On Fri, Nov 18, 2011 at 10:04 AM, Vijay Saraswat <vi...@saraswat.org> wrote:
> A student in my class recently asked how to do enums in X10.
>
> Here is a simple illustration, using structs.
>
> Best,
> Vijay
>
> Go, Pluto!
>
> package examples;
>
> /**
> * An illustration of how to do enum's in X10.
> * Implement an enum as a struct with private fields. It may have as
> many methods
> * as you want.
> *
> * <p>Make the constructors private. Have public static fields for all
> the desired
> * values of the enum type. Have a static field (e.g. Planets below) that
> * contains an Iterator over the array of all the fields.
> *
> * <p>Define an equals method if you wish equality to reflect equality
> on a subset
> * of the fields. Otherwise the default equality should suffice.
> *
> */
> public struct Planet {
>
> private val mass:Double;
> private val radius:Double;
> private val name:String;
> private def this(m:Double, r:Double,n:String) {
> this.mass=m;
> this.radius=r;
> this.name=n;
> }
>
> public static val G:Double=6.67e-11;
>
> public def mass():Double=mass;
> public def radius():Double=radius;
> public def name():String=name;
>
> public def gOnSurface():Double= G*mass/(radius*radius);
> public def weightOnSurface(m:Double):Double=m*gOnSurface();
> public def toString()=name;
> public static def toPlanet(s:String):Planet {
> for (p in Planets)
> if (s.equalsIgnoreCase(p.name()))
> return p;
> throw new RuntimeException("No such planet.");
> }
> public static val MERCURY=Planet(3.303e23,2.4937e6,"Mercury");
> public static val VENUS=Planet(4.869e24,6.0518e6,"Venus");
> public static val EARTH=Planet(5.976e24,6.37184e6,"Earth");
> public static val MARS=Planet(6.421e23,3.3972e6,"Mars");
> public static val JUPITER=Planet(1.9e27,7.1492e7,"Jupiter");
> public static val SATURN=Planet(5.688e26,6.0268e7,"Saturn");
> public static val URANUS=Planet(8.686e25,2.5559e7,"Uranus");
> public static val NEPTUNE=Planet(1.024e26,2.4746e7,"Neptune");
> public static val PLUTO=Planet(1.27e22,2.274e7,"Pluto");
>
> public static val Planets=[MERCURY,VENUS,EARTH,MARS,JUPITER,SATURN,
> URANUS,NEPTUNE,PLUTO].values();
>
> public static def main(args:Array[String](0)) {
> if (args.size !=2) {
> Console.OUT.println("Usage: <weight:Double> <name:String>");
> return;
> }
> val w = Int.parseInt(args(0));
> val q = toPlanet(args(1));
> for (p in Planets) {
> if (q !=p)
> Console.OUT.printf("You weigh %s kg on %s.%n",
> [p.weightOnSurface(w),p]);
> }
> }
> }
Also see http://jira.codehaus.org/browse/XTENLANG-1118 .
Igor
------------------------------------------------------------------------------
All the data continuously generated in your IT infrastructure
contains a definitive record of customers, application performance,
security threats, fraudulent activity, and more. Splunk takes this
data and makes sense of it. IT sense. And common sense.
http://p.sf.net/sfu/splunk-novd2d
_______________________________________________
X10-users mailing list
X10-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/x10-users
