[Emacs-diffs] Changes to emacs/lispref/os.texi

[Richard M. Stallman]

Index: emacs/lispref/os.texi
diff -c emacs/lispref/os.texi:1.45 emacs/lispref/os.texi:1.46
*** emacs/lispref/os.texi:1.45  Thu Oct 25 11:30:32 2001
--- emacs/lispref/os.texi       Thu Jan 31 23:28:28 2002
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*** 23,28 ****
--- 23,29 ----
  * Time of Day::               Getting the current time.
  * Time Conversion::     Converting a time from numeric form to a string, or
                            to calendrical data (or vice versa).
+ * Time Calculations::   Adding, subtracting, comparing times, etc.
  * Timers::            Setting a timer to call a function at a certain time.
  * Terminal Input::      Recording terminal input for debugging.
  * Terminal Output::     Recording terminal output for debugging.
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*** 1032,1037 ****
--- 1033,1043 ----
  traditional Gregorian years do; for example, the year number @minus{}37
  represents the Gregorian year 38 address@hidden
  
+ @defun date-to-time string
+ This function parses the time-string @var{string} and returns the
+ corresponding time value.
+ @end defun
+ 
  @defun format-time-string format-string &optional time universal
  This function converts @var{time} (or the current time, if @var{time} is
  omitted) to a string according to @var{format-string}.  The argument
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*** 1146,1151 ****
--- 1152,1163 ----
  string using that same coding system.
  @end defun
  
+ @defun seconds-to-time seconds
+ This function converts @var{seconds}, a floating point number of
+ seconds since the epoch, to a time value and returns that.  To perform
+ the inverse conversion, use @code{float-time}.
+ @end defun
+ 
  @defun decode-time time
  This function converts a time value into calendrical information.  The
  return value is a list of nine elements, as follows:
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*** 1215,1220 ****
--- 1227,1271 ----
  
  The operating system puts limits on the range of possible time values;
  if you try to encode a time that is out of range, an error results.
+ @end defun
+ 
+ @node Time Calculations
+ @section Time Calculations
+ 
+   These functions perform calendrical computations using time values
+ (the kind of list that @code{current-time} returns).
+ 
+ @defun time-less-p t1 t2
+ This returns @code{t} if time value @var{t1} is less than time value
+ @var{t2}.
+ @end defun
+ 
+ @defun time-subtract t1 t2
+ This returns the time difference @var{t1} @minus{} @var{t2} between
+ two time values, in the same format as a time value.
+ @end defun
+ 
+ @defun time-add t1 t2
+ This returns the sum of two time values, one of which ought to
+ represent a time difference rather than a point in time.
+ Here is how to add a number of seconds to a time value:
+ 
+ @example
+ (time-add @var{time} (seconds-to-time @var{seconds}))
+ @end example
+ @end defun
+ 
+ @defun time-to-days time
+ This function returns the number of days between the beginning of year
+ 1 and @var{time}.
+ @end defun
+ 
+ @defun time-to-day-in-year time
+ This returns the day number within the year corresponding to @var{time}.
+ @end defun
+ 
+ @defun date-leap-year-p year
+ This function returns @code{t} if @var{year} is a leap year.
  @end defun
  
  @node Timers