/*
 * Copyright (c) 2010, 2016, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package jdk.nashorn.internal.objects;

import static jdk.nashorn.internal.runtime.ECMAErrors.rangeError;
import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
import static jdk.nashorn.internal.runtime.PropertyDescriptor.VALUE;
import static jdk.nashorn.internal.runtime.PropertyDescriptor.WRITABLE;
import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.isValidArrayIndex;
import static jdk.nashorn.internal.runtime.arrays.ArrayLikeIterator.arrayLikeIterator;
import static jdk.nashorn.internal.runtime.arrays.ArrayLikeIterator.reverseArrayLikeIterator;
import static jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor.CALLSITE_STRICT;

import java.lang.invoke.MethodHandle;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.Callable;
import jdk.dynalink.CallSiteDescriptor;
import jdk.dynalink.linker.GuardedInvocation;
import jdk.dynalink.linker.LinkRequest;
import jdk.nashorn.api.scripting.JSObject;
import jdk.nashorn.internal.objects.annotations.Attribute;
import jdk.nashorn.internal.objects.annotations.Constructor;
import jdk.nashorn.internal.objects.annotations.Function;
import jdk.nashorn.internal.objects.annotations.Getter;
import jdk.nashorn.internal.objects.annotations.ScriptClass;
import jdk.nashorn.internal.objects.annotations.Setter;
import jdk.nashorn.internal.objects.annotations.SpecializedFunction;
import jdk.nashorn.internal.objects.annotations.SpecializedFunction.LinkLogic;
import jdk.nashorn.internal.objects.annotations.Where;
import jdk.nashorn.internal.runtime.Context;
import jdk.nashorn.internal.runtime.Debug;
import jdk.nashorn.internal.runtime.JSType;
import jdk.nashorn.internal.runtime.OptimisticBuiltins;
import jdk.nashorn.internal.runtime.PropertyDescriptor;
import jdk.nashorn.internal.runtime.PropertyMap;
import jdk.nashorn.internal.runtime.ScriptObject;
import jdk.nashorn.internal.runtime.ScriptRuntime;
import jdk.nashorn.internal.runtime.Undefined;
import jdk.nashorn.internal.runtime.arrays.ArrayData;
import jdk.nashorn.internal.runtime.arrays.ArrayIndex;
import jdk.nashorn.internal.runtime.arrays.ArrayLikeIterator;
import jdk.nashorn.internal.runtime.arrays.ContinuousArrayData;
import jdk.nashorn.internal.runtime.arrays.IntElements;
import jdk.nashorn.internal.runtime.arrays.IteratorAction;
import jdk.nashorn.internal.runtime.arrays.NumericElements;
import jdk.nashorn.internal.runtime.linker.Bootstrap;
import jdk.nashorn.internal.runtime.linker.InvokeByName;

Runtime representation of a JavaScript array. NativeArray only holds numeric
keyed values. All other values are stored in spill.
/**
 * Runtime representation of a JavaScript array. NativeArray only holds numeric
 * keyed values. All other values are stored in spill.
 */
@ScriptClass("Array")
public final class NativeArray extends ScriptObject implements OptimisticBuiltins {
    private static final Object JOIN                     = new Object();
    private static final Object EVERY_CALLBACK_INVOKER   = new Object();
    private static final Object SOME_CALLBACK_INVOKER    = new Object();
    private static final Object FOREACH_CALLBACK_INVOKER = new Object();
    private static final Object MAP_CALLBACK_INVOKER     = new Object();
    private static final Object FILTER_CALLBACK_INVOKER  = new Object();
    private static final Object REDUCE_CALLBACK_INVOKER  = new Object();
    private static final Object CALL_CMP                 = new Object();
    private static final Object TO_LOCALE_STRING         = new Object();

    /*
     * Constructors.
     */
    NativeArray() {
        this(ArrayData.initialArray());
    }

    NativeArray(final long length) {
        this(ArrayData.allocate(length));
    }

    NativeArray(final int[] array) {
        this(ArrayData.allocate(array));
    }

    NativeArray(final double[] array) {
        this(ArrayData.allocate(array));
    }

    NativeArray(final long[] array) {
        this(ArrayData.allocate(array.length));

        ArrayData arrayData = this.getArray();
        Class<?> widest = int.class;

        for (int index = 0; index < array.length; index++) {
            final long value = array[index];

            if (widest == int.class && JSType.isRepresentableAsInt(value)) {
                arrayData = arrayData.set(index, (int) value, false);
            } else if (widest != Object.class && JSType.isRepresentableAsDouble(value)) {
                arrayData = arrayData.set(index, (double) value, false);
                widest = double.class;
            } else {
                arrayData = arrayData.set(index, (Object) value, false);
                widest = Object.class;
            }
        }

        this.setArray(arrayData);
    }

    NativeArray(final Object[] array) {
        this(ArrayData.allocate(array.length));

        ArrayData arrayData = this.getArray();

        for (int index = 0; index < array.length; index++) {
            final Object value = array[index];

            if (value == ScriptRuntime.EMPTY) {
                arrayData = arrayData.delete(index);
            } else {
                arrayData = arrayData.set(index, value, false);
            }
        }

        this.setArray(arrayData);
    }

    NativeArray(final ArrayData arrayData) {
        this(arrayData, Global.instance());
    }

    NativeArray(final ArrayData arrayData, final Global global) {
        super(global.getArrayPrototype(), $nasgenmap$);
        setArray(arrayData);
        setIsArray();
    }

    @Override
    protected GuardedInvocation findGetIndexMethod(final CallSiteDescriptor desc, final LinkRequest request) {
        final GuardedInvocation inv = getArray().findFastGetIndexMethod(getArray().getClass(), desc, request);
        if (inv != null) {
            return inv;
        }
        return super.findGetIndexMethod(desc, request);
    }

    @Override
    protected GuardedInvocation findSetIndexMethod(final CallSiteDescriptor desc, final LinkRequest request) {
        final GuardedInvocation inv = getArray().findFastSetIndexMethod(getArray().getClass(), desc, request);
        if (inv != null) {
            return inv;
        }

        return super.findSetIndexMethod(desc, request);
    }

    private static InvokeByName getJOIN() {
        return Global.instance().getInvokeByName(JOIN,
                new Callable<InvokeByName>() {
                    @Override
                    public InvokeByName call() {
                        return new InvokeByName("join", ScriptObject.class);
                    }
                });
    }

    private static MethodHandle createIteratorCallbackInvoker(final Object key, final Class<?> rtype) {
        return Global.instance().getDynamicInvoker(key,
            new Callable<MethodHandle>() {
                @Override
                public MethodHandle call() {
                    return Bootstrap.createDynamicCallInvoker(rtype, Object.class, Object.class, Object.class,
                        double.class, Object.class);
                }
            });
    }

    private static MethodHandle getEVERY_CALLBACK_INVOKER() {
        return createIteratorCallbackInvoker(EVERY_CALLBACK_INVOKER, boolean.class);
    }

    private static MethodHandle getSOME_CALLBACK_INVOKER() {
        return createIteratorCallbackInvoker(SOME_CALLBACK_INVOKER, boolean.class);
    }

    private static MethodHandle getFOREACH_CALLBACK_INVOKER() {
        return createIteratorCallbackInvoker(FOREACH_CALLBACK_INVOKER, void.class);
    }

    private static MethodHandle getMAP_CALLBACK_INVOKER() {
        return createIteratorCallbackInvoker(MAP_CALLBACK_INVOKER, Object.class);
    }

    private static MethodHandle getFILTER_CALLBACK_INVOKER() {
        return createIteratorCallbackInvoker(FILTER_CALLBACK_INVOKER, boolean.class);
    }

    private static MethodHandle getREDUCE_CALLBACK_INVOKER() {
        return Global.instance().getDynamicInvoker(REDUCE_CALLBACK_INVOKER,
                new Callable<MethodHandle>() {
                    @Override
                    public MethodHandle call() {
                        return Bootstrap.createDynamicCallInvoker(Object.class, Object.class,
                             Undefined.class, Object.class, Object.class, double.class, Object.class);
                    }
                });
    }

    private static MethodHandle getCALL_CMP() {
        return Global.instance().getDynamicInvoker(CALL_CMP,
                new Callable<MethodHandle>() {
                    @Override
                    public MethodHandle call() {
                        return Bootstrap.createDynamicCallInvoker(double.class,
                            Object.class, Object.class, Object.class, Object.class);
                    }
                });
    }

    private static InvokeByName getTO_LOCALE_STRING() {
        return Global.instance().getInvokeByName(TO_LOCALE_STRING,
                new Callable<InvokeByName>() {
                    @Override
                    public InvokeByName call() {
                        return new InvokeByName("toLocaleString", ScriptObject.class, String.class);
                    }
                });
    }

    // initialized by nasgen
    private static PropertyMap $nasgenmap$;

    @Override
    public String getClassName() {
        return "Array";
    }

    @Override
    public Object getLength() {
        final long length = getArray().length();
        assert length >= 0L;
        if (length <= Integer.MAX_VALUE) {
            return (int)length;
        }
        return length;
    }

    private boolean defineLength(final long oldLen, final PropertyDescriptor oldLenDesc, final PropertyDescriptor desc, final boolean reject) {
        // Step 3a
        if (!desc.has(VALUE)) {
            return super.defineOwnProperty("length", desc, reject);
        }

        // Step 3b
        final PropertyDescriptor newLenDesc = desc;

        // Step 3c and 3d - get new length and convert to long
        final long newLen = NativeArray.validLength(newLenDesc.getValue());

        // Step 3e - note that we need to convert to int or double as long is not considered a JS number type anymore
        newLenDesc.setValue(JSType.toNarrowestNumber(newLen));

        // Step 3f
        // increasing array length - just need to set new length value (and attributes if any) and return
        if (newLen >= oldLen) {
            return super.defineOwnProperty("length", newLenDesc, reject);
        }

        // Step 3g
        if (!oldLenDesc.isWritable()) {
            if (reject) {
                throw typeError("property.not.writable", "length", ScriptRuntime.safeToString(this));
            }
            return false;
        }

        // Step 3h and 3i
        final boolean newWritable = !newLenDesc.has(WRITABLE) || newLenDesc.isWritable();
        if (!newWritable) {
            newLenDesc.setWritable(true);
        }

        // Step 3j and 3k
        final boolean succeeded = super.defineOwnProperty("length", newLenDesc, reject);
        if (!succeeded) {
            return false;
        }

        // Step 3l
        // make sure that length is set till the point we can delete the old elements
        long o = oldLen;
        while (newLen < o) {
            o--;
            final boolean deleteSucceeded = delete(o, false);
            if (!deleteSucceeded) {
                newLenDesc.setValue(o + 1);
                if (!newWritable) {
                    newLenDesc.setWritable(false);
                }
                super.defineOwnProperty("length", newLenDesc, false);
                if (reject) {
                    throw typeError("property.not.writable", "length", ScriptRuntime.safeToString(this));
                }
                return false;
            }
        }

        // Step 3m
        if (!newWritable) {
            // make 'length' property not writable
            final ScriptObject newDesc = Global.newEmptyInstance();
            newDesc.set(WRITABLE, false, 0);
            return super.defineOwnProperty("length", newDesc, false);
        }

        return true;
    }

    
ECMA 15.4.5.1 [[DefineOwnProperty]] ( P, Desc, Throw )
/**
     * ECMA 15.4.5.1 [[DefineOwnProperty]] ( P, Desc, Throw )
     */
    @Override
    public boolean defineOwnProperty(final Object key, final Object propertyDesc, final boolean reject) {
        final PropertyDescriptor desc = toPropertyDescriptor(Global.instance(), propertyDesc);

        // never be undefined as "length" is always defined and can't be deleted for arrays
        // Step 1
        final PropertyDescriptor oldLenDesc = (PropertyDescriptor) super.getOwnPropertyDescriptor("length");

        // Step 2
        // get old length and convert to long. Always a Long/Uint32 but we take the safe road.
        final long oldLen = JSType.toUint32(oldLenDesc.getValue());

        // Step 3
        if ("length".equals(key)) {
            // check for length being made non-writable
            final boolean result = defineLength(oldLen, oldLenDesc, desc, reject);
            if (desc.has(WRITABLE) && !desc.isWritable()) {
                setIsLengthNotWritable();
            }
            return result;
        }

        // Step 4a
        final int index = ArrayIndex.getArrayIndex(key);
        if (ArrayIndex.isValidArrayIndex(index)) {
            final long longIndex = ArrayIndex.toLongIndex(index);
            // Step 4b
            // setting an element beyond current length, but 'length' is not writable
            if (longIndex >= oldLen && !oldLenDesc.isWritable()) {
                if (reject) {
                    throw typeError("property.not.writable", Long.toString(longIndex), ScriptRuntime.safeToString(this));
                }
                return false;
            }

            // Step 4c
            // set the new array element
            final boolean succeeded = super.defineOwnProperty(key, desc, false);

            // Step 4d
            if (!succeeded) {
                if (reject) {
                    throw typeError("cant.redefine.property", key.toString(), ScriptRuntime.safeToString(this));
                }
                return false;
            }

            // Step 4e -- adjust new length based on new element index that is set
            if (longIndex >= oldLen) {
                oldLenDesc.setValue(longIndex + 1);
                super.defineOwnProperty("length", oldLenDesc, false);
            }

            // Step 4f
            return true;
        }

        // not an index property
        return super.defineOwnProperty(key, desc, reject);
    }

    
Spec. mentions use of [[DefineOwnProperty]] for indexed properties in
certain places (eg. Array.prototype.map, filter). We can not use ScriptObject.set
method in such cases. This is because set method uses inherited setters (if any)
from any object in proto chain such as Array.prototype, Object.prototype.
This method directly sets a particular element value in the current object.
Params:
index – key for property
value – value to define/**
     * Spec. mentions use of [[DefineOwnProperty]] for indexed properties in
     * certain places (eg. Array.prototype.map, filter). We can not use ScriptObject.set
     * method in such cases. This is because set method uses inherited setters (if any)
     * from any object in proto chain such as Array.prototype, Object.prototype.
     * This method directly sets a particular element value in the current object.
     *
     * @param index key for property
     * @param value value to define
     */
    @Override
    public final void defineOwnProperty(final int index, final Object value) {
        assert isValidArrayIndex(index) : "invalid array index";
        final long longIndex = ArrayIndex.toLongIndex(index);
        if (longIndex >= getArray().length()) {
            // make array big enough to hold..
            setArray(getArray().ensure(longIndex));
        }
        setArray(getArray().set(index, value, false));
    }

    
Return the array contents upcasted as an ObjectArray, regardless of
representation
Returns:
an object array/**
     * Return the array contents upcasted as an ObjectArray, regardless of
     * representation
     *
     * @return an object array
     */
    public Object[] asObjectArray() {
        return getArray().asObjectArray();
    }

    @Override
    public void setIsLengthNotWritable() {
        super.setIsLengthNotWritable();
        setArray(ArrayData.setIsLengthNotWritable(getArray()));
    }

    
ECMA 15.4.3.2 Array.isArray ( arg )
Params:
self – self reference
arg –  argument - object to check
Returns:
true if argument is an array/**
     * ECMA 15.4.3.2 Array.isArray ( arg )
     *
     * @param self self reference
     * @param arg  argument - object to check
     * @return true if argument is an array
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)
    public static boolean isArray(final Object self, final Object arg) {
        return isArray(arg) || (arg instanceof JSObject && ((JSObject)arg).isArray());
    }

    
Length getter
Params:
self – self reference
Returns:
the length of the object/**
     * Length getter
     * @param self self reference
     * @return the length of the object
     */
    @Getter(attributes = Attribute.NOT_ENUMERABLE | Attribute.NOT_CONFIGURABLE)
    public static Object length(final Object self) {
        if (isArray(self)) {
            final long length = ((ScriptObject) self).getArray().length();
            assert length >= 0L;
            // Cast to the narrowest supported numeric type to help optimistic type calculator
            if (length <= Integer.MAX_VALUE) {
                return (int) length;
            }
            return (double) length;
        }

        return 0;
    }

    
Length setter
Params:
self –   self reference
length – new length property/**
     * Length setter
     * @param self   self reference
     * @param length new length property
     */
    @Setter(attributes = Attribute.NOT_ENUMERABLE | Attribute.NOT_CONFIGURABLE)
    public static void length(final Object self, final Object length) {
        if (isArray(self)) {
            ((ScriptObject)self).setLength(validLength(length));
        }
    }

    
Prototype length getter
Params:
self – self reference
Returns:
the length of the object/**
     * Prototype length getter
     * @param self self reference
     * @return the length of the object
     */
    @Getter(name = "length", where = Where.PROTOTYPE, attributes = Attribute.NOT_ENUMERABLE | Attribute.NOT_CONFIGURABLE)
    public static Object getProtoLength(final Object self) {
        return length(self);  // Same as instance getter but we can't make nasgen use the same method for prototype
    }

    
Prototype length setter
Params:
self –   self reference
length – new length property/**
     * Prototype length setter
     * @param self   self reference
     * @param length new length property
     */
    @Setter(name = "length", where = Where.PROTOTYPE, attributes = Attribute.NOT_ENUMERABLE | Attribute.NOT_CONFIGURABLE)
    public static void setProtoLength(final Object self, final Object length) {
        length(self, length);  // Same as instance setter but we can't make nasgen use the same method for prototype
    }

    static long validLength(final Object length) {
        // ES5 15.4.5.1, steps 3.c and 3.d require two ToNumber conversions here
        final double doubleLength = JSType.toNumber(length);
        if (doubleLength != JSType.toUint32(length)) {
            throw rangeError("inappropriate.array.length", ScriptRuntime.safeToString(length));
        }
        return (long) doubleLength;
    }

    
ECMA 15.4.4.2 Array.prototype.toString ( )
Params:
self – self reference
Returns:
string representation of array/**
     * ECMA 15.4.4.2 Array.prototype.toString ( )
     *
     * @param self self reference
     * @return string representation of array
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE)
    public static Object toString(final Object self) {
        final Object obj = Global.toObject(self);
        if (obj instanceof ScriptObject) {
            final InvokeByName joinInvoker = getJOIN();
            final ScriptObject sobj = (ScriptObject)obj;
            try {
                final Object join = joinInvoker.getGetter().invokeExact(sobj);
                if (Bootstrap.isCallable(join)) {
                    return joinInvoker.getInvoker().invokeExact(join, sobj);
                }
            } catch (final RuntimeException | Error e) {
                throw e;
            } catch (final Throwable t) {
                throw new RuntimeException(t);
            }
        }

        // FIXME: should lookup Object.prototype.toString and call that?
        return ScriptRuntime.builtinObjectToString(self);
    }

    
Assert that an array is numeric, if not throw type error
Params:
self – self array to check
Returns:
true if numeric/**
     * Assert that an array is numeric, if not throw type error
     * @param self self array to check
     * @return true if numeric
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE)
    public static Object assertNumeric(final Object self) {
        if(!(self instanceof NativeArray && ((NativeArray)self).getArray().getOptimisticType().isNumeric())) {
            throw typeError("not.a.numeric.array", ScriptRuntime.safeToString(self));
        }
        return Boolean.TRUE;
    }

    
ECMA 15.4.4.3 Array.prototype.toLocaleString ( )
Params:
self – self reference
Returns:
locale specific string representation for array/**
     * ECMA 15.4.4.3 Array.prototype.toLocaleString ( )
     *
     * @param self self reference
     * @return locale specific string representation for array
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE)
    public static String toLocaleString(final Object self) {
        final StringBuilder sb = new StringBuilder();
        final Iterator<Object> iter = arrayLikeIterator(self, true);

        while (iter.hasNext()) {
            final Object obj = iter.next();

            if (obj != null && obj != ScriptRuntime.UNDEFINED) {
                final Object val = JSType.toScriptObject(obj);

                try {
                    if (val instanceof ScriptObject) {
                        final InvokeByName localeInvoker = getTO_LOCALE_STRING();
                        final ScriptObject sobj           = (ScriptObject)val;
                        final Object       toLocaleString = localeInvoker.getGetter().invokeExact(sobj);

                        if (Bootstrap.isCallable(toLocaleString)) {
                            sb.append((String)localeInvoker.getInvoker().invokeExact(toLocaleString, sobj));
                        } else {
                            throw typeError("not.a.function", "toLocaleString");
                        }
                    }
                } catch (final Error|RuntimeException t) {
                    throw t;
                } catch (final Throwable t) {
                    throw new RuntimeException(t);
                }
            }

            if (iter.hasNext()) {
                sb.append(",");
            }
        }

        return sb.toString();
    }

    
ECMA 15.4.2.2 new Array (len)
Params:
newObj – was the new operator used to instantiate this array
self –   self reference
args –   arguments (length)
Returns:
the new NativeArray/**
     * ECMA 15.4.2.2 new Array (len)
     *
     * @param newObj was the new operator used to instantiate this array
     * @param self   self reference
     * @param args   arguments (length)
     * @return the new NativeArray
     */
    @Constructor(arity = 1)
    public static NativeArray construct(final boolean newObj, final Object self, final Object... args) {
        switch (args.length) {
        case 0:
            return new NativeArray(0);
        case 1:
            final Object len = args[0];
            if (len instanceof Number) {
                long length;
                if (len instanceof Integer || len instanceof Long) {
                    length = ((Number) len).longValue();
                    if (length >= 0 && length < JSType.MAX_UINT) {
                        return new NativeArray(length);
                    }
                }

                length = JSType.toUint32(len);

                /*
                 * If the argument len is a Number and ToUint32(len) is equal to
                 * len, then the length property of the newly constructed object
                 * is set to ToUint32(len). If the argument len is a Number and
                 * ToUint32(len) is not equal to len, a RangeError exception is
                 * thrown.
                 */
                final double numberLength = ((Number) len).doubleValue();
                if (length != numberLength) {
                    throw rangeError("inappropriate.array.length", JSType.toString(numberLength));
                }

                return new NativeArray(length);
            }
            /*
             * If the argument len is not a Number, then the length property of
             * the newly constructed object is set to 1 and the 0 property of
             * the newly constructed object is set to len
             */
            return new NativeArray(new Object[]{args[0]});
            //fallthru
        default:
            return new NativeArray(args);
        }
    }

    
ECMA 15.4.2.2 new Array (len)
Specialized constructor for zero arguments - empty array
Params:
newObj – was the new operator used to instantiate this array
self –   self reference
Returns:
the new NativeArray/**
     * ECMA 15.4.2.2 new Array (len)
     *
     * Specialized constructor for zero arguments - empty array
     *
     * @param newObj was the new operator used to instantiate this array
     * @param self   self reference
     * @return the new NativeArray
     */
    @SpecializedFunction(isConstructor=true)
    public static NativeArray construct(final boolean newObj, final Object self) {
        return new NativeArray(0);
    }

    
ECMA 15.4.2.2 new Array (len)
Specialized constructor for zero arguments - empty array
Params:
newObj –  was the new operator used to instantiate this array
self –    self reference
element – first element
Returns:
the new NativeArray/**
     * ECMA 15.4.2.2 new Array (len)
     *
     * Specialized constructor for zero arguments - empty array
     *
     * @param newObj  was the new operator used to instantiate this array
     * @param self    self reference
     * @param element first element
     * @return the new NativeArray
     */
    @SpecializedFunction(isConstructor=true)
    public static Object construct(final boolean newObj, final Object self, final boolean element) {
        return new NativeArray(new Object[] { element });
    }

    
ECMA 15.4.2.2 new Array (len)
Specialized constructor for one integer argument (length)
Params:
newObj – was the new operator used to instantiate this array
self –   self reference
length – array length
Returns:
the new NativeArray/**
     * ECMA 15.4.2.2 new Array (len)
     *
     * Specialized constructor for one integer argument (length)
     *
     * @param newObj was the new operator used to instantiate this array
     * @param self   self reference
     * @param length array length
     * @return the new NativeArray
     */
    @SpecializedFunction(isConstructor=true)
    public static NativeArray construct(final boolean newObj, final Object self, final int length) {
        if (length >= 0) {
            return new NativeArray(length);
        }

        return construct(newObj, self, new Object[]{length});
    }

    
ECMA 15.4.2.2 new Array (len)
Specialized constructor for one long argument (length)
Params:
newObj – was the new operator used to instantiate this array
self –   self reference
length – array length
Returns:
the new NativeArray/**
     * ECMA 15.4.2.2 new Array (len)
     *
     * Specialized constructor for one long argument (length)
     *
     * @param newObj was the new operator used to instantiate this array
     * @param self   self reference
     * @param length array length
     * @return the new NativeArray
     */
    @SpecializedFunction(isConstructor=true)
    public static NativeArray construct(final boolean newObj, final Object self, final long length) {
        if (length >= 0L && length <= JSType.MAX_UINT) {
            return new NativeArray(length);
        }

        return construct(newObj, self, new Object[]{length});
    }

    
ECMA 15.4.2.2 new Array (len)
Specialized constructor for one double argument (length)
Params:
newObj – was the new operator used to instantiate this array
self –   self reference
length – array length
Returns:
the new NativeArray/**
     * ECMA 15.4.2.2 new Array (len)
     *
     * Specialized constructor for one double argument (length)
     *
     * @param newObj was the new operator used to instantiate this array
     * @param self   self reference
     * @param length array length
     * @return the new NativeArray
     */
    @SpecializedFunction(isConstructor=true)
    public static NativeArray construct(final boolean newObj, final Object self, final double length) {
        final long uint32length = JSType.toUint32(length);

        if (uint32length == length) {
            return new NativeArray(uint32length);
        }

        return construct(newObj, self, new Object[]{length});
    }

    
ECMA 15.4.4.4 Array.prototype.concat ( [ item1 [ , item2 [ , ... ] ] ] )
Params:
self – self reference
arg – argument
Returns:
resulting NativeArray/**
     * ECMA 15.4.4.4 Array.prototype.concat ( [ item1 [ , item2 [ , ... ] ] ] )
     *
     * @param self self reference
     * @param arg argument
     * @return resulting NativeArray
     */
    @SpecializedFunction(linkLogic=ConcatLinkLogic.class, convertsNumericArgs = false)
    public static NativeArray concat(final Object self, final int arg) {
        final ContinuousArrayData newData = getContinuousArrayDataCCE(self, Integer.class).copy(); //get at least an integer data copy of this data
        newData.fastPush(arg); //add an integer to its end
        return new NativeArray(newData);
    }

    
ECMA 15.4.4.4 Array.prototype.concat ( [ item1 [ , item2 [ , ... ] ] ] )
Params:
self – self reference
arg – argument
Returns:
resulting NativeArray/**
     * ECMA 15.4.4.4 Array.prototype.concat ( [ item1 [ , item2 [ , ... ] ] ] )
     *
     * @param self self reference
     * @param arg argument
     * @return resulting NativeArray
     */
    @SpecializedFunction(linkLogic=ConcatLinkLogic.class, convertsNumericArgs = false)
    public static NativeArray concat(final Object self, final double arg) {
        final ContinuousArrayData newData = getContinuousArrayDataCCE(self, Double.class).copy(); //get at least a number array data copy of this data
        newData.fastPush(arg); //add a double at the end
        return new NativeArray(newData);
    }

    
ECMA 15.4.4.4 Array.prototype.concat ( [ item1 [ , item2 [ , ... ] ] ] )
Params:
self – self reference
arg – argument
Returns:
resulting NativeArray/**
     * ECMA 15.4.4.4 Array.prototype.concat ( [ item1 [ , item2 [ , ... ] ] ] )
     *
     * @param self self reference
     * @param arg argument
     * @return resulting NativeArray
     */
    @SpecializedFunction(linkLogic=ConcatLinkLogic.class)
    public static NativeArray concat(final Object self, final Object arg) {
        //arg is [NativeArray] of same type.
        final ContinuousArrayData selfData = getContinuousArrayDataCCE(self);
        final ContinuousArrayData newData;

        if (arg instanceof NativeArray) {
            final ContinuousArrayData argData = (ContinuousArrayData)((NativeArray)arg).getArray();
            if (argData.isEmpty()) {
                newData = selfData.copy();
            } else if (selfData.isEmpty()) {
                newData = argData.copy();
            } else {
                final Class<?> widestElementType = selfData.widest(argData).getBoxedElementType();
                newData = ((ContinuousArrayData)selfData.convert(widestElementType)).fastConcat((ContinuousArrayData)argData.convert(widestElementType));
            }
        } else {
            newData = getContinuousArrayDataCCE(self, Object.class).copy();
            newData.fastPush(arg);
        }

        return new NativeArray(newData);
    }

    
ECMA 15.4.4.4 Array.prototype.concat ( [ item1 [ , item2 [ , ... ] ] ] )
Params:
self – self reference
args – arguments
Returns:
resulting NativeArray/**
     * ECMA 15.4.4.4 Array.prototype.concat ( [ item1 [ , item2 [ , ... ] ] ] )
     *
     * @param self self reference
     * @param args arguments
     * @return resulting NativeArray
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1)
    public static NativeArray concat(final Object self, final Object... args) {
        final ArrayList<Object> list = new ArrayList<>();

        concatToList(list, Global.toObject(self));

        for (final Object obj : args) {
            concatToList(list, obj);
        }

        return new NativeArray(list.toArray());
    }

    private static void concatToList(final ArrayList<Object> list, final Object obj) {
        final boolean isScriptArray  = isArray(obj);
        final boolean isScriptObject = isScriptArray || obj instanceof ScriptObject;
        if (isScriptArray || obj instanceof Iterable || obj instanceof JSObject || (obj != null && obj.getClass().isArray())) {
            final Iterator<Object> iter = arrayLikeIterator(obj, true);
            if (iter.hasNext()) {
                for (int i = 0; iter.hasNext(); ++i) {
                    final Object value = iter.next();
                    if (value == ScriptRuntime.UNDEFINED && isScriptObject && !((ScriptObject)obj).has(i)) {
                        // TODO: eventually rewrite arrayLikeIterator to use a three-state enum for handling
                        // UNDEFINED instead of an "includeUndefined" boolean with states SKIP, INCLUDE,
                        // RETURN_EMPTY. Until then, this is how we'll make sure that empty elements don't make it
                        // into the concatenated array.
                        list.add(ScriptRuntime.EMPTY);
                    } else {
                        list.add(value);
                    }
                }
            } else if (!isScriptArray) {
                list.add(obj); // add empty object, but not an empty array
            }
        } else {
            // single element, add it
            list.add(obj);
        }
    }

    
ECMA 15.4.4.5 Array.prototype.join (separator)
Params:
self –      self reference
separator – element separator
Returns:
string representation after join/**
     * ECMA 15.4.4.5 Array.prototype.join (separator)
     *
     * @param self      self reference
     * @param separator element separator
     * @return string representation after join
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE)
    public static String join(final Object self, final Object separator) {
        final StringBuilder    sb   = new StringBuilder();
        final Iterator<Object> iter = arrayLikeIterator(self, true);
        final String           sep  = separator == ScriptRuntime.UNDEFINED ? "," : JSType.toString(separator);

        while (iter.hasNext()) {
            final Object obj = iter.next();

            if (obj != null && obj != ScriptRuntime.UNDEFINED) {
                sb.append(JSType.toString(obj));
            }

            if (iter.hasNext()) {
                sb.append(sep);
            }
        }

        return sb.toString();
    }

    
Specialization of pop for ContinuousArrayData The link guard checks that the array is continuous AND not empty. The runtime guard checks that the guard is continuous (CCE otherwise) Primitive specialization, LinkLogic 
Params:
self – self reference
Throws:
ClassCastException – if array is empty, facilitating Undefined return value
Returns:
element popped/**
     * Specialization of pop for ContinuousArrayData
     *   The link guard checks that the array is continuous AND not empty.
     *   The runtime guard checks that the guard is continuous (CCE otherwise)
     *
     * Primitive specialization, {@link LinkLogic}
     *
     * @param self self reference
     * @return element popped
     * @throws ClassCastException if array is empty, facilitating Undefined return value
     */
    @SpecializedFunction(name="pop", linkLogic=PopLinkLogic.class)
    public static int popInt(final Object self) {
        //must be non empty IntArrayData
        return getContinuousNonEmptyArrayDataCCE(self, IntElements.class).fastPopInt();
    }

    
Specialization of pop for ContinuousArrayData Primitive specialization, LinkLogic 
Params:
self – self reference
Throws:
ClassCastException – if array is empty, facilitating Undefined return value
Returns:
element popped/**
     * Specialization of pop for ContinuousArrayData
     *
     * Primitive specialization, {@link LinkLogic}
     *
     * @param self self reference
     * @return element popped
     * @throws ClassCastException if array is empty, facilitating Undefined return value
     */
    @SpecializedFunction(name="pop", linkLogic=PopLinkLogic.class)
    public static double popDouble(final Object self) {
        //must be non empty int long or double array data
        return getContinuousNonEmptyArrayDataCCE(self, NumericElements.class).fastPopDouble();
    }

    
Specialization of pop for ContinuousArrayData Primitive specialization, LinkLogic 
Params:
self – self reference
Throws:
ClassCastException – if array is empty, facilitating Undefined return value
Returns:
element popped/**
     * Specialization of pop for ContinuousArrayData
     *
     * Primitive specialization, {@link LinkLogic}
     *
     * @param self self reference
     * @return element popped
     * @throws ClassCastException if array is empty, facilitating Undefined return value
     */
    @SpecializedFunction(name="pop", linkLogic=PopLinkLogic.class)
    public static Object popObject(final Object self) {
        //can be any data, because the numeric ones will throw cce and force relink
        return getContinuousArrayDataCCE(self, null).fastPopObject();
    }

    
ECMA 15.4.4.6 Array.prototype.pop ()
Params:
self – self reference
Returns:
array after pop/**
     * ECMA 15.4.4.6 Array.prototype.pop ()
     *
     * @param self self reference
     * @return array after pop
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE)
    public static Object pop(final Object self) {
        try {
            final ScriptObject sobj = (ScriptObject)self;

            if (bulkable(sobj)) {
                return sobj.getArray().pop();
            }

            final long len = JSType.toUint32(sobj.getLength());

            if (len == 0) {
                sobj.set("length", 0, CALLSITE_STRICT);
                return ScriptRuntime.UNDEFINED;
            }

            final long   index   = len - 1;
            final Object element = sobj.get(index);

            sobj.delete(index, true);
            sobj.set("length", index, CALLSITE_STRICT);

            return element;
        } catch (final ClassCastException | NullPointerException e) {
            throw typeError("not.an.object", ScriptRuntime.safeToString(self));
        }
    }

    
ECMA 15.4.4.7 Array.prototype.push (args...) Primitive specialization, LinkLogic 
Params:
self – self reference
arg – a primitive to push
Returns:
array length after push/**
     * ECMA 15.4.4.7 Array.prototype.push (args...)
     *
     * Primitive specialization, {@link LinkLogic}
     *
     * @param self self reference
     * @param arg a primitive to push
     * @return array length after push
     */
    @SpecializedFunction(linkLogic=PushLinkLogic.class, convertsNumericArgs = false)
    public static double push(final Object self, final int arg) {
        return getContinuousArrayDataCCE(self, Integer.class).fastPush(arg);
    }

    
ECMA 15.4.4.7 Array.prototype.push (args...) Primitive specialization, LinkLogic 
Params:
self – self reference
arg – a primitive to push
Returns:
array length after push/**
     * ECMA 15.4.4.7 Array.prototype.push (args...)
     *
     * Primitive specialization, {@link LinkLogic}
     *
     * @param self self reference
     * @param arg a primitive to push
     * @return array length after push
     */
    @SpecializedFunction(linkLogic=PushLinkLogic.class, convertsNumericArgs = false)
    public static double push(final Object self, final double arg) {
        return getContinuousArrayDataCCE(self, Double.class).fastPush(arg);
    }

    
ECMA 15.4.4.7 Array.prototype.push (args...) Primitive specialization, LinkLogic 
Params:
self – self reference
arg – a primitive to push
Returns:
array length after push/**
     * ECMA 15.4.4.7 Array.prototype.push (args...)
     *
     * Primitive specialization, {@link LinkLogic}
     *
     * @param self self reference
     * @param arg a primitive to push
     * @return array length after push
     */
    @SpecializedFunction(name="push", linkLogic=PushLinkLogic.class)
    public static double pushObject(final Object self, final Object arg) {
        return getContinuousArrayDataCCE(self, Object.class).fastPush(arg);
    }

    
ECMA 15.4.4.7 Array.prototype.push (args...)
Params:
self – self reference
args – arguments to push
Returns:
array length after pushes/**
     * ECMA 15.4.4.7 Array.prototype.push (args...)
     *
     * @param self self reference
     * @param args arguments to push
     * @return array length after pushes
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1)
    public static Object push(final Object self, final Object... args) {
        try {
            final ScriptObject sobj   = (ScriptObject)self;

            if (bulkable(sobj) && sobj.getArray().length() + args.length <= JSType.MAX_UINT) {
                final ArrayData newData = sobj.getArray().push(true, args);
                sobj.setArray(newData);
                return JSType.toNarrowestNumber(newData.length());
            }

            long len = JSType.toUint32(sobj.getLength());
            for (final Object element : args) {
                sobj.set(len++, element, CALLSITE_STRICT);
            }
            sobj.set("length", len, CALLSITE_STRICT);

            return JSType.toNarrowestNumber(len);
        } catch (final ClassCastException | NullPointerException e) {
            throw typeError(Context.getGlobal(), e, "not.an.object", ScriptRuntime.safeToString(self));
        }
    }

    
ECMA 15.4.4.7 Array.prototype.push (args...) specialized for single object argument
Params:
self – self reference
arg – argument to push
Returns:
array after pushes/**
     * ECMA 15.4.4.7 Array.prototype.push (args...) specialized for single object argument
     *
     * @param self self reference
     * @param arg argument to push
     * @return array after pushes
     */
    @SpecializedFunction
    public static double push(final Object self, final Object arg) {
        try {
            final ScriptObject sobj = (ScriptObject)self;
            final ArrayData arrayData = sobj.getArray();
            final long length = arrayData.length();
            if (bulkable(sobj) && length < JSType.MAX_UINT) {
                sobj.setArray(arrayData.push(true, arg));
                return length + 1;
            }

            long len = JSType.toUint32(sobj.getLength());
            sobj.set(len++, arg, CALLSITE_STRICT);
            sobj.set("length", len, CALLSITE_STRICT);
            return len;
        } catch (final ClassCastException | NullPointerException e) {
            throw typeError("not.an.object", ScriptRuntime.safeToString(self));
        }
    }

    
ECMA 15.4.4.8 Array.prototype.reverse ()
Params:
self – self reference
Returns:
reversed array/**
     * ECMA 15.4.4.8 Array.prototype.reverse ()
     *
     * @param self self reference
     * @return reversed array
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE)
    public static Object reverse(final Object self) {
        try {
            final ScriptObject sobj   = (ScriptObject)self;
            final long         len    = JSType.toUint32(sobj.getLength());
            final long         middle = len / 2;

            for (long lower = 0; lower != middle; lower++) {
                final long    upper       = len - lower - 1;
                final Object  lowerValue  = sobj.get(lower);
                final Object  upperValue  = sobj.get(upper);
                final boolean lowerExists = sobj.has(lower);
                final boolean upperExists = sobj.has(upper);

                if (lowerExists && upperExists) {
                    sobj.set(lower, upperValue, CALLSITE_STRICT);
                    sobj.set(upper, lowerValue, CALLSITE_STRICT);
                } else if (!lowerExists && upperExists) {
                    sobj.set(lower, upperValue, CALLSITE_STRICT);
                    sobj.delete(upper, true);
                } else if (lowerExists && !upperExists) {
                    sobj.delete(lower, true);
                    sobj.set(upper, lowerValue, CALLSITE_STRICT);
                }
            }
            return sobj;
        } catch (final ClassCastException | NullPointerException e) {
            throw typeError("not.an.object", ScriptRuntime.safeToString(self));
        }
    }

    
ECMA 15.4.4.9 Array.prototype.shift ()
Params:
self – self reference
Returns:
shifted array/**
     * ECMA 15.4.4.9 Array.prototype.shift ()
     *
     * @param self self reference
     * @return shifted array
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE)
    public static Object shift(final Object self) {
        final Object obj = Global.toObject(self);

        Object first = ScriptRuntime.UNDEFINED;

        if (!(obj instanceof ScriptObject)) {
            return first;
        }

        final ScriptObject sobj   = (ScriptObject) obj;

        long len = JSType.toUint32(sobj.getLength());

        if (len > 0) {
            first = sobj.get(0);

            if (bulkable(sobj)) {
                sobj.getArray().shiftLeft(1);
            } else {
                boolean hasPrevious = true;
                for (long k = 1; k < len; k++) {
                    final boolean hasCurrent = sobj.has(k);
                    if (hasCurrent) {
                        sobj.set(k - 1, sobj.get(k), CALLSITE_STRICT);
                    } else if (hasPrevious) {
                        sobj.delete(k - 1, true);
                    }
                    hasPrevious = hasCurrent;
                }
            }
            sobj.delete(--len, true);
        } else {
            len = 0;
        }

        sobj.set("length", len, CALLSITE_STRICT);

        return first;
    }

    
ECMA 15.4.4.10 Array.prototype.slice ( start [ , end ] )
Params:
self –  self reference
start – start of slice (inclusive)
end –   end of slice (optional, exclusive)
Returns:
sliced array/**
     * ECMA 15.4.4.10 Array.prototype.slice ( start [ , end ] )
     *
     * @param self  self reference
     * @param start start of slice (inclusive)
     * @param end   end of slice (optional, exclusive)
     * @return sliced array
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE)
    public static Object slice(final Object self, final Object start, final Object end) {
        final Object       obj                 = Global.toObject(self);
        if (!(obj instanceof ScriptObject)) {
            return ScriptRuntime.UNDEFINED;
        }

        final ScriptObject sobj                = (ScriptObject)obj;
        final long         len                 = JSType.toUint32(sobj.getLength());
        final long         relativeStart       = JSType.toLong(start);
        final long         relativeEnd         = end == ScriptRuntime.UNDEFINED ? len : JSType.toLong(end);

        long k = relativeStart < 0 ? Math.max(len + relativeStart, 0) : Math.min(relativeStart, len);
        final long finale = relativeEnd < 0 ? Math.max(len + relativeEnd, 0) : Math.min(relativeEnd, len);

        if (k >= finale) {
            return new NativeArray(0);
        }

        if (bulkable(sobj)) {
            return new NativeArray(sobj.getArray().slice(k, finale));
        }

        // Construct array with proper length to have a deleted filter on undefined elements
        final NativeArray copy = new NativeArray(finale - k);
        for (long n = 0; k < finale; n++, k++) {
            if (sobj.has(k)) {
                copy.defineOwnProperty(ArrayIndex.getArrayIndex(n), sobj.get(k));
            }
        }

        return copy;
    }

    private static Object compareFunction(final Object comparefn) {
        if (comparefn == ScriptRuntime.UNDEFINED) {
            return null;
        }

        if (!Bootstrap.isCallable(comparefn)) {
            throw typeError("not.a.function", ScriptRuntime.safeToString(comparefn));
        }

        return comparefn;
    }

    private static Object[] sort(final Object[] array, final Object comparefn) {
        final Object cmp = compareFunction(comparefn);

        final List<Object> list = Arrays.asList(array);
        final Object cmpThis = cmp == null || Bootstrap.isStrictCallable(cmp) ? ScriptRuntime.UNDEFINED : Global.instance();

        try {
            Collections.sort(list, new Comparator<Object>() {
                private final MethodHandle call_cmp = getCALL_CMP();
                @Override
                public int compare(final Object x, final Object y) {
                    if (x == ScriptRuntime.UNDEFINED && y == ScriptRuntime.UNDEFINED) {
                        return 0;
                    } else if (x == ScriptRuntime.UNDEFINED) {
                        return 1;
                    } else if (y == ScriptRuntime.UNDEFINED) {
                        return -1;
                    }

                    if (cmp != null) {
                        try {
                            return (int)Math.signum((double)call_cmp.invokeExact(cmp, cmpThis, x, y));
                        } catch (final RuntimeException | Error e) {
                            throw e;
                        } catch (final Throwable t) {
                            throw new RuntimeException(t);
                        }
                    }

                    return JSType.toString(x).compareTo(JSType.toString(y));
                }
            });
        } catch (final IllegalArgumentException iae) {
            // Collections.sort throws IllegalArgumentException when
            // Comparison method violates its general contract

            // See ECMA spec 15.4.4.11 Array.prototype.sort (comparefn).
            // If "comparefn" is not undefined and is not a consistent
            // comparison function for the elements of this array, the
            // behaviour of sort is implementation-defined.
        }

        return list.toArray(new Object[0]);
    }

    
ECMA 15.4.4.11 Array.prototype.sort ( comparefn )
Params:
self –       self reference
comparefn –  element comparison function
Returns:
sorted array/**
     * ECMA 15.4.4.11 Array.prototype.sort ( comparefn )
     *
     * @param self       self reference
     * @param comparefn  element comparison function
     * @return sorted array
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE)
    public static ScriptObject sort(final Object self, final Object comparefn) {
        try {
            final ScriptObject sobj    = (ScriptObject) self;
            final long         len     = JSType.toUint32(sobj.getLength());
            ArrayData          array   = sobj.getArray();

            if (len > 1) {
                // Get only non-missing elements. Missing elements go at the end
                // of the sorted array. So, just don't copy these to sort input.
                final ArrayList<Object> src = new ArrayList<>();

                for (final Iterator<Long> iter = array.indexIterator(); iter.hasNext(); ) {
                    final long index = iter.next();
                    if (index >= len) {
                        break;
                    }
                    src.add(array.getObject((int)index));
                }

                final Object[] sorted = sort(src.toArray(), comparefn);

                for (int i = 0; i < sorted.length; i++) {
                    array = array.set(i, sorted[i], true);
                }

                // delete missing elements - which are at the end of sorted array
                if (sorted.length != len) {
                    array = array.delete(sorted.length, len - 1);
                }

                sobj.setArray(array);
            }

            return sobj;
        } catch (final ClassCastException | NullPointerException e) {
            throw typeError("not.an.object", ScriptRuntime.safeToString(self));
        }
    }

    
ECMA 15.4.4.12 Array.prototype.splice ( start, deleteCount [ item1 [ , item2 [ , ... ] ] ] )
Params:
self – self reference
args – arguments
Returns:
result of splice/**
     * ECMA 15.4.4.12 Array.prototype.splice ( start, deleteCount [ item1 [ , item2 [ , ... ] ] ] )
     *
     * @param self self reference
     * @param args arguments
     * @return result of splice
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 2)
    public static Object splice(final Object self, final Object... args) {
        final Object obj = Global.toObject(self);

        if (!(obj instanceof ScriptObject)) {
            return ScriptRuntime.UNDEFINED;
        }

        final ScriptObject sobj          = (ScriptObject)obj;
        final long         len           = JSType.toUint32(sobj.getLength());
        final long         relativeStart = JSType.toLong(args.length > 0 ? args[0] : ScriptRuntime.UNDEFINED);

        final long actualStart = relativeStart < 0 ? Math.max(len + relativeStart, 0) : Math.min(relativeStart, len);
        final long actualDeleteCount;
        Object[] items = ScriptRuntime.EMPTY_ARRAY;

        if (args.length == 0) {
            actualDeleteCount = 0;
        } else if (args.length == 1) {
            actualDeleteCount = len - actualStart;
        } else {
            actualDeleteCount = Math.min(Math.max(JSType.toLong(args[1]), 0), len - actualStart);
            if (args.length > 2) {
                items = new Object[args.length - 2];
                System.arraycopy(args, 2, items, 0, items.length);
            }
        }

        NativeArray returnValue;

        if (actualStart <= Integer.MAX_VALUE && actualDeleteCount <= Integer.MAX_VALUE && bulkable(sobj)) {
            try {
                returnValue = new NativeArray(sobj.getArray().fastSplice((int)actualStart, (int)actualDeleteCount, items.length));

                // Since this is a dense bulkable array we can use faster defineOwnProperty to copy new elements
                int k = (int) actualStart;
                for (int i = 0; i < items.length; i++, k++) {
                    sobj.defineOwnProperty(k, items[i]);
                }
            } catch (final UnsupportedOperationException uoe) {
                returnValue = slowSplice(sobj, actualStart, actualDeleteCount, items, len);
            }
        } else {
            returnValue = slowSplice(sobj, actualStart, actualDeleteCount, items, len);
        }

        return returnValue;
    }

    private static NativeArray slowSplice(final ScriptObject sobj, final long start, final long deleteCount, final Object[] items, final long len) {

        final NativeArray array = new NativeArray(deleteCount);

        for (long k = 0; k < deleteCount; k++) {
            final long from = start + k;

            if (sobj.has(from)) {
                array.defineOwnProperty(ArrayIndex.getArrayIndex(k), sobj.get(from));
            }
        }

        if (items.length < deleteCount) {
            for (long k = start; k < len - deleteCount; k++) {
                final long from = k + deleteCount;
                final long to   = k + items.length;

                if (sobj.has(from)) {
                    sobj.set(to, sobj.get(from), CALLSITE_STRICT);
                } else {
                    sobj.delete(to, true);
                }
            }

            for (long k = len; k > len - deleteCount + items.length; k--) {
                sobj.delete(k - 1, true);
            }
        } else if (items.length > deleteCount) {
            for (long k = len - deleteCount; k > start; k--) {
                final long from = k + deleteCount - 1;
                final long to   = k + items.length - 1;

                if (sobj.has(from)) {
                    final Object fromValue = sobj.get(from);
                    sobj.set(to, fromValue, CALLSITE_STRICT);
                } else {
                    sobj.delete(to, true);
                }
            }
        }

        long k = start;
        for (int i = 0; i < items.length; i++, k++) {
            sobj.set(k, items[i], CALLSITE_STRICT);
        }

        final long newLength = len - deleteCount + items.length;
        sobj.set("length", newLength, CALLSITE_STRICT);

        return array;
    }

    
ECMA 15.4.4.13 Array.prototype.unshift ( [ item1 [ , item2 [ , ... ] ] ] )
Params:
self –  self reference
items – items for unshift
Returns:
unshifted array/**
     * ECMA 15.4.4.13 Array.prototype.unshift ( [ item1 [ , item2 [ , ... ] ] ] )
     *
     * @param self  self reference
     * @param items items for unshift
     * @return unshifted array
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1)
    public static Object unshift(final Object self, final Object... items) {
        final Object obj = Global.toObject(self);

        if (!(obj instanceof ScriptObject)) {
            return ScriptRuntime.UNDEFINED;
        }

        final ScriptObject sobj   = (ScriptObject)obj;
        final long         len    = JSType.toUint32(sobj.getLength());

        if (items == null) {
            return ScriptRuntime.UNDEFINED;
        }

        if (bulkable(sobj)) {
            sobj.getArray().shiftRight(items.length);

            for (int j = 0; j < items.length; j++) {
                sobj.setArray(sobj.getArray().set(j, items[j], true));
            }
        } else {
            for (long k = len; k > 0; k--) {
                final long from = k - 1;
                final long to = k + items.length - 1;

                if (sobj.has(from)) {
                    final Object fromValue = sobj.get(from);
                    sobj.set(to, fromValue, CALLSITE_STRICT);
                } else {
                    sobj.delete(to, true);
                }
            }

            for (int j = 0; j < items.length; j++) {
                sobj.set(j, items[j], CALLSITE_STRICT);
            }
        }

        final long newLength = len + items.length;
        sobj.set("length", newLength, CALLSITE_STRICT);

        return JSType.toNarrowestNumber(newLength);
    }

    
ECMA 15.4.4.14 Array.prototype.indexOf ( searchElement [ , fromIndex ] )
Params:
self –           self reference
searchElement –  element to search for
fromIndex –      start index of search
Returns:
index of element, or -1 if not found/**
     * ECMA 15.4.4.14 Array.prototype.indexOf ( searchElement [ , fromIndex ] )
     *
     * @param self           self reference
     * @param searchElement  element to search for
     * @param fromIndex      start index of search
     * @return index of element, or -1 if not found
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1)
    public static double indexOf(final Object self, final Object searchElement, final Object fromIndex) {
        try {
            final ScriptObject sobj = (ScriptObject)Global.toObject(self);
            final long         len  = JSType.toUint32(sobj.getLength());
            if (len == 0) {
                return -1;
            }

            final long         n = JSType.toLong(fromIndex);
            if (n >= len) {
                return -1;
            }


            for (long k = Math.max(0, n < 0 ? len - Math.abs(n) : n); k < len; k++) {
                if (sobj.has(k)) {
                    if (ScriptRuntime.EQ_STRICT(sobj.get(k), searchElement)) {
                        return k;
                    }
                }
            }
        } catch (final ClassCastException | NullPointerException e) {
            //fallthru
        }

        return -1;
    }

    
ECMA 15.4.4.15 Array.prototype.lastIndexOf ( searchElement [ , fromIndex ] )
Params:
self – self reference
args – arguments: element to search for and optional from index
Returns:
index of element, or -1 if not found/**
     * ECMA 15.4.4.15 Array.prototype.lastIndexOf ( searchElement [ , fromIndex ] )
     *
     * @param self self reference
     * @param args arguments: element to search for and optional from index
     * @return index of element, or -1 if not found
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1)
    public static double lastIndexOf(final Object self, final Object... args) {
        try {
            final ScriptObject sobj = (ScriptObject)Global.toObject(self);
            final long         len  = JSType.toUint32(sobj.getLength());

            if (len == 0) {
                return -1;
            }

            final Object searchElement = args.length > 0 ? args[0] : ScriptRuntime.UNDEFINED;
            final long   n             = args.length > 1 ? JSType.toLong(args[1]) : len - 1;

            for (long k = n < 0 ? len - Math.abs(n) : Math.min(n, len - 1); k >= 0; k--) {
                if (sobj.has(k)) {
                    if (ScriptRuntime.EQ_STRICT(sobj.get(k), searchElement)) {
                        return k;
                    }
                }
            }
        } catch (final ClassCastException | NullPointerException e) {
            throw typeError("not.an.object", ScriptRuntime.safeToString(self));
        }

        return -1;
    }

    
ECMA 15.4.4.16 Array.prototype.every ( callbackfn [ , thisArg ] )
Params:
self –        self reference
callbackfn –  callback function per element
thisArg –     this argument
Returns:
true if callback function return true for every element in the array, false otherwise/**
     * ECMA 15.4.4.16 Array.prototype.every ( callbackfn [ , thisArg ] )
     *
     * @param self        self reference
     * @param callbackfn  callback function per element
     * @param thisArg     this argument
     * @return true if callback function return true for every element in the array, false otherwise
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1)
    public static boolean every(final Object self, final Object callbackfn, final Object thisArg) {
        return applyEvery(Global.toObject(self), callbackfn, thisArg);
    }

    private static boolean applyEvery(final Object self, final Object callbackfn, final Object thisArg) {
        return new IteratorAction<Boolean>(Global.toObject(self), callbackfn, thisArg, true) {
            private final MethodHandle everyInvoker = getEVERY_CALLBACK_INVOKER();

            @Override
            protected boolean forEach(final Object val, final double i) throws Throwable {
                return result = (boolean)everyInvoker.invokeExact(callbackfn, thisArg, val, i, self);
            }
        }.apply();
    }

    
ECMA 15.4.4.17 Array.prototype.some ( callbackfn [ , thisArg ] )
Params:
self –        self reference
callbackfn –  callback function per element
thisArg –     this argument
Returns:
true if callback function returned true for any element in the array, false otherwise/**
     * ECMA 15.4.4.17 Array.prototype.some ( callbackfn [ , thisArg ] )
     *
     * @param self        self reference
     * @param callbackfn  callback function per element
     * @param thisArg     this argument
     * @return true if callback function returned true for any element in the array, false otherwise
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1)
    public static boolean some(final Object self, final Object callbackfn, final Object thisArg) {
        return new IteratorAction<Boolean>(Global.toObject(self), callbackfn, thisArg, false) {
            private final MethodHandle someInvoker = getSOME_CALLBACK_INVOKER();

            @Override
            protected boolean forEach(final Object val, final double i) throws Throwable {
                return !(result = (boolean)someInvoker.invokeExact(callbackfn, thisArg, val, i, self));
            }
        }.apply();
    }

    
ECMA 15.4.4.18 Array.prototype.forEach ( callbackfn [ , thisArg ] )
Params:
self –        self reference
callbackfn –  callback function per element
thisArg –     this argument
Returns:
undefined/**
     * ECMA 15.4.4.18 Array.prototype.forEach ( callbackfn [ , thisArg ] )
     *
     * @param self        self reference
     * @param callbackfn  callback function per element
     * @param thisArg     this argument
     * @return undefined
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1)
    public static Object forEach(final Object self, final Object callbackfn, final Object thisArg) {
        return new IteratorAction<Object>(Global.toObject(self), callbackfn, thisArg, ScriptRuntime.UNDEFINED) {
            private final MethodHandle forEachInvoker = getFOREACH_CALLBACK_INVOKER();

            @Override
            protected boolean forEach(final Object val, final double i) throws Throwable {
                forEachInvoker.invokeExact(callbackfn, thisArg, val, i, self);
                return true;
            }
        }.apply();
    }

    
ECMA 15.4.4.19 Array.prototype.map ( callbackfn [ , thisArg ] )
Params:
self –        self reference
callbackfn –  callback function per element
thisArg –     this argument
Returns:
array with elements transformed by map function/**
     * ECMA 15.4.4.19 Array.prototype.map ( callbackfn [ , thisArg ] )
     *
     * @param self        self reference
     * @param callbackfn  callback function per element
     * @param thisArg     this argument
     * @return array with elements transformed by map function
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1)
    public static NativeArray map(final Object self, final Object callbackfn, final Object thisArg) {
        return new IteratorAction<NativeArray>(Global.toObject(self), callbackfn, thisArg, null) {
            private final MethodHandle mapInvoker = getMAP_CALLBACK_INVOKER();

            @Override
            protected boolean forEach(final Object val, final double i) throws Throwable {
                final Object r = mapInvoker.invokeExact(callbackfn, thisArg, val, i, self);
                result.defineOwnProperty(ArrayIndex.getArrayIndex(index), r);
                return true;
            }

            @Override
            public void applyLoopBegin(final ArrayLikeIterator<Object> iter0) {
                // map return array should be of same length as source array
                // even if callback reduces source array length
                result = new NativeArray(iter0.getLength());
            }
        }.apply();
    }

    
ECMA 15.4.4.20 Array.prototype.filter ( callbackfn [ , thisArg ] )
Params:
self –        self reference
callbackfn –  callback function per element
thisArg –     this argument
Returns:
filtered array/**
     * ECMA 15.4.4.20 Array.prototype.filter ( callbackfn [ , thisArg ] )
     *
     * @param self        self reference
     * @param callbackfn  callback function per element
     * @param thisArg     this argument
     * @return filtered array
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1)
    public static NativeArray filter(final Object self, final Object callbackfn, final Object thisArg) {
        return new IteratorAction<NativeArray>(Global.toObject(self), callbackfn, thisArg, new NativeArray()) {
            private long to = 0;
            private final MethodHandle filterInvoker = getFILTER_CALLBACK_INVOKER();

            @Override
            protected boolean forEach(final Object val, final double i) throws Throwable {
                if ((boolean)filterInvoker.invokeExact(callbackfn, thisArg, val, i, self)) {
                    result.defineOwnProperty(ArrayIndex.getArrayIndex(to++), val);
                }
                return true;
            }
        }.apply();
    }

    private static Object reduceInner(final ArrayLikeIterator<Object> iter, final Object self, final Object... args) {
        final Object  callbackfn          = args.length > 0 ? args[0] : ScriptRuntime.UNDEFINED;
        final boolean initialValuePresent = args.length > 1;

        Object initialValue = initialValuePresent ? args[1] : ScriptRuntime.UNDEFINED;

        if (callbackfn == ScriptRuntime.UNDEFINED) {
            throw typeError("not.a.function", "undefined");
        }

        if (!initialValuePresent) {
            if (iter.hasNext()) {
                initialValue = iter.next();
            } else {
                throw typeError("array.reduce.invalid.init");
            }
        }

        //if initial value is ScriptRuntime.UNDEFINED - step forward once.
        return new IteratorAction<Object>(Global.toObject(self), callbackfn, ScriptRuntime.UNDEFINED, initialValue, iter) {
            private final MethodHandle reduceInvoker = getREDUCE_CALLBACK_INVOKER();

            @Override
            protected boolean forEach(final Object val, final double i) throws Throwable {
                // TODO: why can't I declare the second arg as Undefined.class?
                result = reduceInvoker.invokeExact(callbackfn, ScriptRuntime.UNDEFINED, result, val, i, self);
                return true;
            }
        }.apply();
    }

    
ECMA 15.4.4.21 Array.prototype.reduce ( callbackfn [ , initialValue ] )
Params:
self – self reference
args – arguments to reduce
Returns:
accumulated result/**
     * ECMA 15.4.4.21 Array.prototype.reduce ( callbackfn [ , initialValue ] )
     *
     * @param self self reference
     * @param args arguments to reduce
     * @return accumulated result
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1)
    public static Object reduce(final Object self, final Object... args) {
        return reduceInner(arrayLikeIterator(self), self, args);
    }

    
ECMA 15.4.4.22 Array.prototype.reduceRight ( callbackfn [ , initialValue ] )
Params:
self –        self reference
args – arguments to reduce
Returns:
accumulated result/**
     * ECMA 15.4.4.22 Array.prototype.reduceRight ( callbackfn [ , initialValue ] )
     *
     * @param self        self reference
     * @param args arguments to reduce
     * @return accumulated result
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, arity = 1)
    public static Object reduceRight(final Object self, final Object... args) {
        return reduceInner(reverseArrayLikeIterator(self), self, args);
    }

    
ECMA6 22.1.3.4 Array.prototype.entries ( )
Params:
self – the self reference
Returns:
an iterator over the array's entries/**
     * ECMA6 22.1.3.4 Array.prototype.entries ( )
     *
     * @param self the self reference
     * @return an iterator over the array's entries
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE)
    public static Object entries(final Object self) {
        return ArrayIterator.newArrayKeyValueIterator(self);
    }

    
ECMA6 22.1.3.13 Array.prototype.keys ( )
Params:
self – the self reference
Returns:
an iterator over the array's keys/**
     * ECMA6 22.1.3.13 Array.prototype.keys ( )
     *
     * @param self the self reference
     * @return an iterator over the array's keys
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE)
    public static Object keys(final Object self) {
        return ArrayIterator.newArrayKeyIterator(self);
    }

    
ECMA6 22.1.3.29 Array.prototype.values ( )
Params:
self – the self reference
Returns:
an iterator over the array's values/**
     * ECMA6 22.1.3.29 Array.prototype.values ( )
     *
     * @param self the self reference
     * @return an iterator over the array's values
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE)
    public static Object values(final Object self) {
        return ArrayIterator.newArrayValueIterator(self);
    }

    
22.1.3.30 Array.prototype [ @@iterator ] ( )
Params:
self – the self reference
Returns:
an iterator over the array's values/**
     * 22.1.3.30 Array.prototype [ @@iterator ] ( )
     *
     * @param self the self reference
     * @return an iterator over the array's values
     */
    @Function(attributes = Attribute.NOT_ENUMERABLE, name = "@@iterator")
    public static Object getIterator(final Object self) {
        return ArrayIterator.newArrayValueIterator(self);
    }

    
Determine if Java bulk array operations may be used on the underlying
storage. This is possible only if the object's prototype chain is empty
or each of the prototypes in the chain is empty.
Params:
self – the object to examine
Returns:
true if optimizable/**
     * Determine if Java bulk array operations may be used on the underlying
     * storage. This is possible only if the object's prototype chain is empty
     * or each of the prototypes in the chain is empty.
     *
     * @param self the object to examine
     * @return true if optimizable
     */
    private static boolean bulkable(final ScriptObject self) {
        return self.isArray() && !hasInheritedArrayEntries(self) && !self.isLengthNotWritable();
    }

    private static boolean hasInheritedArrayEntries(final ScriptObject self) {
        ScriptObject proto = self.getProto();
        while (proto != null) {
            if (proto.hasArrayEntries()) {
                return true;
            }
            proto = proto.getProto();
        }

        return false;
    }

    @Override
    public String toString() {
        return "NativeArray@" + Debug.id(this) + " [" + getArray().getClass().getSimpleName() + ']';
    }

    @Override
    public SpecializedFunction.LinkLogic getLinkLogic(final Class<? extends LinkLogic> clazz) {
        if (clazz == PushLinkLogic.class) {
            return PushLinkLogic.INSTANCE;
        } else if (clazz == PopLinkLogic.class) {
            return PopLinkLogic.INSTANCE;
        } else if (clazz == ConcatLinkLogic.class) {
            return ConcatLinkLogic.INSTANCE;
        }
        return null;
    }

    @Override
    public boolean hasPerInstanceAssumptions() {
        return true; //length writable switchpoint
    }

    
This is an abstract super class that contains common functionality for all
specialized optimistic builtins in NativeArray. For example, it handles the
modification switchpoint which is touched when length is written.
/**
     * This is an abstract super class that contains common functionality for all
     * specialized optimistic builtins in NativeArray. For example, it handles the
     * modification switchpoint which is touched when length is written.
     */
    private static abstract class ArrayLinkLogic extends SpecializedFunction.LinkLogic {
        protected ArrayLinkLogic() {
        }

        protected static ContinuousArrayData getContinuousArrayData(final Object self) {
            try {
                //cast to NativeArray, to avoid cases like x = {0:0, 1:1}, x.length = 2, where we can't use the array push/pop
                return (ContinuousArrayData)((NativeArray)self).getArray();
            } catch (final Exception e) {
                return null;
            }
        }

        
Push and pop callsites can throw ClassCastException as a mechanism to have them
relinked - this enabled fast checks of the kind of ((IntArrayData)arrayData).push(x)
for an IntArrayData only push - if this fails, a CCE will be thrown and we will relink
/**
         * Push and pop callsites can throw ClassCastException as a mechanism to have them
         * relinked - this enabled fast checks of the kind of ((IntArrayData)arrayData).push(x)
         * for an IntArrayData only push - if this fails, a CCE will be thrown and we will relink
         */
        @Override
        public Class<? extends Throwable> getRelinkException() {
            return ClassCastException.class;
        }
    }

    
This is linker logic for optimistic concatenations
/**
     * This is linker logic for optimistic concatenations
     */
    private static final class ConcatLinkLogic extends ArrayLinkLogic {
        private static final LinkLogic INSTANCE = new ConcatLinkLogic();

        @Override
        public boolean canLink(final Object self, final CallSiteDescriptor desc, final LinkRequest request) {
            final Object[] args = request.getArguments();

            if (args.length != 3) { //single argument check
                return false;
            }

            final ContinuousArrayData selfData = getContinuousArrayData(self);
            if (selfData == null) {
                return false;
            }

            final Object arg = args[2];
            // The generic version uses its own logic and ArrayLikeIterator to decide if an object should
            // be iterated over or added as single element. To avoid duplication of code and err on the safe side
            // we only use the specialized version if arg is either a continuous array or a JS primitive.
            if (arg instanceof NativeArray) {
                return (getContinuousArrayData(arg) != null);
            }

            return JSType.isPrimitive(arg);
        }
    }

    
This is linker logic for optimistic pushes
/**
     * This is linker logic for optimistic pushes
     */
    private static final class PushLinkLogic extends ArrayLinkLogic {
        private static final LinkLogic INSTANCE = new PushLinkLogic();

        @Override
        public boolean canLink(final Object self, final CallSiteDescriptor desc, final LinkRequest request) {
            return getContinuousArrayData(self) != null;
        }
    }

    
This is linker logic for optimistic pops
/**
     * This is linker logic for optimistic pops
     */
    private static final class PopLinkLogic extends ArrayLinkLogic {
        private static final LinkLogic INSTANCE = new PopLinkLogic();

        
We need to check if we are dealing with a continuous non empty array data here,
as pop with a primitive return value returns undefined for arrays with length 0
/**
         * We need to check if we are dealing with a continuous non empty array data here,
         * as pop with a primitive return value returns undefined for arrays with length 0
         */
        @Override
        public boolean canLink(final Object self, final CallSiteDescriptor desc, final LinkRequest request) {
            final ContinuousArrayData data = getContinuousNonEmptyArrayData(self);
            if (data != null) {
                final Class<?> elementType = data.getElementType();
                final Class<?> returnType  = desc.getMethodType().returnType();
                final boolean  typeFits    = JSType.getAccessorTypeIndex(returnType) >= JSType.getAccessorTypeIndex(elementType);
                return typeFits;
            }
            return false;
        }

        private static ContinuousArrayData getContinuousNonEmptyArrayData(final Object self) {
            final ContinuousArrayData data = getContinuousArrayData(self);
            if (data != null) {
                return data.length() == 0 ? null : data;
            }
            return null;
        }
    }

    //runtime calls for push and pops. they could be used as guards, but they also perform the runtime logic,
    //so rather than synthesizing them into a guard method handle that would also perform the push on the
    //retrieved receiver, we use this as runtime logic

    //TODO - fold these into the Link logics, but I'll do that as a later step, as I want to do a checkin
    //where everything works first

    private static <T> ContinuousArrayData getContinuousNonEmptyArrayDataCCE(final Object self, final Class<T> clazz) {
        try {
            @SuppressWarnings("unchecked")
            final ContinuousArrayData data = (ContinuousArrayData)(T)((NativeArray)self).getArray();
            if (data.length() != 0L) {
                return data; //if length is 0 we cannot pop and have to relink, because then we'd have to return an undefined, which is a wider type than e.g. int
           }
        } catch (final NullPointerException e) {
            //fallthru
        }
        throw new ClassCastException();
    }

    private static ContinuousArrayData getContinuousArrayDataCCE(final Object self) {
        try {
            return (ContinuousArrayData)((NativeArray)self).getArray();
         } catch (final NullPointerException e) {
             throw new ClassCastException();
         }
    }

    private static ContinuousArrayData getContinuousArrayDataCCE(final Object self, final Class<?> elementType) {
        try {
           return (ContinuousArrayData)((NativeArray)self).getArray(elementType); //ensure element type can fit "elementType"
        } catch (final NullPointerException e) {
            throw new ClassCastException();
        }
    }
}