1 ;;; parse-time.el --- parsing time strings
3 ;; Copyright (C) 1996, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
4 ;; 2008 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)
63 (defsubst digit-char-p (char)
64 (aref parse-time-digits char))
66 (defsubst parse-time-string-chars (char)
67 (and (< char (length parse-time-syntax))
68 (aref parse-time-syntax char)))
70 (put 'parse-error 'error-conditions '(parse-error error))
71 (put 'parse-error 'error-message "Parsing error")
73 (defsubst parse-integer (string &optional start end)
74 "[CL] Parse and return the integer in STRING, or nil if none."
78 (end (or end (length string))))
80 (let ((sign (aref string index)))
81 (if (or (eq sign ?+) (eq sign ?-))
82 (setq sign (parse-time-string-chars sign)
85 (while (and (< index end)
86 (setq digit (digit-char-p (aref string index))))
87 (setq integer (+ (* integer 10) digit)
90 (signal 'parse-error `("not an integer"
91 ,(substring string (or start 0) end)))
94 (defun parse-time-tokenize (string)
95 "Tokenize STRING into substrings."
103 (while (and (< index end) ;skip invalid characters
104 (not (setq c (parse-time-string-chars (aref string index)))))
106 (setq start index all-digits (eq c ?0))
107 (while (and (< (incf index) end) ;scan valid characters
108 (setq c (parse-time-string-chars (aref string index))))
109 (setq all-digits (and all-digits (eq c ?0))))
111 (push (if all-digits (parse-integer string start index)
112 (substring string start index))
116 (defvar parse-time-months '(("jan" . 1) ("feb" . 2) ("mar" . 3)
117 ("apr" . 4) ("may" . 5) ("jun" . 6)
118 ("jul" . 7) ("aug" . 8) ("sep" . 9)
119 ("oct" . 10) ("nov" . 11) ("dec" . 12)))
120 (defvar parse-time-weekdays '(("sun" . 0) ("mon" . 1) ("tue" . 2)
121 ("wed" . 3) ("thu" . 4) ("fri" . 5) ("sat" . 6)))
122 (defvar parse-time-zoneinfo `(("z" 0) ("ut" 0) ("gmt" 0)
123 ("pst" ,(* -8 3600)) ("pdt" ,(* -7 3600) t)
124 ("mst" ,(* -7 3600)) ("mdt" ,(* -6 3600) t)
125 ("cst" ,(* -6 3600)) ("cdt" ,(* -5 3600) t)
126 ("est" ,(* -5 3600)) ("edt" ,(* -4 3600) t))
127 "(zoneinfo seconds-off daylight-savings-time-p)")
129 (defvar parse-time-rules
130 `(((6) parse-time-weekdays)
132 ((4) parse-time-months)
135 ,#'(lambda () (and (stringp parse-time-elt)
136 (= (length parse-time-elt) 8)
137 (= (aref parse-time-elt 2) ?:)
138 (= (aref parse-time-elt 5) ?:)))
140 ((8 7) parse-time-zoneinfo
141 ,#'(lambda () (car parse-time-val))
142 ,#'(lambda () (cadr parse-time-val)))
145 (and (stringp parse-time-elt)
146 (= 5 (length parse-time-elt))
147 (or (= (aref parse-time-elt 0) ?+)
148 (= (aref parse-time-elt 0) ?-))))
149 ,#'(lambda () (* 60 (+ (parse-integer parse-time-elt 3 5)
150 (* 60 (parse-integer parse-time-elt 1 3)))
151 (if (= (aref parse-time-elt 0) ?-) -1 1))))
153 ,#'(lambda () (and (stringp parse-time-elt)
154 (= (length parse-time-elt) 10)
155 (= (aref parse-time-elt 4) ?-)
156 (= (aref parse-time-elt 7) ?-)))
159 ,#'(lambda () (and (stringp parse-time-elt)
160 (= (length parse-time-elt) 5)
161 (= (aref parse-time-elt 2) ?:)))
162 [0 2] [3 5] ,#'(lambda () 0))
164 ,#'(lambda () (and (stringp parse-time-elt)
165 (= (length parse-time-elt) 4)
166 (= (aref parse-time-elt 1) ?:)))
167 [0 1] [2 4] ,#'(lambda () 0))
169 ,#'(lambda () (and (stringp parse-time-elt)
170 (= (length parse-time-elt) 7)
171 (= (aref parse-time-elt 1) ?:)))
173 ((5) (50 110) ,#'(lambda () (+ 1900 parse-time-elt)))
174 ((5) (0 49) ,#'(lambda () (+ 2000 parse-time-elt))))
175 "(slots predicate extractor...)")
178 (defun parse-time-string (string)
179 "Parse the time-string STRING into (SEC MIN HOUR DAY MON YEAR DOW DST TZ).
180 The values are identical to those of `decode-time', but any values that are
181 unknown are returned as nil."
182 (let ((time (list nil nil nil nil nil nil nil nil nil))
183 (temp (parse-time-tokenize (downcase string))))
185 (let ((parse-time-elt (pop temp))
186 (rules parse-time-rules)
188 (while (and rules (not exit))
189 (let* ((rule (pop rules))
191 (predicate (pop rule))
193 (when (and (not (nth (car slots) time)) ;not already set
194 (setq parse-time-val (cond ((and (consp predicate)
195 (not (eq (car predicate)
197 (and (numberp parse-time-elt)
198 (<= (car predicate) parse-time-elt)
199 (<= parse-time-elt (cadr predicate))
202 (cdr (assoc parse-time-elt
203 (symbol-value predicate))))
204 ((funcall predicate)))))
207 (let ((new-val (and rule
208 (let ((this (pop rule)))
212 (aref this 0) (aref this 1))
214 (rplaca (nthcdr (pop slots) time)
215 (or new-val parse-time-val)))))))))
218 (provide 'parse-time)
220 ;; arch-tag: 07066094-45a8-4c68-b307-86195e2c1103
221 ;;; parse-time.el ends here