RosettaCodeData/Task/Date-manipulation/Ada/date-manipulation.ada

98 lines
2.8 KiB
Ada

with Ada.Calendar;
with Ada.Calendar.Formatting;
with Ada.Calendar.Time_Zones;
with Ada.Integer_Text_IO;
with Ada.Text_IO;
procedure Date_Manipulation is
type Month_Name_T is
(January, February, March, April, May, June,
July, August, September, October, November, December);
type Time_Zone_Name_T is (EST, Lisbon);
type Period_T is (AM, PM);
package TZ renames Ada.Calendar.Time_Zones;
use type TZ.Time_Offset;
Time_Zone_Offset : array (Time_Zone_Name_T) of TZ.Time_Offset :=
(EST => -5 * 60,
Lisbon => 0);
Period_Offset : array (Period_T) of Natural :=
(AM => 0,
PM => 12);
package Month_Name_IO is
new Ada.Text_IO.Enumeration_IO (Month_Name_T);
package Time_Zone_Name_IO is
new Ada.Text_IO.Enumeration_IO (Time_Zone_Name_T);
package Period_IO is
new Ada.Text_IO.Enumeration_IO (Period_T);
package Std renames Ada.Calendar;
use type Std.Time;
package Fmt renames Std.Formatting;
function To_Number (Name : Month_Name_T) return Std.Month_Number is
begin
return Std.Month_Number (Month_Name_T'Pos (Name) + 1);
end;
function To_Time (S : String) return Std.Time is
Month : Month_Name_T;
Day : Std.Day_Number;
Year : Std.Year_Number;
Hour : Fmt.Hour_Number;
Minute : Fmt.Minute_Number;
Period : Period_T;
Time_Zone : Time_Zone_Name_T;
I : Natural;
begin
Month_Name_IO.Get
(From => S, Item => Month, Last => I);
Ada.Integer_Text_IO.Get
(From => S (I + 1 .. S'Last), Item => Day, Last => I);
Ada.Integer_Text_IO.Get
(From => S (I + 1 .. S'Last), Item => Year, Last => I);
Ada.Integer_Text_IO.Get
(From => S (I + 1 .. S'Last), Item => Hour, Last => I);
Ada.Integer_Text_IO.Get
(From => S (I + 2 .. S'Last), Item => Minute, Last => I);
-- here we start 2 chars down to skip the ':'
Period_IO.Get
(From => S (I + 1 .. S'Last), Item => Period, Last => I);
Time_Zone_Name_IO.Get
(From => S (I + 1 .. S'Last), Item => Time_Zone, Last => I);
return Fmt.Time_Of
(Year => Year,
Month => To_Number (Month),
Day => Day,
Hour => Hour + Period_Offset (Period),
Minute => Minute,
Second => 0,
Time_Zone => Time_Zone_Offset (Time_Zone));
end;
function Img
(Date : Std.Time; Zone : Time_Zone_Name_T) return String is
begin
return
Fmt.Image (Date => Date, Time_Zone => Time_Zone_Offset (Zone)) &
" " & Time_Zone_Name_T'Image (Zone);
end;
T1, T2 : Std.Time;
use Ada.Text_IO;
begin
T1 := To_Time ("March 7 2009 7:30pm EST");
T2 := T1 + 12.0 * 60.0 * 60.0;
Put_Line ("T1 => " & Img (T1, EST) & " = " & Img (T1, Lisbon));
Put_Line ("T2 => " & Img (T2, EST) & " = " & Img (T2, Lisbon));
end;