1 ;;; parse-time.el --- parsing time strings
3 ;; Copyright (C) 1996, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
4 ;; 2008, 2009 Free Software Foundation, Inc.
6 ;; Author: Erik Naggum <erik@naggum.no>
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs 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 3 of the License, or
14 ;; (at your option) any later version.
16 ;; GNU Emacs 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. If not, see <http://www.gnu.org/licenses/>.
26 ;; With the introduction of the `encode-time', `decode-time', and
27 ;; `format-time-string' functions, dealing with time became simpler in
28 ;; Emacs. However, parsing time strings is still largely a matter of
29 ;; heuristics and no common interface has been designed.
31 ;; `parse-time-string' parses a time in a string and returns a list of 9
32 ;; values, just like `decode-time', where unspecified elements in the
33 ;; string are returned as nil. `encode-time' may be applied on these
34 ;; values to obtain an internal time value.
38 (eval-when-compile (require 'cl)) ;and ah ain't kiddin' 'bout it
40 (defvar parse-time-syntax (make-vector 256 nil))
41 (defvar parse-time-digits (make-vector 256 nil))
43 ;; Byte-compiler warnings
44 (defvar parse-time-elt)
45 (defvar parse-time-val)
47 (unless (aref parse-time-digits ?0)
48 (loop for i from ?0 to ?9
49 do (aset parse-time-digits i (- i ?0))))
51 (unless (aref parse-time-syntax ?0)
52 (loop for i from ?0 to ?9
53 do (aset parse-time-syntax i ?0))
54 (loop for i from ?A to ?Z
55 do (aset parse-time-syntax i ?A))
56 (loop for i from ?a to ?z
57 do (aset parse-time-syntax i ?a))
58 (aset parse-time-syntax ?+ 1)
59 (aset parse-time-syntax ?- -1)
60 (aset parse-time-syntax ?: ?d))
62 (defsubst digit-char-p (char)
63 (aref parse-time-digits char))
65 ;; Note: the function definition differs from the one in Emacs
66 ;; in order to keep the compatibility with XEmacs.
67 (defsubst parse-time-string-chars (char)
68 (and (< char (length parse-time-syntax))
69 (aref parse-time-syntax char)))
71 (put 'parse-error 'error-conditions '(parse-error error))
72 (put 'parse-error 'error-message "Parsing error")
74 (defsubst parse-integer (string &optional start end)
75 "[CL] Parse and return the integer in STRING, or nil if none."
79 (end (or end (length string))))
81 (let ((sign (aref string index)))
82 (if (or (eq sign ?+) (eq sign ?-))
83 (setq sign (parse-time-string-chars sign)
86 (while (and (< index end)
87 (setq digit (digit-char-p (aref string index))))
88 (setq integer (+ (* integer 10) digit)
91 (signal 'parse-error `("not an integer"
92 ,(substring string (or start 0) end)))
95 (defun parse-time-tokenize (string)
96 "Tokenize STRING into substrings."
104 (while (and (< index end) ;skip invalid characters
105 (not (setq c (parse-time-string-chars (aref string index)))))
107 (setq start index all-digits (eq c ?0))
108 (while (and (< (incf index) end) ;scan valid characters
109 (setq c (parse-time-string-chars (aref string index))))
110 (setq all-digits (and all-digits (eq c ?0))))
112 (push (if all-digits (parse-integer string start index)
113 (substring string start index))
117 (defvar parse-time-months '(("jan" . 1) ("feb" . 2) ("mar" . 3)
118 ("apr" . 4) ("may" . 5) ("jun" . 6)
119 ("jul" . 7) ("aug" . 8) ("sep" . 9)
120 ("oct" . 10) ("nov" . 11) ("dec" . 12)
121 ("january" . 1) ("february" . 2)
122 ("march" . 3) ("april" . 4) ("june" . 6)
123 ("july" . 7) ("august" . 8)
124 ("september" . 9) ("october" . 10)
125 ("november" . 11) ("december" . 12)))
126 (defvar parse-time-weekdays '(("sun" . 0) ("mon" . 1) ("tue" . 2)
127 ("wed" . 3) ("thu" . 4) ("fri" . 5)
128 ("sat" . 6) ("sunday" . 0) ("monday" . 1)
129 ("tuesday" . 2) ("wednesday" . 3)
130 ("thursday" . 4) ("friday" . 5)
132 (defvar parse-time-zoneinfo `(("z" 0) ("ut" 0) ("gmt" 0)
133 ("pst" ,(* -8 3600)) ("pdt" ,(* -7 3600) t)
134 ("mst" ,(* -7 3600)) ("mdt" ,(* -6 3600) t)
135 ("cst" ,(* -6 3600)) ("cdt" ,(* -5 3600) t)
136 ("est" ,(* -5 3600)) ("edt" ,(* -4 3600) t))
137 "(zoneinfo seconds-off daylight-savings-time-p)")
139 (defvar parse-time-rules
140 `(((6) parse-time-weekdays)
142 ((4) parse-time-months)
145 ,#'(lambda () (and (stringp parse-time-elt)
146 (= (length parse-time-elt) 8)
147 (= (aref parse-time-elt 2) ?:)
148 (= (aref parse-time-elt 5) ?:)))
150 ((8 7) parse-time-zoneinfo
151 ,#'(lambda () (car parse-time-val))
152 ,#'(lambda () (cadr parse-time-val)))
155 (and (stringp parse-time-elt)
156 (= 5 (length parse-time-elt))
157 (or (= (aref parse-time-elt 0) ?+)
158 (= (aref parse-time-elt 0) ?-))))
159 ,#'(lambda () (* 60 (+ (parse-integer parse-time-elt 3 5)
160 (* 60 (parse-integer parse-time-elt 1 3)))
161 (if (= (aref parse-time-elt 0) ?-) -1 1))))
163 ,#'(lambda () (and (stringp parse-time-elt)
164 (= (length parse-time-elt) 10)
165 (= (aref parse-time-elt 4) ?-)
166 (= (aref parse-time-elt 7) ?-)))
169 ,#'(lambda () (and (stringp parse-time-elt)
170 (= (length parse-time-elt) 5)
171 (= (aref parse-time-elt 2) ?:)))
172 [0 2] [3 5] ,#'(lambda () 0))
174 ,#'(lambda () (and (stringp parse-time-elt)
175 (= (length parse-time-elt) 4)
176 (= (aref parse-time-elt 1) ?:)))
177 [0 1] [2 4] ,#'(lambda () 0))
179 ,#'(lambda () (and (stringp parse-time-elt)
180 (= (length parse-time-elt) 7)
181 (= (aref parse-time-elt 1) ?:)))
183 ((5) (50 110) ,#'(lambda () (+ 1900 parse-time-elt)))
184 ((5) (0 49) ,#'(lambda () (+ 2000 parse-time-elt))))
185 "(slots predicate extractor...)")
186 ;;;###autoload(put 'parse-time-rules 'risky-local-variable t)
189 (defun parse-time-string (string)
190 "Parse the time-string STRING into (SEC MIN HOUR DAY MON YEAR DOW DST TZ).
191 The values are identical to those of `decode-time', but any values that are
192 unknown are returned as nil."
193 (let ((time (list nil nil nil nil nil nil nil nil nil))
194 (temp (parse-time-tokenize (downcase string))))
196 (let ((parse-time-elt (pop temp))
197 (rules parse-time-rules)
199 (while (and rules (not exit))
200 (let* ((rule (pop rules))
202 (predicate (pop rule))
204 (when (and (not (nth (car slots) time)) ;not already set
205 (setq parse-time-val (cond ((and (consp predicate)
206 (not (eq (car predicate)
208 (and (numberp parse-time-elt)
209 (<= (car predicate) parse-time-elt)
210 (<= parse-time-elt (cadr predicate))
213 (cdr (assoc parse-time-elt
214 (symbol-value predicate))))
215 ((funcall predicate)))))
218 (let ((new-val (and rule
219 (let ((this (pop rule)))
223 (aref this 0) (aref this 1))
225 (rplaca (nthcdr (pop slots) time)
226 (or new-val parse-time-val)))))))))
229 (provide 'parse-time)
231 ;; arch-tag: 07066094-45a8-4c68-b307-86195e2c1103
232 ;;; parse-time.el ends here