Polymorphism: Difference between revisions
Rename Perl 6 -> Raku, alphabetize, minor clean-up
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=={{header|C}}==
* See [[Polymorphism/C]]
=={{header|C sharp|C#}}==
<lang csharp>using System;
class Point
{
protected int x, y;
public Point() : this(0) {}
public Point(int x) : this(x,0) {}
public Point(int x, int y) { this.x = x; this.y = y; }
public int X { get { return x; } set { x = value; } }
public int Y { get { return y; } set { y = value; } }
public virtual void print() { System.Console.WriteLine("Point"); }
}
public class Circle : Point
{
private int r;
public Circle(Point p) : this(p,0) { }
public Circle(Point p, int r) : base(p) { this.r = r; }
public Circle() : this(0) { }
public Circle(int x) : this(x,0) { }
public Circle(int x, int y) : this(x,y,0) { }
public Circle(int x, int y, int r) : base(x,y) { this.r = r; }
public int R { get { return r; } set { r = value; } }
public override void print() { System.Console.WriteLine("Circle"); }
public static void main(String args[])
{
Point p = new Point();
Point c = new Circle();
p.print();
c.print();
}
}</lang>
=={{header|C++}}==
Line 694 ⟶ 728:
c->print();
return 0;
}</lang>
Line 1,332:
<lang ela>c = circleX 12
c.x //Evaluates to 12</lang>
=={{header|Elena}}==
ELENA 5.0 :
Line 1,385 ⟶ 1,386:
Circle
</pre>
=={{header|F Sharp|F#}}==
Polymorphism is achieved by defining an interface <code>Printable</code> which is implemented by <code>Point</code> and <code>Circle</code>. (In real code, you should override the <code>ToString</code> method which every class inherits from <code>Object</code>.)
Due to the use of optional parameters, we only need one constructor for every class. No accessors are necessary because we use public read-only properties. (Mutable properties are possible, too, but should be avoided in idiomatic code.)
<lang fsharp>type Printable =
abstract member Print : unit -> unit
type Point(?x, ?y) =
member t.x = defaultArg x 0.0
member t.y = defaultArg y 0.0
interface Printable with
member t.Print() = printfn "Point(x:%f, y:%f)" t.x t.y
type Circle(?center, ?radius) =
member t.center = defaultArg center (new Point())
member t.radius = defaultArg radius 1.0
interface Printable with
member t.Print() =
printfn "Circle(x:%f, y:%f, r:%f)" t.center.x t.center.y t.radius</lang>
=={{header|Factor}}==
Line 1,685 ⟶ 1,707:
</lang>
=={{header|Go}}==
<lang go>package main
Line 2,350 ⟶ 2,352:
return Circle:new{x = self.x, y = self.y, r = self.r}
end</lang>
=={{header|M2000 Interpreter}}==
Line 3,024 ⟶ 3,025:
A circle of radius 6 centered at location (0,2)
</pre>
=={{header|OxygenBasic}}==
Line 3,225:
print $c->r, "\n"; # accessor autogenerated
}</lang>
=={{header|Phix}}==
Line 3,884 ⟶ 3,854:
"<circle% <point% 3 0> 5>"
</pre>
=={{header|Raku}}==
(formerly Perl 6)
{{Works with|rakudo|2015-11-30}}
All appropriate constructors, initializers, accessors, and destructors are provided by default, but may be explicitly declared for flexibility.
To create only readonly accessors for better encapsulation, leave out all the "is rw" traits.
Here we demonstrate that accessors can behave like variables and may be assigned.
<lang perl6>class Point {
has Real $.x is rw = 0;
has Real $.y is rw = 0;
method Str { $.perl }
}
class Circle {
has Point $.p is rw = Point.new;
has Real $.r is rw = 0;
method Str { $.perl }
}
my $c = Circle.new(p => Point.new(x => 1, y => 2), r => 3);
say $c;
$c.p.x = (-10..10).pick;
$c.p.y = (-10..10).pick;
$c.r = (0..10).pick;
say $c;</lang>
In this case we define the Str coercion method polymorphically, which is used by say or print to format the contents of the object.
We could also have defined print methods directly.
We could have factored this method out to a common role and composed it into each class.
We could also have defined multi subs outside of the class, like this:
<lang perl6>multi print (Point $p) { $p.perl.print }
multi print (Circle $c) { $c.perl.print }</lang>
=={{header|Ruby}}==
Line 3,968 ⟶ 3,969:
}</lang>
=={{header|Seed7}}==
[http://seed7.sourceforge.net/manual/objects.htm Seed7 object orientation] works via interfaces.
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