An example of a non-terminating compilation with javac

gistfile1.txt

/** from http://www.reddit.com/r/programming/comments/mlbna/scala_feels_like_ejb_2/c31z0co */
interface Pong<T> {}
class Ping<T> implements Pong<Pong<? super Ping<Ping<T>>>> {
    static void Ping() {
        Pong<? super Ping<Long>> Ping = new Ping<Long>();
    }
}


> javac Ping.java

The system is out of resources.
Consult the following stack trace for details.
java.lang.StackOverflowError
    at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:568)
    at com.sun.tools.javac.code.Types$UnaryVisitor.visit(Types.java:3294)
    at com.sun.tools.javac.code.Types$23.visitClassType(Types.java:2618)
    at com.sun.tools.javac.code.Types$23.visitClassType(Types.java:2605)
    at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:568)
    at com.sun.tools.javac.code.Types$UnaryVisitor.visit(Types.java:3294)
    at com.sun.tools.javac.code.Types$23.visitClassType(Types.java:2618)
    at com.sun.tools.javac.code.Types$23.visitClassType(Types.java:2605)
    at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:568)
    at com.sun.tools.javac.code.Types$UnaryVisitor.visit(Types.java:3294)
    at com.sun.tools.javac.code.Types$23.visitClassType(Types.java:2618)
    at com.sun.tools.javac.code.Types$23.visitClassType(Types.java:2605)
    at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:568)
    at com.sun.tools.javac.code.Types$UnaryVisitor.visit(Types.java:3294)
    at com.sun.tools.javac.code.Types$23.visitClassType(Types.java:2618)
    at com.sun.tools.javac.code.Types$23.visitClassType(Types.java:2605)

Fun with Generics

I have done this before for my little pet project JATL.

class <___>{}class <>extends <<?super **<<___>>>>{void (){<? super _<>>=new ___<**>();}}

class $&lt;__&gt;{}class €&lt;£&gt;extends $&lt;$<?super €<€<£>>>>{void $(){$&lt;? super €<$>>$=new €<$>();}}