Pizza

Pizza is an open-source superset of the Java programming language with the following new features:

• Generics
• Function pointers
• Class cases and pattern matching (a.k.a Algebraic types)

In August 2001 the developers made a compiler capable of working with Java. Speed tests have shown the Pizza compiler works twice as fast as the Java compiler, but as it currently performs no optimization the resulting application is rather cumbersome. Most Pizza applications can run in a Java environment, but certain cases will cause problems.

Work on Pizza has more or less stopped since 2002. Its main developers have concentrated instead on the GJ project, another attempt to add generics to Java which was eventually adopted into the official language version 1.5. The pattern matching and other functional programming-like features have been further developed in the Scala programming language. Martin Odersky remarked, "we wanted to integrate the functional and object-oriented parts in a cleaner way than what we were able to achieve before with the Pizza language... in Scala I think we achieved a much smoother integration between the two."^[1]

Example

public final class Main {
  public int main(String args[]) {
    System.out.println(
      new Lines(new DataInputStream(System.in))
        .takeWhile(nonEmpty)
        .map(fun(String s) -> int { return Integer.parseInt(s); })
        .reduceLeft(0, fun(int x, int y) -> int { return x + y; }));
  }
}

References

1. ^ http://www.artima.com/scalazine/articles/goals_of_scala.html The Goals of Scala's Design

External links

• Pizza Compiler