1 ;;; parse-time.el --- parsing time strings
3 ;; Copyright (C) 1996, 2000-2013 Free Software Foundation, Inc.
5 ;; Author: Erik Naggum <erik@naggum.no>
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software: you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation, either version 3 of the License, or
13 ;; (at your option) any later version.
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
25 ;; With the introduction of the `encode-time', `decode-time', and
26 ;; `format-time-string' functions, dealing with time became simpler in
27 ;; Emacs. However, parsing time strings is still largely a matter of
28 ;; heuristics and no common interface has been designed.
30 ;; `parse-time-string' parses a time in a string and returns a list of 9
31 ;; values, just like `decode-time', where unspecified elements in the
32 ;; string are returned as nil. `encode-time' may be applied on these
33 ;; values to obtain an internal time value.
37 (eval-when-compile (require 'cl)) ;and ah ain't kiddin' 'bout it
40 (when (featurep 'xemacs)
41 (defvar parse-time-syntax (make-vector 256 nil))))
42 (defvar parse-time-digits (make-vector 256 nil))
44 ;; Byte-compiler warnings
45 (defvar parse-time-elt)
46 (defvar parse-time-val)
48 (unless (aref parse-time-digits ?0)
49 (loop for i from ?0 to ?9
50 do (aset parse-time-digits i (- i ?0))))
52 (when (featurep 'xemacs)
53 (unless (aref parse-time-syntax ?0)
54 (loop for i from ?0 to ?9
55 do (aset parse-time-syntax i ?0))
56 (loop for i from ?A to ?Z
57 do (aset parse-time-syntax i ?A))
58 (loop for i from ?a to ?z
59 do (aset parse-time-syntax i ?a))
60 (aset parse-time-syntax ?+ 1)
61 (aset parse-time-syntax ?- -1)
62 (aset parse-time-syntax ?: ?d)))
64 (defsubst digit-char-p (char)
65 (aref parse-time-digits char))
68 (if (featurep 'xemacs)
69 (defsubst parse-time-string-chars (char)
70 (and (< char (length parse-time-syntax))
71 (aref parse-time-syntax char)))
72 (defsubst parse-time-string-chars (char)
74 (let (case-fold-search str)
75 (cond ((eq char ?+) 1)
78 ((string-match "[[:upper:]]" (setq str (string char))) ?A)
79 ((string-match "[[:lower:]]" str) ?a)
80 ((string-match "[[:digit:]]" str) ?0)))))))
82 (put 'parse-error 'error-conditions '(parse-error error))
83 (put 'parse-error 'error-message "Parsing error")
85 (defsubst parse-integer (string &optional start end)
86 "[CL] Parse and return the integer in STRING, or nil if none."
90 (end (or end (length string))))
92 (let ((sign (aref string index)))
93 (if (or (eq sign ?+) (eq sign ?-))
94 (setq sign (parse-time-string-chars sign)
97 (while (and (< index end)
98 (setq digit (digit-char-p (aref string index))))
99 (setq integer (+ (* integer 10) digit)
102 (signal 'parse-error `("not an integer"
103 ,(substring string (or start 0) end)))
104 (* sign integer))))))
106 (defun parse-time-tokenize (string)
107 "Tokenize STRING into substrings."
109 (end (length string))
115 (while (and (< index end) ;Skip invalid characters.
116 (not (setq c (parse-time-string-chars (aref string index)))))
118 (setq start index all-digits (eq c ?0))
119 (while (and (< (incf index) end) ;Scan valid characters.
120 (setq c (parse-time-string-chars (aref string index))))
121 (setq all-digits (and all-digits (eq c ?0))))
123 (push (if all-digits (parse-integer string start index)
124 (substring string start index))
128 (defvar parse-time-months '(("jan" . 1) ("feb" . 2) ("mar" . 3)
129 ("apr" . 4) ("may" . 5) ("jun" . 6)
130 ("jul" . 7) ("aug" . 8) ("sep" . 9)
131 ("oct" . 10) ("nov" . 11) ("dec" . 12)
132 ("january" . 1) ("february" . 2)
133 ("march" . 3) ("april" . 4) ("june" . 6)
134 ("july" . 7) ("august" . 8)
135 ("september" . 9) ("october" . 10)
136 ("november" . 11) ("december" . 12)))
137 (defvar parse-time-weekdays '(("sun" . 0) ("mon" . 1) ("tue" . 2)
138 ("wed" . 3) ("thu" . 4) ("fri" . 5)
139 ("sat" . 6) ("sunday" . 0) ("monday" . 1)
140 ("tuesday" . 2) ("wednesday" . 3)
141 ("thursday" . 4) ("friday" . 5)
143 (defvar parse-time-zoneinfo `(("z" 0) ("ut" 0) ("gmt" 0)
144 ("pst" ,(* -8 3600)) ("pdt" ,(* -7 3600) t)
145 ("mst" ,(* -7 3600)) ("mdt" ,(* -6 3600) t)
146 ("cst" ,(* -6 3600)) ("cdt" ,(* -5 3600) t)
147 ("est" ,(* -5 3600)) ("edt" ,(* -4 3600) t))
148 "(zoneinfo seconds-off daylight-savings-time-p)")
150 (defvar parse-time-rules
151 `(((6) parse-time-weekdays)
153 ((4) parse-time-months)
156 ,#'(lambda () (and (stringp parse-time-elt)
157 (= (length parse-time-elt) 8)
158 (= (aref parse-time-elt 2) ?:)
159 (= (aref parse-time-elt 5) ?:)))
161 ((8 7) parse-time-zoneinfo
162 ,#'(lambda () (car parse-time-val))
163 ,#'(lambda () (cadr parse-time-val)))
166 (and (stringp parse-time-elt)
167 (= 5 (length parse-time-elt))
168 (or (= (aref parse-time-elt 0) ?+)
169 (= (aref parse-time-elt 0) ?-))))
170 ,#'(lambda () (* 60 (+ (parse-integer parse-time-elt 3 5)
171 (* 60 (parse-integer parse-time-elt 1 3)))
172 (if (= (aref parse-time-elt 0) ?-) -1 1))))
174 ,#'(lambda () (and (stringp parse-time-elt)
175 (= (length parse-time-elt) 10)
176 (= (aref parse-time-elt 4) ?-)
177 (= (aref parse-time-elt 7) ?-)))
180 ,#'(lambda () (and (stringp parse-time-elt)
181 (= (length parse-time-elt) 5)
182 (= (aref parse-time-elt 2) ?:)))
183 [0 2] [3 5] ,#'(lambda () 0))
185 ,#'(lambda () (and (stringp parse-time-elt)
186 (= (length parse-time-elt) 4)
187 (= (aref parse-time-elt 1) ?:)))
188 [0 1] [2 4] ,#'(lambda () 0))
190 ,#'(lambda () (and (stringp parse-time-elt)
191 (= (length parse-time-elt) 7)
192 (= (aref parse-time-elt 1) ?:)))
194 ((5) (50 110) ,#'(lambda () (+ 1900 parse-time-elt)))
195 ((5) (0 49) ,#'(lambda () (+ 2000 parse-time-elt))))
196 "(slots predicate extractor...)")
197 ;;;###autoload(put 'parse-time-rules 'risky-local-variable t)
200 (defun parse-time-string (string)
201 "Parse the time-string STRING into (SEC MIN HOUR DAY MON YEAR DOW DST TZ).
202 The values are identical to those of `decode-time', but any values that are
203 unknown are returned as nil."
204 (let ((time (list nil nil nil nil nil nil nil nil nil))
205 (temp (parse-time-tokenize (downcase string))))
207 (let ((parse-time-elt (pop temp))
208 (rules parse-time-rules)
210 (while (and rules (not exit))
211 (let* ((rule (pop rules))
213 (predicate (pop rule))
215 (when (and (not (nth (car slots) time)) ;not already set
217 (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 (if rule
231 (let ((this (pop rule)))
235 (aref this 0) (aref this 1))
238 (rplaca (nthcdr (pop slots) time) new-val))))))))
241 (provide 'parse-time)
243 ;;; parse-time.el ends here