;;; time-date.el --- Date and time handling functions
-;; Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+
+;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
+;; 2007, 2008 Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Masanobu Umeda <umerin@mse.kyutech.ac.jp>
;; This file is part of GNU Emacs.
-;; GNU Emacs is free software; you can redistribute it and/or modify
+;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation; either version 2, or (at your option)
-;; any later version.
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
+;; Time values come in three formats. The oldest format is a cons
+;; cell of the form (HIGH . LOW). This format is obsolete, but still
+;; supported. The two other formats are the lists (HIGH LOW) and
+;; (HIGH LOW MICRO). The first two formats specify HIGH * 2^16 + LOW
+;; seconds; the third format specifies HIGH * 2^16 + LOW + MICRO /
+;; 1000000 seconds. We should have 0 <= MICRO < 1000000 and 0 <= LOW
+;; < 2^16. If the time value represents a point in time, then HIGH is
+;; nonnegative. If the time value is a time difference, then HIGH can
+;; be negative as well. The macro `with-decoded-time-value' and the
+;; function `encode-time-value' make it easier to deal with these
+;; three formats. See `time-subtract' for an example of how to use
+;; them.
+
;;; Code:
-(require 'parse-time)
+(defmacro with-decoded-time-value (varlist &rest body)
+ "Decode a time value and bind it according to VARLIST, then eval BODY.
+
+The value of the last form in BODY is returned.
+
+Each element of the list VARLIST is a list of the form
+\(HIGH-SYMBOL LOW-SYMBOL MICRO-SYMBOL [TYPE-SYMBOL] TIME-VALUE).
+The time value TIME-VALUE is decoded and the result it bound to
+the symbols HIGH-SYMBOL, LOW-SYMBOL and MICRO-SYMBOL.
+The optional TYPE-SYMBOL is bound to the type of the time value.
+Type 0 is the cons cell (HIGH . LOW), type 1 is the list (HIGH
+LOW), and type 2 is the list (HIGH LOW MICRO)."
+ (declare (indent 1)
+ (debug ((&rest (symbolp symbolp symbolp &or [symbolp form] form))
+ body)))
+ (if varlist
+ (let* ((elt (pop varlist))
+ (high (pop elt))
+ (low (pop elt))
+ (micro (pop elt))
+ (type (unless (eq (length elt) 1)
+ (pop elt)))
+ (time-value (car elt))
+ (gensym (make-symbol "time")))
+ `(let* ,(append `((,gensym ,time-value)
+ (,high (pop ,gensym))
+ ,low ,micro)
+ (when type `(,type)))
+ (if (consp ,gensym)
+ (progn
+ (setq ,low (pop ,gensym))
+ (if ,gensym
+ ,(append `(setq ,micro (car ,gensym))
+ (when type `(,type 2)))
+ ,(append `(setq ,micro 0)
+ (when type `(,type 1)))))
+ ,(append `(setq ,low ,gensym ,micro 0)
+ (when type `(,type 0))))
+ (with-decoded-time-value ,varlist ,@body)))
+ `(progn ,@body)))
+
+(defun encode-time-value (high low micro type)
+ "Encode HIGH, LOW, and MICRO into a time value of type TYPE.
+Type 0 is the cons cell (HIGH . LOW), type 1 is the list (HIGH LOW),
+and type 2 is the list (HIGH LOW MICRO)."
+ (cond
+ ((eq type 0) (cons high low))
+ ((eq type 1) (list high low))
+ ((eq type 2) (list high low micro))))
+
+(autoload 'parse-time-string "parse-time")
(autoload 'timezone-make-date-arpa-standard "timezone")
;;;###autoload
(defun date-to-time (date)
- "Parse a string that represents a date-time and return a time value."
+ "Parse a string DATE that represents a date-time and return a time value."
(condition-case ()
(apply 'encode-time
(parse-time-string
(timezone-make-date-arpa-standard date)))
(error (error "Invalid date: %s" date))))
+;;;###autoload
(defun time-to-seconds (time)
"Convert time value TIME to a floating point number.
You can use `float-time' instead."
- (+ (* (car time) 65536.0)
- (cadr time)
- (/ (or (nth 2 time) 0) 1000000.0)))
+ (with-decoded-time-value ((high low micro time))
+ (+ (* 1.0 high 65536)
+ low
+ (/ micro 1000000.0))))
;;;###autoload
(defun seconds-to-time (seconds)
;;;###autoload
(defun time-less-p (t1 t2)
"Say whether time value T1 is less than time value T2."
- (or (< (car t1) (car t2))
- (and (= (car t1) (car t2))
- (< (nth 1 t1) (nth 1 t2)))))
+ (with-decoded-time-value ((high1 low1 micro1 t1)
+ (high2 low2 micro2 t2))
+ (or (< high1 high2)
+ (and (= high1 high2)
+ (or (< low1 low2)
+ (and (= low1 low2)
+ (< micro1 micro2)))))))
;;;###autoload
(defun days-to-time (days)
"Convert DAYS into a time value."
(let* ((seconds (* 1.0 days 60 60 24))
- (rest (expt 2 16))
- (ms (condition-case nil (floor (/ seconds rest))
- (range-error (expt 2 16)))))
- (list ms (condition-case nil (round (- seconds (* ms rest)))
- (range-error (expt 2 16))))))
+ (high (condition-case nil (floor (/ seconds 65536))
+ (range-error most-positive-fixnum))))
+ (list high (condition-case nil (floor (- seconds (* 1.0 high 65536)))
+ (range-error 65535)))))
;;;###autoload
(defun time-since (time)
(when (stringp time)
;; Convert date strings to internal time.
(setq time (date-to-time time)))
- (let* ((current (current-time))
- (rest (when (< (nth 1 current) (nth 1 time))
- (expt 2 16))))
- (list (- (+ (car current) (if rest -1 0)) (car time))
- (- (+ (or rest 0) (nth 1 current)) (nth 1 time)))))
+ (time-subtract (current-time) time))
;;;###autoload
(defalias 'subtract-time 'time-subtract)
;;;###autoload
(defun time-subtract (t1 t2)
- "Subtract two time values.
+ "Subtract two time values, T1 minus T2.
Return the difference in the format of a time value."
- (let ((borrow (< (cadr t1) (cadr t2))))
- (list (- (car t1) (car t2) (if borrow 1 0))
- (- (+ (if borrow 65536 0) (cadr t1)) (cadr t2)))))
+ (with-decoded-time-value ((high low micro type t1)
+ (high2 low2 micro2 type2 t2))
+ (setq high (- high high2)
+ low (- low low2)
+ micro (- micro micro2)
+ type (max type type2))
+ (when (< micro 0)
+ (setq low (1- low)
+ micro (+ micro 1000000)))
+ (when (< low 0)
+ (setq high (1- high)
+ low (+ low 65536)))
+ (encode-time-value high low micro type)))
;;;###autoload
(defun time-add (t1 t2)
- "Add two time values. One should represent a time difference."
- (let ((high (car t1))
- (low (if (consp (cdr t1)) (nth 1 t1) (cdr t1)))
- (micro (if (numberp (car-safe (cdr-safe (cdr t1))))
- (nth 2 t1)
- 0))
- (high2 (car t2))
- (low2 (if (consp (cdr t2)) (nth 1 t2) (cdr t2)))
- (micro2 (if (numberp (car-safe (cdr-safe (cdr t2))))
- (nth 2 t2)
- 0)))
- ;; Add
- (setq micro (+ micro micro2))
- (setq low (+ low low2))
- (setq high (+ high high2))
-
- ;; Normalize
- ;; `/' rounds towards zero while `mod' returns a positive number,
- ;; so we can't rely on (= a (+ (* 100 (/ a 100)) (mod a 100))).
- (setq low (+ low (/ micro 1000000) (if (< micro 0) -1 0)))
- (setq micro (mod micro 1000000))
- (setq high (+ high (/ low 65536) (if (< low 0) -1 0)))
- (setq low (logand low 65535))
-
- (list high low micro)))
+ "Add two time values T1 and T2. One should represent a time difference."
+ (with-decoded-time-value ((high low micro type t1)
+ (high2 low2 micro2 type2 t2))
+ (setq high (+ high high2)
+ low (+ low low2)
+ micro (+ micro micro2)
+ type (max type type2))
+ (when (>= micro 1000000)
+ (setq low (1+ low)
+ micro (- micro 1000000)))
+ (when (>= low 65536)
+ (setq high (1+ high)
+ low (- low 65536)))
+ (encode-time-value high low micro type)))
;;;###autoload
(defun date-to-day (date)
;;;###autoload
(defun time-to-day-in-year (time)
- "Return the day number within the year of the date month/day/year."
+ "Return the day number within the year corresponding to TIME."
(let* ((tim (decode-time time))
(month (nth 4 tim))
(day (nth 3 tim))
(defun time-to-number-of-days (time)
"Return the number of days represented by TIME.
The number of days will be returned as a floating point number."
- (/ (+ (* 1.0 65536 (car time)) (cadr time)) (* 60 60 24)))
+ (/ (time-to-seconds time) (* 60 60 24)))
;;;###autoload
(defun safe-date-to-time (date)
- "Parse a string that represents a date-time and return a time value.
+ "Parse a string DATE that represents a date-time and return a time value.
If DATE is malformed, return a time value of zeros."
(condition-case ()
(date-to-time date)
(error '(0 0))))
+\f
+;;;###autoload
+(defun format-seconds (string seconds)
+ "Use format control STRING to format the number SECONDS.
+The valid format specifiers are:
+%y is the number of (365-day) years.
+%d is the number of days.
+%h is the number of hours.
+%m is the number of minutes.
+%s is the number of seconds.
+%z is a non-printing control flag (see below).
+%% is a literal \"%\".
+
+Upper-case specifiers are followed by the unit-name (e.g. \"years\").
+Lower-case specifiers return only the unit.
+
+\"%\" may be followed by a number specifying a width, with an
+optional leading \".\" for zero-padding. For example, \"%.3Y\" will
+return something of the form \"001 year\".
+
+The \"%z\" specifier does not print anything. When it is used, specifiers
+must be given in order of decreasing size. To the left of \"%z\", nothing
+is output until the first non-zero unit is encountered.
+
+This function does not work for SECONDS greater than `most-positive-fixnum'."
+ (let ((start 0)
+ (units '(("y" "year" 31536000)
+ ("d" "day" 86400)
+ ("h" "hour" 3600)
+ ("m" "minute" 60)
+ ("s" "second" 1)
+ ("z")))
+ (case-fold-search t)
+ spec match usedunits zeroflag larger prev name unit num zeropos)
+ (while (string-match "%\\.?[0-9]*\\(.\\)" string start)
+ (setq start (match-end 0)
+ spec (match-string 1 string))
+ (unless (string-equal spec "%")
+ (or (setq match (assoc-string spec units t))
+ (error "Bad format specifier: `%s'" spec))
+ (if (assoc-string spec usedunits t)
+ (error "Multiple instances of specifier: `%s'" spec))
+ (if (string-equal (car match) "z")
+ (setq zeroflag t)
+ (unless larger
+ (setq unit (nth 2 match)
+ larger (and prev (> unit prev))
+ prev unit)))
+ (push match usedunits)))
+ (and zeroflag larger
+ (error "Units are not in decreasing order of size"))
+ (dolist (u units)
+ (setq spec (car u)
+ name (cadr u)
+ unit (nth 2 u))
+ (when (string-match (format "%%\\(\\.?[0-9]+\\)?\\(%s\\)" spec) string)
+ (if (string-equal spec "z") ; must be last in units
+ (setq string
+ (replace-regexp-in-string
+ "%z" ""
+ (substring string (min (or zeropos (match-end 0))
+ (match-beginning 0)))))
+ ;; Cf article-make-date-line in gnus-art.
+ (setq num (floor seconds unit)
+ seconds (- seconds (* num unit)))
+ ;; Start position of the first non-zero unit.
+ (or zeropos
+ (setq zeropos (unless (zerop num) (match-beginning 0))))
+ (setq string
+ (replace-match
+ (format (concat "%" (match-string 1 string) "d%s") num
+ (if (string-equal (match-string 2 string) spec)
+ "" ; lower-case, no unit-name
+ (format " %s%s" name
+ (if (= num 1) "" "s"))))
+ t t string))))))
+ (replace-regexp-in-string "%%" "%" string))
+
+
(provide 'time-date)
-;;; arch-tag: addcf07b-b20a-465b-af72-550b8ac5190f
+;; arch-tag: addcf07b-b20a-465b-af72-550b8ac5190f
;;; time-date.el ends here