Add initial prototype.

1-base/lace/source/lace-time.ads

@@ -0,0 +1,57 @@
+package lace.Time
+--
+-- Time of day.
+--
+is
+   type Hours        is range 0 ..      23;
+   type Minutes      is range 0 ..      59;
+   type Seconds      is range 0 ..      59;
+   type milliSeconds is range 0 ..     999;
+   type microSeconds is range 0 .. 999_999;
+
+
+   function to_milliSeconds (From : microSeconds) return milliSeconds;
+   function to_microSeconds (From : milliSeconds) return microSeconds;
+
+
+   type Item is
+      record
+         Hours        : Time.Hours;
+         Minutes      : Time.Minutes;
+         Seconds      : Time.Seconds;
+         microSeconds : Time.microSeconds;
+      end record;
+
+   zero_Time : constant Time.item;
+
+
+   function to_Duration (From  : in Time.item)         return Duration;
+   function to_Time     (From  : in standard.Duration) return Time.item;
+
+   function to_Time     (Hours        : in Time.Hours        := 0;
+                         Minutes      : in Time.Minutes      := 0;
+                         Seconds      : in Time.Seconds      := 0;
+                         microSeconds : in Time.microSeconds := 0) return Time.item;
+
+   function Image (Time  : in Item)   return String;     -- Format: HH:MM:SS.mmmmmm
+   function Value (Image : in String) return Time.item;
+
+
+   Overflow  : exception;
+   Underflow : exception;
+
+   function "+" (Left, Right : in Time.item) return Time.item;
+   function "-" (Left, Right : in Time.item) return Time.item;
+
+   function "+" (Left  : in Time.item;   Right : in Duration) return Time.item;
+   function "-" (Left  : in Time.item;   Right : in Duration) return Time.item;
+
+
+
+private
+   zero_Time : constant Time.item := (Hours        => 0,
+                                      Minutes      => 0,
+                                      Seconds      => 0,
+                                      microSeconds => 0);
+
+end lace.Time;