org.jruby.RubyNil Maven / Gradle / Ivy
/***** BEGIN LICENSE BLOCK *****
* Version: EPL 2.0/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Eclipse Public
* License Version 2.0 (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-v20.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
* Copyright (C) 2001-2004 Jan Arne Petersen
* Copyright (C) 2002-2004 Anders Bengtsson
* Copyright (C) 2004 Thomas E Enebo
* Copyright (C) 2004 Charles O Nutter
* Copyright (C) 2004 Stefan Matthias Aust
*
* 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.jcodings.specific.USASCIIEncoding;
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;
import org.jruby.util.ByteList;
/**
*
* @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) {
throw runtime.newTypeError("allocator undefined for NilClass");
}
};
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
*
*/
@Override
@JRubyMethod
public IRubyObject inspect() {
return RubyNil.inspect(getRuntime());
}
static final byte[] nilBytes = new byte[] { 'n','i','l' }; // RubyString.newUSASCIIString(runtime, "nil")
private static final ByteList nil = new ByteList(nilBytes, USASCIIEncoding.INSTANCE);
static RubyString inspect(Ruby runtime) {
return RubyString.newStringShared(runtime, runtime.getString(), nil);
}
/** nil_and
*
*/
@JRubyMethod(name = "&", required = 1)
public static RubyBoolean op_and(ThreadContext context, IRubyObject recv, IRubyObject obj) {
return context.fals;
}
/** 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, 0);
}
/** nilclass_rationalize
*
*/
@JRubyMethod(optional = 1)
public static IRubyObject rationalize(ThreadContext context, IRubyObject recv, IRubyObject[] args) {
return to_r(context, recv);
}
@Override
public T toJava(Class target) {
if (target.isPrimitive()) {
if (target == boolean.class) {
return (T) Boolean.FALSE;
} else if (target == char.class) {
return (T) (Character) '\0';
} else {
switch (target.getSimpleName().charAt(0)) {
case 'b': return (T) (Byte) (byte) 0;
case 's': return (T) (Short) (short) 0;
case 'i': return (T) (Integer) 0;
case 'l': return (T) (Long) 0L;
case 'f': return (T) (Float) 0.0F;
case 'd': return (T) (Double) 0.0;
}
}
}
return null;
}
}
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