>From a588608988b5fe2c27637ad4c1783a945ea639dd Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Thu, 27 Sep 2018 18:28:27 -0700 Subject: [PATCH] time-equal, and time values of infinity and NaN * doc/lispref/os.texi (Time Calculations): Document time-equal, and the behavior on NaNs and infinities of time-less-p, time-add, time-subtract. * etc/NEWS: Mention the change. * src/editfns.c (time_arith): Change last arg from function to bool. All callers changed. Do the right thing with infinities and NaNs. (time_cmp): New function, which handlesx infinities and NaNs. (Ftime_less_p): Use it. (Ftime_equal): New function. * test/lisp/emacs-lisp/timer-tests.el (timer-test-multiple-of-time): Use it. --- doc/lispref/os.texi | 11 +++++- etc/NEWS | 8 ++++ src/editfns.c | 58 ++++++++++++++++++++++------- test/lisp/emacs-lisp/timer-tests.el | 8 ++-- 4 files changed, 66 insertions(+), 19 deletions(-) diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi index 8481fea806..67b78aea74 100644 --- a/doc/lispref/os.texi +++ b/doc/lispref/os.texi @@ -1736,17 +1736,26 @@ Time Calculations @defun time-less-p t1 t2 This returns @code{t} if time value @var{t1} is less than time value @var{t2}. +The result is @code{nil} if either argument is a NaN. address@hidden defun + address@hidden time-equal t1 t2 +This returns @code{t} if @var{t1} and @var{t2} are equal time values. +The result is @code{nil} if either argument is a NaN. @end defun @defun time-subtract t1 t2 This returns the time difference @var{t1} @minus{} @var{t2} between -two time values, as a time value. If you need the difference in units +two time values, as a time value. However, the result is a float +if either argument is a float infinity or address@hidden +If you need the difference in units of elapsed seconds, use @code{float-time} (@pxref{Time of Day, float-time}) to convert the result into seconds. @end defun @defun time-add t1 t2 This returns the sum of two time values, as a time value. +However, the result is a float if either argument is a float infinity or address@hidden One argument should represent a time difference rather than a point in time, either as a list or as a single number of elapsed seconds. Here is how to add a number of seconds to a time value: diff --git a/etc/NEWS b/etc/NEWS index 2a609e4027..4dd4260b29 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -951,6 +951,14 @@ like file-attributes that compute file sizes and other attributes, functions like process-id that compute process IDs, and functions like user-uid and group-gid that compute user and group IDs. ++++ +** 'time-add', 'time-subtract', and 'time-less-p' now accept +infinities and NaNs too, and propagate them or return nil like +floating-point operators do. + ++++ +** New function 'time-equal' compares time values for equality. + ** define-minor-mode automatically documents the meaning of ARG. +++ diff --git a/src/editfns.c b/src/editfns.c index ec6e8ba98d..acd80bbf31 100644 --- a/src/editfns.c +++ b/src/editfns.c @@ -1589,13 +1589,21 @@ time_subtract (struct lisp_time ta, struct lisp_time tb) } static Lisp_Object -time_arith (Lisp_Object a, Lisp_Object b, - struct lisp_time (*op) (struct lisp_time, struct lisp_time)) +time_arith (Lisp_Object a, Lisp_Object b, bool subtract) { + if (FLOATP (a) && !isfinite (XFLOAT_DATA (a))) + { + double da = XFLOAT_DATA (a); + double db = XFLOAT_DATA (Ffloat_time (b)); + return make_float (subtract ? da - db : da + db); + } + if (FLOATP (b) && !isfinite (XFLOAT_DATA (b))) + return subtract ? make_float (-XFLOAT_DATA (b)) : b; + int alen, blen; struct lisp_time ta = lisp_time_struct (a, &alen); struct lisp_time tb = lisp_time_struct (b, &blen); - struct lisp_time t = op (ta, tb); + struct lisp_time t = (subtract ? time_subtract : time_add) (ta, tb); if (FIXNUM_OVERFLOW_P (t.hi)) time_overflow (); Lisp_Object val = Qnil; @@ -1623,7 +1631,7 @@ A nil value for either argument stands for the current time. See `current-time-string' for the various forms of a time value. */) (Lisp_Object a, Lisp_Object b) { - return time_arith (a, b, time_add); + return time_arith (a, b, false); } DEFUN ("time-subtract", Ftime_subtract, Stime_subtract, 2, 2, 0, @@ -1633,7 +1641,30 @@ A nil value for either argument stands for the current time. See `current-time-string' for the various forms of a time value. */) (Lisp_Object a, Lisp_Object b) { - return time_arith (a, b, time_subtract); + return time_arith (a, b, true); +} + +/* Return negative, 0, positive if a < b, a == b, a > b respectively. + Return positive if either a or b is a NaN; this is good enough + for the current callers. */ +static int +time_cmp (Lisp_Object a, Lisp_Object b) +{ + if ((FLOATP (a) && !isfinite (XFLOAT_DATA (a))) + || (FLOATP (b) && !isfinite (XFLOAT_DATA (b)))) + { + double da = FLOATP (a) ? XFLOAT_DATA (a) : 0; + double db = FLOATP (b) ? XFLOAT_DATA (b) : 0; + return da < db ? -1 : da != db; + } + + int alen, blen; + struct lisp_time ta = lisp_time_struct (a, &alen); + struct lisp_time tb = lisp_time_struct (b, &blen); + return (ta.hi != tb.hi ? (ta.hi < tb.hi ? -1 : 1) + : ta.lo != tb.lo ? (ta.lo < tb.lo ? -1 : 1) + : ta.us != tb.us ? (ta.us < tb.us ? -1 : 1) + : ta.ps < tb.ps ? -1 : ta.ps != tb.ps); } DEFUN ("time-less-p", Ftime_less_p, Stime_less_p, 2, 2, 0, @@ -1642,14 +1673,14 @@ A nil value for either argument stands for the current time. See `current-time-string' for the various forms of a time value. */) (Lisp_Object t1, Lisp_Object t2) { - int t1len, t2len; - struct lisp_time a = lisp_time_struct (t1, &t1len); - struct lisp_time b = lisp_time_struct (t2, &t2len); - return ((a.hi != b.hi ? a.hi < b.hi - : a.lo != b.lo ? a.lo < b.lo - : a.us != b.us ? a.us < b.us - : a.ps < b.ps) - ? Qt : Qnil); + return time_cmp (t1, t2) < 0 ? Qt : Qnil; +} + +DEFUN ("time-equal", Ftime_equal, Stime_equal, 2, 2, 0, + doc: /* Return non-nil if T1 and T2 are equal time values. */) + (Lisp_Object t1, Lisp_Object t2) +{ + return time_cmp (t1, t2) == 0 ? Qt : Qnil; } @@ -5734,6 +5765,7 @@ it to be non-nil. */); defsubr (&Scurrent_time); defsubr (&Stime_add); defsubr (&Stime_subtract); + defsubr (&Stime_equal); defsubr (&Stime_less_p); defsubr (&Sget_internal_run_time); defsubr (&Sformat_time_string); diff --git a/test/lisp/emacs-lisp/timer-tests.el b/test/lisp/emacs-lisp/timer-tests.el index 1d3ba757f6..0e40cdf442 100644 --- a/test/lisp/emacs-lisp/timer-tests.el +++ b/test/lisp/emacs-lisp/timer-tests.el @@ -40,10 +40,8 @@ (should (debug-timer-check)) t)) (ert-deftest timer-test-multiple-of-time () - (should (zerop - (float-time - (time-subtract - (timer-next-integral-multiple-of-time '(0 0 0 1) (1+ (ash 1 53))) - (list (ash 1 (- 53 16)) 1)))))) + (should (time-equal + (timer-next-integral-multiple-of-time '(0 0 0 1) (1+ (ash 1 53))) + (list (ash 1 (- 53 16)) 1)))) ;;; timer-tests.el ends here -- 2.17.1