File : a-calend.ads
------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
5 -- A D A . C A L E N D A R --
-- --
-- S p e c --
-- --
-- $Revision: 1.11 $ --
10 -- --
-- Copyright (C) 1992-1997 Free Software Foundation, Inc. --
-- --
-- This specification is derived from the Ada Reference Manual for use with --
-- GNAT. The copyright notice above, and the license provisions that follow --
15 -- apply solely to the contents of the part following the private keyword. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
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-- OUT ANY WARRANTY; without even the implied warranty of 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 --
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25 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
30 -- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
35 -- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
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40 package Ada.Calendar is
type Time is private;
-- Declarations representing limits of allowed local time values. Note that
45 -- these do NOT constrain the possible stored values of time which may well
-- permit a larger range of times (this is explicitly allowed in Ada 95).
subtype Year_Number is Integer range 1901 .. 2099;
subtype Month_Number is Integer range 1 .. 12;
50 subtype Day_Number is Integer range 1 .. 31;
subtype Day_Duration is Duration range 0.0 .. 86_400.0;
function Clock return Time;
55
function Year (Date : Time) return Year_Number;
function Month (Date : Time) return Month_Number;
function Day (Date : Time) return Day_Number;
function Seconds (Date : Time) return Day_Duration;
60
procedure Split
(Date : Time;
Year : out Year_Number;
Month : out Month_Number;
65 Day : out Day_Number;
Seconds : out Day_Duration);
function Time_Of
(Year : Year_Number;
70 Month : Month_Number;
Day : Day_Number;
Seconds : Day_Duration := 0.0)
return Time;
75 function "+" (Left : Time; Right : Duration) return Time;
function "+" (Left : Duration; Right : Time) return Time;
function "-" (Left : Time; Right : Duration) return Time;
function "-" (Left : Time; Right : Time) return Duration;
80 function "<" (Left, Right : Time) return Boolean;
function "<=" (Left, Right : Time) return Boolean;
function ">" (Left, Right : Time) return Boolean;
function ">=" (Left, Right : Time) return Boolean;
85 Time_Error : exception;
private
pragma Inline (Clock);
90 pragma Inline (Year);
pragma Inline (Month);
pragma Inline (Day);
pragma Inline ("+");
95 pragma Inline ("-");
pragma Inline ("<");
pragma Inline ("<=");
pragma Inline (">");
100 pragma Inline (">=");
-- Time is represented as a signed duration from the base point which is
-- what Unix calls the EPOCH (i.e. 12 midnight (24:00:00), Dec 31st, 1969,
-- or if you prefer 0:00:00 on Jan 1st, 1970). Since Ada allows dates
105 -- before this EPOCH value, the stored duration value may be negative.
-- The time value stored is typically a GMT value, as provided in standard
-- Unix environments. If this is the case then Split and Time_Of perform
-- required conversions to and from local times. The range of times that
110 -- can be stored in Time values depends on the declaration of the type
-- Duration, which must at least cover the required Ada range represented
-- by the declaration of Year_Number, but may be larger (we take full
-- advantage of the new permission in Ada 95 to store time values outside
-- the range that would be acceptable to Split). The Duration type is a
115 -- real value representing a time interval in seconds.
type Time is new Duration;
end Ada.Calendar;