org.joe_e
Class JoeE

java.lang.Object
  org.joe_e.JoeE

public class JoeE
extends Object

Joe-E core library functions. These provide fundamental features, similar to the methods in java.lang.System, such as the interface to the overlay type system.

Method Summary

static Error	abort(Error reason) Aborts the current flow of control.
static boolean	instanceOf(Object obj, Class<?> type) Tests whether the specified object belongs to the specified type in the overlay type system.
static boolean	isFrozen(Object x) Is the object one-level deep immutable?
static boolean	isSubtypeOf(Class<?> c1, Class<?> c2) Tests whether the first class is a subtype of the second in the overlay type system.

Methods inherited from class java.lang.Object

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

Method Detail

instanceOf

public static boolean instanceOf(Object obj,
                                 Class<?> type)

Tests whether the specified object belongs to the specified type in the overlay type system. The equivalent of the Java instanceof operator, for the overlay type system.

Parameters:

obj - the object to test

type - the type to test membership of

Returns:

true if the specified object belongs to the specified type in the overlay type system.

isSubtypeOf

public static boolean isSubtypeOf(Class<?> c1,
                                  Class<?> c2)

Tests whether the first class is a subtype of the second in the overlay type system.

Parameters:

c1 - the potential subtype

c2 - the potential supertype

Returns:

true if the first argument is a subtype of the second in the overlay type system

abort

public static Error abort(Error reason)

Aborts the current flow of control. This method invokes the currently registered error handler, which should preclude continued execution of Joe-E code.

Parameters:

reason - reason for the abort

Returns:

an error to throw

isFrozen

public static boolean isFrozen(Object x)

Is the object one-level deep immutable?

Parameters:

x - candidate object

Returns:

true if x is one-level deep immutable, false if it might not be