[bpt/emacs.git] / lisp / eshell / esh-opt.el

;;; esh-opt.el --- command options processing

;; Copyright (C) 1999-2012  Free Software Foundation, Inc.

;; Author: John Wiegley <johnw@gnu.org>

;; This file is part of GNU Emacs.

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

;;; Commentary:

;;; Code:

(provide 'esh-opt)

(eval-when-compile (require 'esh-ext))

(defgroup eshell-opt nil
  "The options processing code handles command argument parsing for
Eshell commands implemented in Lisp."
  :tag "Command options processing"
  :group 'eshell)

;;; User Functions:

(defmacro eshell-eval-using-options (name macro-args options &rest body-forms)
  "Process NAME's MACRO-ARGS using a set of command line OPTIONS.
After doing so, stores settings in local symbols as declared by OPTIONS;
then evaluates BODY-FORMS -- assuming all was OK.

OPTIONS is a list, beginning with one or more elements of the form:
\(SHORT LONG VALUE SYMBOL HELP-STRING)
Each of these elements represents a particular command-line switch.

SHORT is either nil, or a character that can be used as a switch -SHORT.
LONG is either nil, or a string that can be used as a switch --LONG.
At least one of SHORT and LONG must be non-nil.
VALUE is the value associated with the option.  It can be either:
  t   - the option needs a value to be specified after the switch;
  nil - the option is given the value t;
  anything else - specifies the actual value for the option.
SYMBOL is either nil, or the name of the Lisp symbol that will be bound
to VALUE.  A nil SYMBOL calls `eshell-show-usage', and so is appropriate
for a \"--help\" type option.
HELP-STRING is a documentation string for the option.

Any remaining elements of OPTIONS are :KEYWORD arguments.  Some take
arguments, some do not.  The recognized :KEYWORDS are:

:external STRING
  STRING is an external command to run if there are unknown switches.

:usage STRING
  STRING is the initial part of the command's documentation string.
  It appears before the options are listed.

:post-usage STRING
  STRING is an optional trailing part of the command's documentation string.
  It appears after the options, but before the final part of the
  documentation about the associated external command (if there is one).

:show-usage
  If present, then show the usage message if the command is called with no
  arguments.

:preserve-args
  If present, do not pass MACRO-ARGS through `eshell-flatten-list'
and `eshell-stringify-list'.

For example, OPTIONS might look like:

  '((?C  nil         nil multi-column    \"multi-column display\")
    (nil \"help\"      nil nil             \"show this usage display\")
    (?r  \"reverse\"   nil reverse-list    \"reverse order while sorting\")
    :external \"ls\"
    :usage \"[OPTION]... [FILE]...
  List information about the FILEs (the current directory by default).
  Sort entries alphabetically across.\")

`eshell-eval-using-options' returns the value of the last form in
BODY-FORMS.  If instead an external command is run (because of
an unknown option), the tag `eshell-external' will be thrown with
the new process for its value.

Lastly, any remaining arguments will be available in a locally
interned variable `args' (created using a `let' form)."
  (declare (debug (form form sexp body)))
  `(let ((temp-args
	  ,(if (memq ':preserve-args (cadr options))
	       macro-args
	     (list 'eshell-stringify-list
		   (list 'eshell-flatten-list macro-args)))))
     (let ,(append (delq nil (mapcar (lambda (opt)
				       (and (listp opt) (nth 3 opt)))
				     (cadr options)))
		   '(usage-msg last-value ext-command args))
       (eshell-do-opt ,name ,options (quote ,body-forms)))))

;;; Internal Functions:

(defvar temp-args)
(defvar last-value)
(defvar usage-msg)
(defvar ext-command)
;; Documented part of the interface; see eshell-eval-using-options.
(defvar args)

(defun eshell-do-opt (name options body-forms)
  "Helper function for `eshell-eval-using-options'.
This code doesn't really need to be macro expanded everywhere."
  (setq args temp-args)
  (if (setq
       ext-command
       (catch 'eshell-ext-command
	 (when (setq
		usage-msg
		(catch 'eshell-usage
		  (setq last-value nil)
		  (if (and (= (length args) 0)
			   (memq ':show-usage options))
		      (throw 'eshell-usage
			     (eshell-show-usage name options)))
		  (setq args (eshell-process-args name args options)
			last-value (eval (append (list 'progn)
						 body-forms)))
		  nil))
	   (error "%s" usage-msg))))
      (throw 'eshell-external
             (eshell-external-command ext-command args))
    last-value))

(defun eshell-show-usage (name options)
  "Display the usage message for NAME, using OPTIONS."
  (let ((usage (format "usage: %s %s\n\n" name
		       (cadr (memq ':usage options))))
	(extcmd (memq ':external options))
	(post-usage (memq ':post-usage options))
	had-option)
    (while options
      (when (listp (car options))
	(let ((opt (car options)))
	  (setq had-option t)
	  (cond ((and (nth 0 opt)
		      (nth 1 opt))
		 (setq usage
		       (concat usage
			       (format "    %-20s %s\n"
				       (format "-%c, --%s" (nth 0 opt)
					       (nth 1 opt))
				       (nth 4 opt)))))
		((nth 0 opt)
		 (setq usage
		       (concat usage
			       (format "    %-20s %s\n"
				       (format "-%c" (nth 0 opt))
				       (nth 4 opt)))))
		((nth 1 opt)
		 (setq usage
		       (concat usage
			       (format "    %-20s %s\n"
				       (format "    --%s" (nth 1 opt))
				       (nth 4 opt)))))
		(t (setq had-option nil)))))
      (setq options (cdr options)))
    (if post-usage
	(setq usage (concat usage (and had-option "\n")
			    (cadr post-usage))))
    (when extcmd
      (setq extcmd (eshell-search-path (cadr extcmd)))
      (if extcmd
	  (setq usage
		(concat usage
			(format "
This command is implemented in Lisp.  If an unrecognized option is
passed to this command, the external version '%s'
will be called instead." extcmd)))))
    (throw 'eshell-usage usage)))

(defun eshell-set-option (name ai opt options)
  "Using NAME's remaining args (index AI), set the OPT within OPTIONS.
If the option consumes an argument for its value, the argument list
will be modified."
  (if (not (nth 3 opt))
      (eshell-show-usage name options)
    (if (eq (nth 2 opt) t)
	(if (> ai (length args))
	    (error "%s: missing option argument" name)
	  (set (nth 3 opt) (nth ai args))
	  (if (> ai 0)
	      (setcdr (nthcdr (1- ai) args) (nthcdr (1+ ai) args))
	    (setq args (cdr args))))
      (set (nth 3 opt) (or (nth 2 opt) t)))))

(defun eshell-process-option (name switch kind ai options)
  "For NAME, process SWITCH (of type KIND), from args at index AI.
The SWITCH will be looked up in the set of OPTIONS.

SWITCH should be either a string or character.  KIND should be the
integer 0 if it's a character, or 1 if it's a string.

The SWITCH is then be matched against OPTIONS.  If no matching handler
is found, and an :external command is defined (and available), it will
be called; otherwise, an error will be triggered to say that the
switch is unrecognized."
  (let* ((opts options)
	 found)
    (while opts
      (if (and (listp (car opts))
		 (nth kind (car opts))
		 (if (= kind 0)
		     (eq switch (nth kind (car opts)))
		   (string= switch (nth kind (car opts)))))
	  (progn
	    (eshell-set-option name ai (car opts) options)
	    (setq found t opts nil))
	(setq opts (cdr opts))))
    (unless found
      (let ((extcmd (memq ':external options)))
	(when extcmd
	  (setq extcmd (eshell-search-path (cadr extcmd)))
	  (if extcmd
	      (throw 'eshell-ext-command extcmd)
	    (if (characterp switch)
		(error "%s: unrecognized option -%c" name switch)
	      (error "%s: unrecognized option --%s" name switch))))))))

(defun eshell-process-args (name args options)
  "Process the given ARGS using OPTIONS.
This assumes that symbols have been intern'd by `eshell-eval-using-options'."
  (let ((ai 0) arg)
    (while (< ai (length args))
      (setq arg (nth ai args))
      (if (not (and (stringp arg)
		    (string-match "^-\\(-\\)?\\(.*\\)" arg)))
	  (setq ai (1+ ai))
	(let* ((dash (match-string 1 arg))
	       (switch (match-string 2 arg)))
	  (if (= ai 0)
	      (setq args (cdr args))
	    (setcdr (nthcdr (1- ai) args) (nthcdr (1+ ai) args)))
	  (if dash
	      (if (> (length switch) 0)
		  (eshell-process-option name switch 1 ai options)
		(setq ai (length args)))
	    (let ((len (length switch))
		  (index 0))
	      (while (< index len)
		(eshell-process-option name (aref switch index) 0 ai options)
		(setq index (1+ index)))))))))
  args)

;;; esh-opt.el ends here
Commit	Line	Data
60370d40	1	;;; esh-opt.el --- command options processing
affbf647	2
acaf905b	3	;; Copyright (C) 1999-2012 Free Software Foundation, Inc.
affbf647	4
7de5b421 GM	5	;; Author: John Wiegley <johnw@gnu.org>
7de5b421 GM	6
affbf647 GM	7	;; This file is part of GNU Emacs.
affbf647 GM	8
4ee57b2a	9	;; GNU Emacs is free software: you can redistribute it and/or modify
affbf647	10	;; it under the terms of the GNU General Public License as published by
4ee57b2a GM	11	;; the Free Software Foundation, either version 3 of the License, or
4ee57b2a GM	12	;; (at your option) any later version.
affbf647 GM	13
	14	;; GNU Emacs is distributed in the hope that it will be useful,
	15	;; but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	;; GNU General Public License for more details.
	18
	19	;; You should have received a copy of the GNU General Public License
4ee57b2a	20	;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
affbf647	21
4e6cc05c GM	22	;;; Commentary:
4e6cc05c GM	23
8c7309fe GM	24	;;; Code:
8c7309fe GM	25
affbf647 GM	26	(provide 'esh-opt)
affbf647 GM	27
4e6cc05c	28	(eval-when-compile (require 'esh-ext))
affbf647 GM	29
	30	(defgroup eshell-opt nil
	31	"The options processing code handles command argument parsing for
	32	Eshell commands implemented in Lisp."
	33	:tag "Command options processing"
	34	:group 'eshell)
	35
affbf647 GM	36	;;; User Functions:
affbf647 GM	37
4e05e67e	38	(defmacro eshell-eval-using-options (name macro-args options &rest body-forms)
affbf647	39	"Process NAME's MACRO-ARGS using a set of command line OPTIONS.
4e05e67e GM	40	After doing so, stores settings in local symbols as declared by OPTIONS;
4e05e67e GM	41	then evaluates BODY-FORMS -- assuming all was OK.
affbf647	42
4e05e67e GM	43	OPTIONS is a list, beginning with one or more elements of the form:
	44	\(SHORT LONG VALUE SYMBOL HELP-STRING)
	45	Each of these elements represents a particular command-line switch.
	46
	47	SHORT is either nil, or a character that can be used as a switch -SHORT.
	48	LONG is either nil, or a string that can be used as a switch --LONG.
	49	At least one of SHORT and LONG must be non-nil.
	50	VALUE is the value associated with the option. It can be either:
	51	t - the option needs a value to be specified after the switch;
	52	nil - the option is given the value t;
	53	anything else - specifies the actual value for the option.
	54	SYMBOL is either nil, or the name of the Lisp symbol that will be bound
	55	to VALUE. A nil SYMBOL calls `eshell-show-usage', and so is appropriate
	56	for a \"--help\" type option.
	57	HELP-STRING is a documentation string for the option.
	58
	59	Any remaining elements of OPTIONS are :KEYWORD arguments. Some take
	60	arguments, some do not. The recognized :KEYWORDS are:
	61
	62	:external STRING
	63	STRING is an external command to run if there are unknown switches.
	64
	65	:usage STRING
	66	STRING is the initial part of the command's documentation string.
	67	It appears before the options are listed.
	68
	69	:post-usage STRING
	70	STRING is an optional trailing part of the command's documentation string.
	71	It appears after the options, but before the final part of the
	72	documentation about the associated external command (if there is one).
	73
	74	:show-usage
	75	If present, then show the usage message if the command is called with no
	76	arguments.
	77
	78	:preserve-args
	79	If present, do not pass MACRO-ARGS through `eshell-flatten-list'
	80	and `eshell-stringify-list'.
	81
	82	For example, OPTIONS might look like:
affbf647 GM	83
	84	'((?C nil nil multi-column \"multi-column display\")
	85	(nil \"help\" nil nil \"show this usage display\")
	86	(?r \"reverse\" nil reverse-list \"reverse order while sorting\")
	87	:external \"ls\"
	88	:usage \"[OPTION]... [FILE]...
	89	List information about the FILEs (the current directory by default).
	90	Sort entries alphabetically across.\")
	91
	92	`eshell-eval-using-options' returns the value of the last form in
4e05e67e GM	93	BODY-FORMS. If instead an external command is run (because of
	94	an unknown option), the tag `eshell-external' will be thrown with
	95	the new process for its value.
affbf647 GM	96
	97	Lastly, any remaining arguments will be available in a locally
	98	interned variable `args' (created using a `let' form)."
0d182a34	99	(declare (debug (form form sexp body)))
affbf647 GM	100	`(let ((temp-args
	101	,(if (memq ':preserve-args (cadr options))
	102	macro-args
	103	(list 'eshell-stringify-list
	104	(list 'eshell-flatten-list macro-args)))))
18d05bed GM	105	(let ,(append (delq nil (mapcar (lambda (opt)
	106	(and (listp opt) (nth 3 opt)))
	107	(cadr options)))
affbf647 GM	108	'(usage-msg last-value ext-command args))
	109	(eshell-do-opt ,name ,options (quote ,body-forms)))))
	110
	111	;;; Internal Functions:
	112
1a32899d GM	113	(defvar temp-args)
	114	(defvar last-value)
	115	(defvar usage-msg)
	116	(defvar ext-command)
5ca67338	117	;; Documented part of the interface; see eshell-eval-using-options.
1a32899d	118	(defvar args)
affbf647 GM	119
	120	(defun eshell-do-opt (name options body-forms)
	121	"Helper function for `eshell-eval-using-options'.
	122	This code doesn't really need to be macro expanded everywhere."
	123	(setq args temp-args)
	124	(if (setq
	125	ext-command
	126	(catch 'eshell-ext-command
	127	(when (setq
	128	usage-msg
	129	(catch 'eshell-usage
	130	(setq last-value nil)
	131	(if (and (= (length args) 0)
	132	(memq ':show-usage options))
	133	(throw 'eshell-usage
	134	(eshell-show-usage name options)))
	135	(setq args (eshell-process-args name args options)
	136	last-value (eval (append (list 'progn)
	137	body-forms)))
	138	nil))
c009ca06	139	(error "%s" usage-msg))))
affbf647	140	(throw 'eshell-external
0d182a34	141	(eshell-external-command ext-command args))
affbf647 GM	142	last-value))
	143
	144	(defun eshell-show-usage (name options)
	145	"Display the usage message for NAME, using OPTIONS."
	146	(let ((usage (format "usage: %s %s\n\n" name
	147	(cadr (memq ':usage options))))
	148	(extcmd (memq ':external options))
	149	(post-usage (memq ':post-usage options))
	150	had-option)
	151	(while options
	152	(when (listp (car options))
	153	(let ((opt (car options)))
	154	(setq had-option t)
	155	(cond ((and (nth 0 opt)
	156	(nth 1 opt))
	157	(setq usage
	158	(concat usage
	159	(format " %-20s %s\n"
	160	(format "-%c, --%s" (nth 0 opt)
	161	(nth 1 opt))
	162	(nth 4 opt)))))
	163	((nth 0 opt)
	164	(setq usage
	165	(concat usage
	166	(format " %-20s %s\n"
	167	(format "-%c" (nth 0 opt))
	168	(nth 4 opt)))))
	169	((nth 1 opt)
	170	(setq usage
	171	(concat usage
	172	(format " %-20s %s\n"
	173	(format " --%s" (nth 1 opt))
	174	(nth 4 opt)))))
	175	(t (setq had-option nil)))))
	176	(setq options (cdr options)))
	177	(if post-usage
	178	(setq usage (concat usage (and had-option "\n")
	179	(cadr post-usage))))
	180	(when extcmd
	181	(setq extcmd (eshell-search-path (cadr extcmd)))
	182	(if extcmd
	183	(setq usage
	184	(concat usage
	185	(format "
	186	This command is implemented in Lisp. If an unrecognized option is
	187	passed to this command, the external version '%s'
	188	will be called instead." extcmd)))))
	189	(throw 'eshell-usage usage)))
	190
	191	(defun eshell-set-option (name ai opt options)
	192	"Using NAME's remaining args (index AI), set the OPT within OPTIONS.
	193	If the option consumes an argument for its value, the argument list
	194	will be modified."
	195	(if (not (nth 3 opt))
	196	(eshell-show-usage name options)
	197	(if (eq (nth 2 opt) t)
	198	(if (> ai (length args))
	199	(error "%s: missing option argument" name)
	200	(set (nth 3 opt) (nth ai args))
	201	(if (> ai 0)
	202	(setcdr (nthcdr (1- ai) args) (nthcdr (1+ ai) args))
	203	(setq args (cdr args))))
	204	(set (nth 3 opt) (or (nth 2 opt) t)))))
	205
206	(defun eshell-process-option (name switch kind ai options)
207	"For NAME, process SWITCH (of type KIND), from args at index AI.
208	The SWITCH will be looked up in the set of OPTIONS.
209
210	SWITCH should be either a string or character. KIND should be the
211	integer 0 if it's a character, or 1 if it's a string.
212
213	The SWITCH is then be matched against OPTIONS. If no matching handler
214	is found, and an :external command is defined (and available), it will
215	be called; otherwise, an error will be triggered to say that the
216	switch is unrecognized."
217	(let* ((opts options)
218	found)
219	(while opts
220	(if (and (listp (car opts))
221	(nth kind (car opts))
222	(if (= kind 0)
223	(eq switch (nth kind (car opts)))
224	(string= switch (nth kind (car opts)))))
225	(progn
226	(eshell-set-option name ai (car opts) options)
227	(setq found t opts nil))
228	(setq opts (cdr opts))))
229	(unless found
230	(let ((extcmd (memq ':external options)))
231	(when extcmd
232	(setq extcmd (eshell-search-path (cadr extcmd)))
233	(if extcmd
234	(throw 'eshell-ext-command extcmd)
8bd3a3ad	235	(if (characterp switch)
affbf647 GM	236	(error "%s: unrecognized option -%c" name switch)
	237	(error "%s: unrecognized option --%s" name switch))))))))
	238
	239	(defun eshell-process-args (name args options)
	240	"Process the given ARGS using OPTIONS.
4e05e67e	241	This assumes that symbols have been intern'd by `eshell-eval-using-options'."
affbf647 GM	242	(let ((ai 0) arg)
	243	(while (< ai (length args))
	244	(setq arg (nth ai args))
	245	(if (not (and (stringp arg)
	246	(string-match "^-\\(-\\)?\\(.*\\)" arg)))
	247	(setq ai (1+ ai))
	248	(let* ((dash (match-string 1 arg))
	249	(switch (match-string 2 arg)))
	250	(if (= ai 0)
	251	(setq args (cdr args))
	252	(setcdr (nthcdr (1- ai) args) (nthcdr (1+ ai) args)))
	253	(if dash
	254	(if (> (length switch) 0)
	255	(eshell-process-option name switch 1 ai options)
	256	(setq ai (length args)))
	257	(let ((len (length switch))
	258	(index 0))
	259	(while (< index len)
	260	(eshell-process-option name (aref switch index) 0 ai options)
	261	(setq index (1+ index)))))))))
	262	args)
	263
affbf647	264	;;; esh-opt.el ends here