Data update

Task/Constrained-genericity/Ada/constrained-genericity-1.adb

@@ -0,0 +1,24 @@
+with Ada.Containers.Indefinite_Vectors;
+
+package Nutrition is
+   type Food is interface;
+   procedure Eat (Object : in out Food) is abstract;
+
+end Nutrition;
+
+with Ada.Containers;
+with Nutrition;
+
+generic
+   type New_Food is new Nutrition.Food;
+package Food_Boxes is
+
+  package Food_Vectors is
+      new Ada.Containers.Indefinite_Vectors
+          (  Index_Type   => Positive,
+             Element_Type => New_Food
+          );
+
+   subtype Food_Box is Food_Vectors.Vector;
+
+end Food_Boxes;

Task/Constrained-genericity/Ada/constrained-genericity-2.adb

@@ -0,0 +1,8 @@
+type Banana is new Food with null record;
+overriding procedure Eat (Object : in out Banana) is null;
+package Banana_Box is new Food_Boxes (Banana);
+
+type Tomato is new Food with null record;
+overriding procedure Eat (Object : in out Tomato) is null;
+package Tomato_Box is new Food_Boxes (Tomato);
+-- We have declared Banana and Tomato as a Food.

Task/Constrained-genericity/Pluto/constrained-genericity.pluto

@@ -0,0 +1,36 @@
+-- Abstract class.
+class eatable
+    function eat() end -- override in child class
+end
+
+class foodbox extends eatable
+    private contents
+
+    function __construct(contents)
+        if !contents:checkall(|c| -> c instanceof eatable) then
+            error("All foodbox elements must be eatable.")
+        end
+        self.contents = contents
+    end
+
+    function getContents() return self.contents end
+end
+
+-- Inherits from eatable and overrides eat() method.
+class pie extends eatable
+    function __construct(private filling) end
+
+    function eat()
+        print($"{self.filling} pie, yum!")
+    end
+end
+
+-- Not an eatable
+class bicycle end
+
+local items = {new pie("Apple"), new pie("Gooseberry")}
+local fb = new foodbox(items)
+fb:getContents():foreach(|item| -> item:eat())
+print()
+items:insert(new bicycle())
+fb = new foodbox(items)  -- throws an error because bicycle not eatable

Task/Constrained-genericity/V-(Vlang)/constrained-genericity.v

@@ -0,0 +1,20 @@
+interface Eatable {
+    eat()
+}
+
+type Foodbox = []Eatable
+
+type Peelfirst = string
+
+fn (f Peelfirst) eat() {
+    // peel code goes here
+    println("mm, that ${f} was good!")
+}
+
+fn main() {
+    mut fb := Foodbox{}
+    fb << [Peelfirst("banana"), Peelfirst("mango")]
+    // fb would print as `[Eatable(Peelfirst(banana)), Eatable(Peelfirst(mango))]`
+    f0 := fb[0]
+    f0.eat()
+}