frege.runtime

Class BlackHole

java.lang.Object

frege.runtime.BlackHole

public final class BlackHole
extends java.lang.Object

Provides a uniq object that is useless and cannot be casted to any other type, except Object.

This is used in the runtime to detect so called black holes. Black holes are expressions that demand evaluation of themselves while they are evaluated.

Consider:

let a = a + 1 in a + 42

Note that the following is not a blackhole:

let a = 1:a in take 20 a

because evaluation of 1:a does not demand evaluation of a.

Field Summary

Fields

Modifier and Type	Field and Description
static BlackHole	it A uniq object that is useless and cannot be casted to any other type, except Object.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	BlackHole()

Method Summary

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

it

public static final BlackHole it

A uniq object that is useless and cannot be casted to any other type, except Object.

Constructor Detail

BlackHole

private BlackHole()