RubyNil.java
/***** BEGIN LICENSE BLOCK *****
* Version: EPL 1.0/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Eclipse Public
* License Version 1.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.eclipse.org/legal/epl-v10.html
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* Copyright (C) 2001 Alan Moore <alan_moore@gmx.net>
* Copyright (C) 2001-2004 Jan Arne Petersen <jpetersen@uni-bonn.de>
* Copyright (C) 2002-2004 Anders Bengtsson <ndrsbngtssn@yahoo.se>
* Copyright (C) 2004 Thomas E Enebo <enebo@acm.org>
* Copyright (C) 2004 Charles O Nutter <headius@headius.com>
* Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the EPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the EPL, the GPL or the LGPL.
***** END LICENSE BLOCK *****/
package org.jruby;
import org.jruby.anno.JRubyMethod;
import org.jruby.anno.JRubyClass;
import org.jruby.compiler.Constantizable;
import org.jruby.runtime.ClassIndex;
import org.jruby.runtime.ObjectAllocator;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.runtime.opto.OptoFactory;
/**
*
* @author jpetersen
*/
@JRubyClass(name="NilClass")
public class RubyNil extends RubyObject implements Constantizable {
private final int hashCode;
private final Object constant;
public RubyNil(Ruby runtime) {
super(runtime, runtime.getNilClass(), false);
flags |= NIL_F | FALSE_F | FROZEN_F;
if (RubyInstanceConfig.CONSISTENT_HASHING_ENABLED) {
// default to a fixed value
this.hashCode = 34;
} else {
// save the object id based hash code;
this.hashCode = System.identityHashCode(this);
}
constant = OptoFactory.newConstantWrapper(IRubyObject.class, this);
}
public static final ObjectAllocator NIL_ALLOCATOR = new ObjectAllocator() {
@Override
public IRubyObject allocate(Ruby runtime, RubyClass klass) {
return runtime.getNil();
}
};
public static RubyClass createNilClass(Ruby runtime) {
RubyClass nilClass = runtime.defineClass("NilClass", runtime.getObject(), NIL_ALLOCATOR);
runtime.setNilClass(nilClass);
nilClass.setClassIndex(ClassIndex.NIL);
nilClass.setReifiedClass(RubyNil.class);
nilClass.defineAnnotatedMethods(RubyNil.class);
nilClass.getMetaClass().undefineMethod("new");
// FIXME: This is causing a verification error for some reason
//nilClass.dispatcher = callbackFactory.createDispatcher(nilClass);
return nilClass;
}
@Override
public ClassIndex getNativeClassIndex() {
return ClassIndex.NIL;
}
@Override
public boolean isImmediate() {
return true;
}
@Override
public RubyClass getSingletonClass() {
return metaClass;
}
@Override
public Class<?> getJavaClass() {
return void.class;
}
/**
* @see org.jruby.compiler.Constantizable
*/
@Override
public Object constant() {
return constant;
}
// Methods of the Nil Class (nil_*):
/** nil_to_i
*
*/
@JRubyMethod
public static RubyFixnum to_i(ThreadContext context, IRubyObject recv) {
return RubyFixnum.zero(recv.getRuntime());
}
/**
* nil_to_f
*
*/
@JRubyMethod
public static RubyFloat to_f(ThreadContext context, IRubyObject recv) {
return RubyFloat.newFloat(context.runtime, 0.0D);
}
/** nil_to_s
*
*/
@JRubyMethod
public static RubyString to_s(ThreadContext context, IRubyObject recv) {
return RubyString.newEmptyString(context.runtime);
}
/** nil_to_a
*
*/
@JRubyMethod
public static RubyArray to_a(ThreadContext context, IRubyObject recv) {
return context.runtime.newEmptyArray();
}
@JRubyMethod
public static RubyHash to_h(ThreadContext context, IRubyObject recv) {
return RubyHash.newSmallHash(context.runtime);
}
/** nil_inspect
*
*/
@JRubyMethod
public static RubyString inspect(ThreadContext context, IRubyObject recv) {
return RubyString.newUSASCIIString(context.runtime, "nil");
}
/** nil_and
*
*/
@JRubyMethod(name = "&", required = 1)
public static RubyBoolean op_and(ThreadContext context, IRubyObject recv, IRubyObject obj) {
return context.runtime.getFalse();
}
/** nil_or
*
*/
@JRubyMethod(name = "|", required = 1)
public static RubyBoolean op_or(ThreadContext context, IRubyObject recv, IRubyObject obj) {
return context.runtime.newBoolean(obj.isTrue());
}
/** nil_xor
*
*/
@JRubyMethod(name = "^", required = 1)
public static RubyBoolean op_xor(ThreadContext context, IRubyObject recv, IRubyObject obj) {
return context.runtime.newBoolean(obj.isTrue());
}
@JRubyMethod(name = "nil?")
public IRubyObject nil_p() {
return getRuntime().getTrue();
}
@JRubyMethod
public RubyFixnum hash(ThreadContext context) {
return context.runtime.newFixnum(hashCode());
}
@Override
public int hashCode() {
return hashCode;
}
@Override
public RubyFixnum id() {
return getRuntime().newFixnum(8);
}
@Override
public IRubyObject taint(ThreadContext context) {
return this;
}
/** nilclass_to_c
*
*/
@JRubyMethod
public static IRubyObject to_c(ThreadContext context, IRubyObject recv) {
return RubyComplex.newComplexCanonicalize(context, RubyFixnum.zero(context.runtime));
}
/** nilclass_to_r
*
*/
@JRubyMethod
public static IRubyObject to_r(ThreadContext context, IRubyObject recv) {
return RubyRational.newRationalCanonicalize(context, RubyFixnum.zero(context.runtime));
}
/** nilclass_rationalize
*
*/
@JRubyMethod(optional = 1)
public static IRubyObject rationalize(ThreadContext context, IRubyObject recv, IRubyObject[] args) {
return to_r(context, recv);
}
@Override
public Object toJava(Class target) {
if (target.isPrimitive()) {
if (target == Boolean.TYPE) {
return Boolean.FALSE;
} else if (target == Byte.TYPE) {
return (byte)0;
} else if (target == Short.TYPE) {
return (short)0;
} else if (target == Character.TYPE) {
return (char)0;
} else if (target == Integer.TYPE) {
return 0;
} else if (target == Long.TYPE) {
return (long)0;
} else if (target == Float.TYPE) {
return (float)0;
} else if (target == Double.TYPE) {
return (double)0;
}
}
return null;
}
}