Ada Programming/Libraries/GNAT.Calendar

-- --                                                                         -- --                         GNAT RUN-TIME COMPONENTS                         -- --                                                                         -- --                         G N A T. C A L E N D A R                       -- --                                                                         -- --                                 S p e c                                  -- --                                                                         -- --          Copyright (C) 1999-2016, Free Software Foundation, Inc.         -- --                                                                         -- -- 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 3,  or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the  implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. -- --                                                                         -- -- As a special exception under Section 7 of GPL version 3, you are granted -- -- additional permissions described in the GCC Runtime Library Exception,  -- -- version 3.1, as published by the Free Software Foundation. -- --                                                                         -- -- In particular,  you can freely  distribute your programs  built with the -- -- GNAT Pro compiler, including any required library run-time units, using -- -- any licensing terms of your choosing. See the AdaCore Software License -- -- for full details. -- --                                                                         -- -- GNAT was originally developed  by the GNAT team at  New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc.     -- --                                                                         -- --

-- This package extends Ada.Calendar to handle Hour, Minute, Second, -- Second_Duration and Day_Of_Week and Day_In_Year from Calendar.Time. -- Second_Duration precision depends on the target clock precision. -- -- GNAT.Calendar provides the same kind of abstraction found in Ada.Calendar. -- It provides Split and Time_Of to build and split a Time data. And it -- provides accessor functions to get only one of Hour, Minute, Second, -- Second_Duration. Other functions are to access more advanced values like -- Day_Of_Week, Day_In_Year and Week_In_Year.

with Ada.Calendar.Formatting; with Interfaces.C;

package GNAT.Calendar is

type Day_Name is    (Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday); pragma Ordered (Day_Name);

subtype Hour_Number        is Natural range 0 .. 23;  subtype Minute_Number       is Natural range 0 .. 59;  subtype Second_Number       is Natural range 0 .. 59;  subtype Second_Duration     is Ada.Calendar.Day_Duration range 0.0 .. 1.0;  subtype Day_In_Year_Number  is Positive range 1 .. 366;  subtype Week_In_Year_Number is Positive range 1 .. 53;

No_Time : constant Ada.Calendar.Time; -- A constant set to the first date that can be represented by the type -- Time. It can be used to indicate an uninitialized date.

function Hour      (Date : Ada.Calendar.Time) return Hour_Number; function Minute    (Date : Ada.Calendar.Time) return Minute_Number; function Second    (Date : Ada.Calendar.Time) return Second_Number; function Sub_Second (Date : Ada.Calendar.Time) return Second_Duration; -- Hour, Minute, Second and Sub_Second returns the complete time data for -- the Date (H:M:S.SS). See Ada.Calendar for Year, Month, Day accessors. -- Second_Duration precision depends on the target clock precision.

function Day_Of_Week (Date : Ada.Calendar.Time) return Day_Name; -- Return the day name

function Day_In_Year (Date : Ada.Calendar.Time) return Day_In_Year_Number; -- Return the day number in the year. (1st January is day 1 and 31st  --  December is day 365 or 366 for leap year).

procedure Split (Date      : Ada.Calendar.Time;      Year       : out Ada.Calendar.Year_Number;      Month      : out Ada.Calendar.Month_Number;      Day        : out Ada.Calendar.Day_Number;      Hour       : out Hour_Number;      Minute     : out Minute_Number;      Second     : out Second_Number;      Sub_Second : out Second_Duration); -- Split a standard Ada.Calendar.Time value in date data (Year, Month, Day) -- and Time data (Hour, Minute, Second, Sub_Second).

procedure Split_At_Locale (Date      : Ada.Calendar.Time;      Year       : out Ada.Calendar.Year_Number;      Month      : out Ada.Calendar.Month_Number;      Day        : out Ada.Calendar.Day_Number;      Hour       : out Hour_Number;      Minute     : out Minute_Number;      Second     : out Second_Number;      Sub_Second : out Second_Duration); -- Split a standard Ada.Calendar.Time value in date data (Year, Month, Day) -- and Time data (Hour, Minute, Second, Sub_Second). This version of Split -- utilizes the time zone and DST bias of the locale (equivalent to Clock). -- Due to this simplified behavior, the implementation does not require -- expensive system calls on targets such as Windows. -- WARNING: Split_At_Locale is no longer aware of historic events and may -- produce inaccurate results over DST changes which occurred in the past.

function Time_Of (Year      : Ada.Calendar.Year_Number;      Month      : Ada.Calendar.Month_Number;      Day        : Ada.Calendar.Day_Number;      Hour       : Hour_Number;      Minute     : Minute_Number;      Second     : Second_Number;      Sub_Second : Second_Duration := 0.0) return Ada.Calendar.Time; -- Return an Ada.Calendar.Time data built from the date and time values

function Time_Of_At_Locale (Year      : Ada.Calendar.Year_Number;      Month      : Ada.Calendar.Month_Number;      Day        : Ada.Calendar.Day_Number;      Hour       : Hour_Number;      Minute     : Minute_Number;      Second     : Second_Number;      Sub_Second : Second_Duration := 0.0) return Ada.Calendar.Time; -- Return an Ada.Calendar.Time data built from the date and time values. -- This version of Time_Of utilizes the time zone and DST bias of the -- locale (equivalent to Clock). Due to this simplified behavior, the -- implementation does not require expensive system calls on targets such -- as Windows. -- WARNING: Split_At_Locale is no longer aware of historic events and may -- produce inaccurate results over DST changes which occurred in the past.

function Week_In_Year (Date : Ada.Calendar.Time) return Week_In_Year_Number; -- Return the week number as defined in ISO 8601. A week always starts on  --  a Monday and the first week of a particular year is the one containing -- the first Thursday. A year may have 53 weeks when January 1st is a  --  Wednesday and the year is leap or January 1st is a Thursday. Note that -- the last days of December may belong to the first week on the next year -- and conversely, the first days of January may belong to the last week -- of the last year.

procedure Year_Week_In_Year (Date : Ada.Calendar.Time;     Year : out Ada.Calendar.Year_Number;      Week : out Week_In_Year_Number); -- Return the week number as defined in ISO 8601 along with the year in   --  which the week occurs.

-- C timeval conversion

-- C timeval represent a duration (used in Select for example). This -- structure is composed of a number of seconds and a number of micro -- seconds. The timeval structure is not exposed here because its -- definition is target dependent. Interface to C programs is done via a  --  pointer to timeval structure.

type timeval is private;

function To_Duration (T : not null access timeval) return Duration; function To_Timeval (D : Duration) return timeval;

private -- This is a dummy declaration that should be the largest possible timeval -- structure of all supported targets.

type timeval is array (1 .. 3) of Interfaces.C.long;

function Julian_Day (Year : Ada.Calendar.Year_Number;      Month : Ada.Calendar.Month_Number;      Day   : Ada.Calendar.Day_Number) return Integer; -- Compute Julian day number --  --  The code of this function is a modified version of algorithm 199 from -- the Collected Algorithms of the ACM. The author of algorithm 199 is  --  Robert G. Tantzen.

No_Time : constant Ada.Calendar.Time := Ada.Calendar.Formatting.Time_Of (Ada.Calendar.Year_Number'First,                 Ada.Calendar.Month_Number'First,                  Ada.Calendar.Day_Number'First,                  Time_Zone => 0); -- Use Time_Zone => 0 to be the same binary representation in any timezone

end GNAT.Calendar; |GNAT.Calendar