* Re: The format of time values in lisp/calendar/time-date.el.
2005-03-14 23:43 ` Richard Stallman
@ 2005-03-16 17:01 ` Lute Kamstra
0 siblings, 0 replies; 3+ messages in thread
From: Lute Kamstra @ 2005-03-16 17:01 UTC (permalink / raw)
Cc: emacs-devel
Richard Stallman <rms@gnu.org> writes:
> Was there an evolution in format from (HIGH . LOW), via (HIGH LOW), to
> (HIGH LOW MICRO)?
>
> Yes. Both (HIGH LOW) and (HIGH LOW MICRO) are valid now.
> It is useful to accept (HIGH . LOW) as well.
>
> Shall I fix time-less-p and time-subtract to deal with (HIGH LOW
> MICRO) arguments as well?
>
> Yes, please do.
>
> Should they deal with (HIGH . LOW) too?
>
> It would not be a bad thing.
>
> What about the return value of time-subtract (and time-add): should it
> be backward compatible in the sense that it returns (HIGH LOW) if both
> its arguments are of that format?
>
> Yes.
Done. Any objections to this patch?
Lute.
Index: lisp/ChangeLog
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/ChangeLog,v
retrieving revision 1.7106
diff -c -r1.7106 ChangeLog
*** lisp/ChangeLog 16 Mar 2005 13:21:20 -0000 1.7106
--- lisp/ChangeLog 16 Mar 2005 16:54:07 -0000
***************
*** 1,3 ****
--- 1,12 ----
+ 2005-03-16 Lute Kamstra <lute@gnu.org>
+
+ * calendar/time-date.el: Add comment on time value formats. Don't
+ require parse-time.
+ (time-to-seconds, time-less-p, time-since, time-subtract)
+ (time-add, time-to-number-of-days): Deal with all three formats of
+ time values.
+ (days-to-time): Return a valid time value when arg is huge.
+
2005-03-16 Glenn Morris <gmorris@ast.cam.ac.uk>
* calendar/diary-lib.el (mark-diary-entries): Use new optional
Index: lisp/calendar/time-date.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/calendar/time-date.el,v
retrieving revision 1.9
diff -c -r1.9 time-date.el
*** lisp/calendar/time-date.el 4 Sep 2004 13:13:48 -0000 1.9
--- lisp/calendar/time-date.el 16 Mar 2005 16:51:28 -0000
***************
*** 1,5 ****
;;; time-date.el --- date and time handling functions
! ;; Copyright (C) 1998, 1999, 2000, 2004 Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Masanobu Umeda <umerin@mse.kyutech.ac.jp>
--- 1,5 ----
;;; time-date.el --- date and time handling functions
! ;; Copyright (C) 1998, 1999, 2000, 2004, 2005 Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Masanobu Umeda <umerin@mse.kyutech.ac.jp>
***************
*** 24,32 ****
;;; Commentary:
! ;;; Code:
! (require 'parse-time)
(autoload 'timezone-make-date-arpa-standard "timezone")
--- 24,41 ----
;;; 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. See `time-subtract' for an example of how to
! ;; deal with these three formats.
! ;;; Code:
(autoload 'timezone-make-date-arpa-standard "timezone")
***************
*** 49,81 ****
(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)))
;;;###autoload
(defun seconds-to-time (seconds)
"Convert SECONDS (a floating point number) to a time value."
! (list (floor seconds 65536)
! (floor (mod seconds 65536))
(floor (* (- seconds (ffloor seconds)) 1000000))))
;;;###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)))))
;;;###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))))))
;;;###autoload
(defun time-since (time)
--- 58,104 ----
(defun time-to-seconds (time)
"Convert time value TIME to a floating point number.
You can use `float-time' instead."
! (+ (* 1.0 (pop time) #x10000)
! (if (consp time) (pop time) time)
! (/ (if (numberp (car-safe time))
! (car time)
! 0)
! 1000000.0)))
;;;###autoload
(defun seconds-to-time (seconds)
"Convert SECONDS (a floating point number) to a time value."
! (list (floor seconds #x10000)
! (floor (mod seconds #x10000))
(floor (* (- seconds (ffloor seconds)) 1000000))))
;;;###autoload
(defun time-less-p (t1 t2)
"Say whether time value T1 is less than time value T2."
! (let* ((high1 (pop t1))
! (low1 (if (consp t1) (pop t1) t1))
! (micro1 (if (numberp (car-safe t1))
! (car t1)
! 0))
! (high2 (pop t2))
! (low2 (if (consp t2) (pop t2) t2))
! (micro2 (if (numberp (car-safe t2))
! (car t2)
! 0)))
! (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))
! (high (condition-case nil (floor (/ seconds #x10000))
! (range-error most-positive-fixnum))))
! (list high (condition-case nil (floor (- seconds (* 1.0 high #x10000)))
! (range-error #xffff)))))
;;;###autoload
(defun time-since (time)
***************
*** 84,94 ****
(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)))))
;;;###autoload
(defalias 'subtract-time 'time-subtract)
--- 107,113 ----
(when (stringp time)
;; Convert date strings to internal time.
(setq time (date-to-time time)))
! (time-subtract (current-time) time))
;;;###autoload
(defalias 'subtract-time 'time-subtract)
***************
*** 97,133 ****
(defun time-subtract (t1 t2)
"Subtract two time values.
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)))))
;;;###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)))
;;;###autoload
(defun date-to-day (date)
--- 116,169 ----
(defun time-subtract (t1 t2)
"Subtract two time values.
Return the difference in the format of a time value."
! (let* ((high (- (pop t1) (pop t2)))
! (low (- (if (consp t1) (pop t1) t1)
! (if (consp t2) (pop t2) t2)))
! (micro (- (if (numberp (car-safe t1))
! (car t1)
! 0)
! (if (numberp (car-safe t2))
! (car t2)
! 0))))
! (when (< micro 0)
! (setq low (1- low)
! micro (+ micro 1000000)))
! (when (< low 0)
! (setq high (1- high)
! low (+ low #x10000)))
! (cons high
! (if (or (consp t1) (consp t2))
! (cons low
! (when (or (numberp (car-safe t1))
! (numberp (car-safe t2)))
! (list micro)))
! low))))
;;;###autoload
(defun time-add (t1 t2)
"Add two time values. One should represent a time difference."
! (let* ((high (+ (pop t1) (pop t2)))
! (low (+ (if (consp t1) (pop t1) t1)
! (if (consp t2) (pop t2) t2)))
! (micro (+ (if (numberp (car-safe t1))
! (car t1)
! 0)
! (if (numberp (car-safe t2))
! (car t2)
! 0))))
! (when (>= micro 1000000)
! (setq low (1+ low)
! micro (- micro 1000000)))
! (when (>= low #x10000)
! (setq high (1+ high)
! low (- low #x10000)))
! (cons high
! (if (or (consp t1) (consp t2))
! (cons low
! (when (or (numberp (car-safe t1))
! (numberp (car-safe t2)))
! (list micro)))
! low))))
;;;###autoload
(defun date-to-day (date)
***************
*** 180,186 ****
(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)))
;;;###autoload
(defun safe-date-to-time (date)
--- 216,222 ----
(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."
! (/ (time-to-seconds time) (* 60 60 24)))
;;;###autoload
(defun safe-date-to-time (date)
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