September Morn Update

Task/Polymorphism/Elena/polymorphism.elena

@@ -1,46 +1,46 @@
-import extensions.
+import extensions;
 
 class Point
 {
-    int prop X :: _x.
-    int prop Y :: _y.
+    prop int X;
+    prop int Y;
 
-    constructor new(IntNumber x, IntNumber y)
-    [
-        _x := x.
-        _y := y.
-    ]
+    constructor(int x, int y)
+    {
+        X := x;
+        Y := y
+    }
 
-    constructor new
-        <= new(0,0).
+    constructor()
+        <= (0,0);
 
-    print [ console printLine("Point") ]
+    print() { console.printLine("Point") }
 }
 
-class Circle :: Point
+class Circle : Point
 {
-    int prop R :: _r.
+    prop int R;
 
-    constructor new
-        <= new(0).
+    constructor()
+        <= (0);
 
-    constructor new(IntNumber r)
-        <= new(0, 0, r).
+    constructor(int r)
+        <= (0, 0, r);
 
-    constructor new(IntNumber x, IntNumber y, IntNumber r)
-        <= new(x, y);
-    [
-        _r := r.
-    ]
+    constructor(int x, int y, int r)
+        <= (x, y)
+    {
+        R := r
+    }
 
-    print [ console printLine("Circle") ]
+    print() { console.printLine("Circle") }
 }
 
-program =
-[
-    var p := Point new.
-    var c := Circle new.
+public program()
+{
+    Point p := new Point();
+    Point c := new Circle();
 
-    p print.
-    c print.
-].
+    p.print();
+    c.print()
+}

Task/Polymorphism/Golo/polymorphism.golo

@@ -0,0 +1,73 @@
+#!/usr/bin/env golosh
+----
+This module demonstrates Golo's version of polymorphism.
+----
+module Polymorphism
+
+# Each struct automatically gets a constructor and also accessor and assignment methods for each field.
+# For example, the constructor for Point is Point(1, 2)
+# and the accessor methods are x() and y()
+# and the assignment methods are x(10) and y(10).
+
+struct Point = { x, y }
+struct Circle = { x, y, r }
+
+# Augmentations are the way to give your struct methods.
+# They're like extension methods in C# or Xtend.
+
+augment Point {
+
+  function print = |this| { println("Point " + this: x() + " " + this: y()) }
+}
+
+augment Circle {
+
+  function print = |this| { println("Circle " + this: x() + " " + this: y() + " " + this: r()) }
+}
+
+# You can define functions with the same name as your struct that work
+# basically like constructors.
+
+----
+A contructor with no arguments that initializes all fields to 0
+----
+function Point = -> Point(0, 0)
+
+----
+This is the copy constructor when the argument is another point
+----
+function Point = |x| -> match {
+  when x oftype Point.class then Point(x: x(), x: y())
+  otherwise Point(x, 0)
+}
+
+----
+A contructor with no arguments that initializes all fields to 0
+----
+function Circle = -> Circle(0, 0, 0)
+
+----
+This is the copy constructor when the argument is another circle
+----
+function Circle = |x| -> match {
+  when x oftype Circle.class then Circle(x: x(), x: y(), x: r())
+  otherwise Circle(x, 0, 0)
+}
+
+----
+This one initializes the radius to zero
+----
+function Circle = |x, y| -> Circle(x, y, 0)
+
+
+function main = |args| {
+  let p = Point(10, 20)
+  let c = Circle(10, 20, 30)
+  let shapes = vector[
+    Point(), Point(1), Point(1, 2), Point(p),
+    Circle(), Circle(1), Circle(1, 2), Circle(1, 2, 3), Circle(c)
+  ]
+  foreach shape in shapes {
+    shape: print()
+  }
+}