tasks a-s

Task/Partial-function-application/Ada/partial-function-application.ada

@@ -0,0 +1,50 @@
+with Ada.Text_IO;
+
+procedure Partial_Function_Application is
+
+   type Sequence is array(Positive range <>) of Integer;
+
+   -- declare a function FS with a generic parameter F and a normal parameter S
+   generic
+      with function F(I: Integer) return Integer; -- generic parameter
+   function FS (S: Sequence) return Sequence;
+
+   -- define FS
+   function FS (S: Sequence) return Sequence is
+      Result: Sequence(S'First .. S'Last);
+   begin
+      for Idx in S'Range loop
+         Result(Idx) := F(S(Idx));
+      end loop;
+      return Result;
+   end FS;
+
+   -- define functions F1 and F2
+   function F1(I: Integer) return Integer is
+   begin
+      return 2*I;
+   end F1;
+
+   function F2(I: Integer) return Integer is
+   begin
+      return I**2;
+   end F2;
+
+   -- instantiate the function FS by F1 and F2 (partially apply F1 and F2 to FS)
+   function FSF1 is new FS(F1);
+   function FSF2 is new FS(F2);
+
+   procedure Print(S: Sequence) is
+   begin
+      for Idx in S'Range loop
+         Ada.Text_IO.Put(Integer'Image(S(Idx)));
+      end loop;
+      Ada.Text_IO.New_Line;
+   end Print;
+
+begin
+   Print(FSF1((0,1,2,3)));
+   Print(FSF2((0,1,2,3)));
+   Print(FSF1((2,4,6,8)));
+   Print(FSF2((2,4,6,8)));
+end Partial_Function_Application;