1 ;;; parse-time.el --- parsing time strings
3 ;; Copyright (C) 1996, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
4 ;; 2008, 2009, 2010 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
41 (when (featurep 'xemacs)
42 (defvar parse-time-syntax (make-vector 256 nil))))
43 (defvar parse-time-digits (make-vector 256 nil))
45 ;; Byte-compiler warnings
46 (defvar parse-time-elt)
47 (defvar parse-time-val)
49 (unless (aref parse-time-digits ?0)
50 (loop for i from ?0 to ?9
51 do (aset parse-time-digits i (- i ?0))))
53 (when (featurep 'xemacs)
54 (unless (aref parse-time-syntax ?0)
55 (loop for i from ?0 to ?9
56 do (aset parse-time-syntax i ?0))
57 (loop for i from ?A to ?Z
58 do (aset parse-time-syntax i ?A))
59 (loop for i from ?a to ?z
60 do (aset parse-time-syntax i ?a))
61 (aset parse-time-syntax ?+ 1)
62 (aset parse-time-syntax ?- -1)
63 (aset parse-time-syntax ?: ?d)))
65 (defsubst digit-char-p (char)
66 (aref parse-time-digits char))
69 (if (featurep 'xemacs)
70 (defsubst parse-time-string-chars (char)
71 (and (< char (length parse-time-syntax))
72 (aref parse-time-syntax char)))
73 (defsubst parse-time-string-chars (char)
75 (let (case-fold-search str)
76 (cond ((eq char ?+) 1)
79 ((string-match "[[:upper:]]" (setq str (string char))) ?A)
80 ((string-match "[[:lower:]]" str) ?a)
81 ((string-match "[[:digit:]]" str) ?0)))))))
83 (put 'parse-error 'error-conditions '(parse-error error))
84 (put 'parse-error 'error-message "Parsing error")
86 (defsubst parse-integer (string &optional start end)
87 "[CL] Parse and return the integer in STRING, or nil if none."
91 (end (or end (length string))))
93 (let ((sign (aref string index)))
94 (if (or (eq sign ?+) (eq sign ?-))
95 (setq sign (parse-time-string-chars sign)
98 (while (and (< index end)
99 (setq digit (digit-char-p (aref string index))))
100 (setq integer (+ (* integer 10) digit)
103 (signal 'parse-error `("not an integer"
104 ,(substring string (or start 0) end)))
105 (* sign integer))))))
107 (defun parse-time-tokenize (string)
108 "Tokenize STRING into substrings."
110 (end (length string))
116 (while (and (< index end) ;skip invalid characters
117 (not (setq c (parse-time-string-chars (aref string index)))))
119 (setq start index all-digits (eq c ?0))
120 (while (and (< (incf index) end) ;scan valid characters
121 (setq c (parse-time-string-chars (aref string index))))
122 (setq all-digits (and all-digits (eq c ?0))))
124 (push (if all-digits (parse-integer string start index)
125 (substring string start index))
129 (defvar parse-time-months '(("jan" . 1) ("feb" . 2) ("mar" . 3)
130 ("apr" . 4) ("may" . 5) ("jun" . 6)
131 ("jul" . 7) ("aug" . 8) ("sep" . 9)
132 ("oct" . 10) ("nov" . 11) ("dec" . 12)
133 ("january" . 1) ("february" . 2)
134 ("march" . 3) ("april" . 4) ("june" . 6)
135 ("july" . 7) ("august" . 8)
136 ("september" . 9) ("october" . 10)
137 ("november" . 11) ("december" . 12)))
138 (defvar parse-time-weekdays '(("sun" . 0) ("mon" . 1) ("tue" . 2)
139 ("wed" . 3) ("thu" . 4) ("fri" . 5)
140 ("sat" . 6) ("sunday" . 0) ("monday" . 1)
141 ("tuesday" . 2) ("wednesday" . 3)
142 ("thursday" . 4) ("friday" . 5)
144 (defvar parse-time-zoneinfo `(("z" 0) ("ut" 0) ("gmt" 0)
145 ("pst" ,(* -8 3600)) ("pdt" ,(* -7 3600) t)
146 ("mst" ,(* -7 3600)) ("mdt" ,(* -6 3600) t)
147 ("cst" ,(* -6 3600)) ("cdt" ,(* -5 3600) t)
148 ("est" ,(* -5 3600)) ("edt" ,(* -4 3600) t))
149 "(zoneinfo seconds-off daylight-savings-time-p)")
151 (defvar parse-time-rules
152 `(((6) parse-time-weekdays)
154 ((4) parse-time-months)
157 ,#'(lambda () (and (stringp parse-time-elt)
158 (= (length parse-time-elt) 8)
159 (= (aref parse-time-elt 2) ?:)
160 (= (aref parse-time-elt 5) ?:)))
162 ((8 7) parse-time-zoneinfo
163 ,#'(lambda () (car parse-time-val))
164 ,#'(lambda () (cadr parse-time-val)))
167 (and (stringp parse-time-elt)
168 (= 5 (length parse-time-elt))
169 (or (= (aref parse-time-elt 0) ?+)
170 (= (aref parse-time-elt 0) ?-))))
171 ,#'(lambda () (* 60 (+ (parse-integer parse-time-elt 3 5)
172 (* 60 (parse-integer parse-time-elt 1 3)))
173 (if (= (aref parse-time-elt 0) ?-) -1 1))))
175 ,#'(lambda () (and (stringp parse-time-elt)
176 (= (length parse-time-elt) 10)
177 (= (aref parse-time-elt 4) ?-)
178 (= (aref parse-time-elt 7) ?-)))
181 ,#'(lambda () (and (stringp parse-time-elt)
182 (= (length parse-time-elt) 5)
183 (= (aref parse-time-elt 2) ?:)))
184 [0 2] [3 5] ,#'(lambda () 0))
186 ,#'(lambda () (and (stringp parse-time-elt)
187 (= (length parse-time-elt) 4)
188 (= (aref parse-time-elt 1) ?:)))
189 [0 1] [2 4] ,#'(lambda () 0))
191 ,#'(lambda () (and (stringp parse-time-elt)
192 (= (length parse-time-elt) 7)
193 (= (aref parse-time-elt 1) ?:)))
195 ((5) (50 110) ,#'(lambda () (+ 1900 parse-time-elt)))
196 ((5) (0 49) ,#'(lambda () (+ 2000 parse-time-elt))))
197 "(slots predicate extractor...)")
198 ;;;###autoload(put 'parse-time-rules 'risky-local-variable t)
201 (defun parse-time-string (string)
202 "Parse the time-string STRING into (SEC MIN HOUR DAY MON YEAR DOW DST TZ).
203 The values are identical to those of `decode-time', but any values that are
204 unknown are returned as nil."
205 (let ((time (list nil nil nil nil nil nil nil nil nil))
206 (temp (parse-time-tokenize (downcase string))))
208 (let ((parse-time-elt (pop temp))
209 (rules parse-time-rules)
211 (while (and rules (not exit))
212 (let* ((rule (pop rules))
214 (predicate (pop rule))
216 (when (and (not (nth (car slots) time)) ;not already set
217 (setq parse-time-val (cond ((and (consp predicate)
218 (not (eq (car predicate)
220 (and (numberp parse-time-elt)
221 (<= (car predicate) parse-time-elt)
222 (<= parse-time-elt (cadr predicate))
225 (cdr (assoc parse-time-elt
226 (symbol-value predicate))))
227 ((funcall predicate)))))
230 (let ((new-val (and rule
231 (let ((this (pop rule)))
235 (aref this 0) (aref this 1))
237 (rplaca (nthcdr (pop slots) time)
238 (or new-val parse-time-val)))))))))
241 (provide 'parse-time)
243 ;; arch-tag: 07066094-45a8-4c68-b307-86195e2c1103
244 ;;; parse-time.el ends here