gcc/ada/g-calend.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                         G N A T . C A L E N D A R                        --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --                                                                          --
  10 --          Copyright (C) 1999-2001 Free Software Foundation, Inc.          --
  11 --                                                                          --
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  17 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
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  19 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
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  21 -- MA 02111-1307, USA.                                                      --
  22 --                                                                          --
  23 -- As a special exception,  if other files  instantiate  generics from this --
  24 -- unit, or you link  this unit with other files  to produce an executable, --
  25 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  26 -- covered  by the  GNU  General  Public  License.  This exception does not --
  27 -- however invalidate  any other reasons why  the executable file  might be --
  28 -- covered by the  GNU Public License.                                      --
  29 --                                                                          --
  30 -- GNAT was originally developed  by the GNAT team at  New York University. --
  31 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
  32 --                                                                          --
  33 ------------------------------------------------------------------------------
  34
  35 --  This package extends Ada.Calendar to handle Hour, Minute, Second,
  36 --  Second_Duration and Day_Of_Week and Day_In_Year from Calendar.Time.
  37 --  Second_Duration precision depends on the target clock precision.
  38 --
  39 --  GNAT.Calendar provides the same kind of abstraction found in
  40 --  Ada.Calendar. It provides Split and Time_Of to build and split a Time
  41 --  data. And it provides accessor functions to get only one of Hour, Minute,
  42 --  Second, Second_Duration. Other functions are to access more advanced
  43 --  valueas like Day_Of_Week, Day_In_Year and Week_In_Year.
  44
  45 with Ada.Calendar;
  46 with Interfaces.C;
  47
  48 package GNAT.Calendar is
  49
  50    type Day_Name is
  51      (Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday);
  52
  53    subtype Hour_Number         is Natural range 0 .. 23;
  54    subtype Minute_Number       is Natural range 0 .. 59;
  55    subtype Second_Number       is Natural range 0 .. 59;
  56    subtype Second_Duration     is Ada.Calendar.Day_Duration range 0.0 .. 1.0;
  57    subtype Day_In_Year_Number  is Positive range 1 .. 366;
  58    subtype Week_In_Year_Number is Positive range 1 .. 53;
  59
  60    function Hour       (Date : Ada.Calendar.Time) return Hour_Number;
  61    function Minute     (Date : Ada.Calendar.Time) return Minute_Number;
  62    function Second     (Date : Ada.Calendar.Time) return Second_Number;
  63    function Sub_Second (Date : Ada.Calendar.Time) return Second_Duration;
  64    --  Hour, Minute, Sedond and Sub_Second returns the complete time data for
  65    --  the Date (H:M:S.SS). See Ada.Calendar for Year, Month, Day accessors.
  66    --  Second_Duration precision depends on the target clock precision.
  67
  68    function Day_Of_Week (Date : Ada.Calendar.Time) return Day_Name;
  69    --  Return the day name.
  70
  71    function Day_In_Year (Date : Ada.Calendar.Time) return Day_In_Year_Number;
  72    --  Returns the day number in the year. (1st January is day 1 and 31st
  73    --  December is day 365 or 366 for leap year).
  74
  75    function Week_In_Year (Date : Ada.Calendar.Time) return Week_In_Year_Number;
  76    --  Returns the week number in the year with Monday as first day of week
  77
  78    procedure Split
  79      (Date       : Ada.Calendar.Time;
  80       Year       : out Ada.Calendar.Year_Number;
  81       Month      : out Ada.Calendar.Month_Number;
  82       Day        : out Ada.Calendar.Day_Number;
  83       Hour       : out Hour_Number;
  84       Minute     : out Minute_Number;
  85       Second     : out Second_Number;
  86       Sub_Second : out Second_Duration);
  87    --  Split the standard Ada.Calendar.Time data in date data (Year, Month,
  88    --  Day) and Time data (Hour, Minute, Second, Sub_Second)
  89
  90    function Time_Of
  91      (Year       : Ada.Calendar.Year_Number;
  92       Month      : Ada.Calendar.Month_Number;
  93       Day        : Ada.Calendar.Day_Number;
  94       Hour       : Hour_Number;
  95       Minute     : Minute_Number;
  96       Second     : Second_Number;
  97       Sub_Second : Second_Duration := 0.0)
  98       return Ada.Calendar.Time;
  99    --  Returns an Ada.Calendar.Time data built from the date and time values.
 100
 101    --  C timeval conversion
 102
 103    --  C timeval represent a duration (used in Select for example). This
 104    --  structure is composed of a number of seconds and a number of micro
 105    --  seconds. The timeval structure is not exposed here because its
 106    --  definition is target dependent. Interface to C programs is done via a
 107    --  pointer to timeval structure.
 108
 109    type timeval is private;
 110
 111    function To_Duration (T : access timeval) return Duration;
 112    function To_Timeval  (D : Duration) return timeval;
 113
 114 private
 115    --  This is a dummy declaration that should be the largest possible timeval
 116    --  structure of all supported targets.
 117
 118    type timeval is array (1 .. 2) of Interfaces.C.long;
 119
 120    function Julian_Day
 121      (Year  : Ada.Calendar.Year_Number;
 122       Month : Ada.Calendar.Month_Number;
 123       Day   : Ada.Calendar.Day_Number)
 124       return  Integer;
 125    --  Compute Julian day number.
 126    --
 127    --  The code of this function is a modified version of algorithm
 128    --  199 from the Collected Algorithms of the ACM.
 129    --  The author of algorithm 199 is Robert G. Tantzen.
 130 end GNAT.Calendar;