summaryrefslogtreecommitdiff
path: root/gcc/ada/g-calend.ads
blob: 9dd5ae00a845eab0bd818426499c9cc9f4113efd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
------------------------------------------------------------------------------
--                                                                          --
--                         GNAT RUN-TIME COMPONENTS                         --
--                                                                          --
--                         G N A T . C A L E N D A R                        --
--                                                                          --
--                                 S p e c                                  --
--                                                                          --
--          Copyright (C) 1999-2010, 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.               --
--                                                                          --
-- You should have received a copy of the GNU General Public License and    --
-- a copy of the GCC Runtime Library Exception along with this program;     --
-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
-- <http://www.gnu.org/licenses/>.                                          --
--                                                                          --
-- 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;
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 the standard Ada.Calendar.Time data in date data (Year, Month,
   --  Day) and Time data (Hour, Minute, Second, Sub_Second)

   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 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 .. 2) 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.Time_Of
                 (Ada.Calendar.Year_Number'First,
                  Ada.Calendar.Month_Number'First,
                  Ada.Calendar.Day_Number'First);

end GNAT.Calendar;