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