-p efile)
320 (progn (find-file-other-window efile)
324 ;; We got an error without a file and line number, so put the
325 ;; point at end of the *ghci* buffer ready to deal with it.
326 (goto-char (point-max))
328 (message "No more errors found.")))
329 (message "No *ghci* buffer found.")))
331 (defun haskell-ghci-show-ghci-buffer ()
332 "Go to the *ghci* buffer."
334 (if (or (not haskell-ghci-process-buffer)
335 (not (buffer-live-p haskell-ghci-process-buffer)))
336 (haskell-ghci-start-process nil))
337 (pop-to-buffer haskell-ghci-process-buffer))
339 (provide 'haskell-ghci)
341 ;;; haskell-ghci.el ends here