1 /*
   2  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.nashorn.internal.objects;
  27 
  28 import static jdk.nashorn.internal.lookup.Lookup.MH;
  29 import static jdk.nashorn.internal.runtime.ECMAErrors.rangeError;
  30 import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
  31 import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;
  32 
  33 import java.lang.invoke.MethodHandle;
  34 import java.lang.invoke.MethodHandles;
  35 import java.lang.invoke.MethodType;
  36 import java.util.Locale;
  37 import jdk.dynalink.linker.GuardedInvocation;
  38 import jdk.dynalink.linker.LinkRequest;
  39 import jdk.nashorn.internal.objects.annotations.Attribute;
  40 import jdk.nashorn.internal.objects.annotations.Constructor;
  41 import jdk.nashorn.internal.objects.annotations.Function;
  42 import jdk.nashorn.internal.objects.annotations.Property;
  43 import jdk.nashorn.internal.objects.annotations.ScriptClass;
  44 import jdk.nashorn.internal.objects.annotations.SpecializedFunction;
  45 import jdk.nashorn.internal.objects.annotations.Where;
  46 import jdk.nashorn.internal.runtime.JSType;
  47 import jdk.nashorn.internal.runtime.PropertyMap;
  48 import jdk.nashorn.internal.runtime.ScriptObject;
  49 import jdk.nashorn.internal.runtime.ScriptRuntime;
  50 import jdk.nashorn.internal.runtime.doubleconv.DoubleConversion;
  51 import jdk.nashorn.internal.runtime.linker.NashornGuards;
  52 import jdk.nashorn.internal.runtime.linker.PrimitiveLookup;
  53 
  54 /**
  55  * ECMA 15.7 Number Objects.
  56  *
  57  */
  58 @ScriptClass("Number")
  59 public final class NativeNumber extends ScriptObject {
  60 
  61     /** Method handle to create an object wrapper for a primitive number. */
  62     static final MethodHandle WRAPFILTER = findOwnMH("wrapFilter", MH.type(NativeNumber.class, Object.class));
  63     /** Method handle to retrieve the Number prototype object. */
  64     private static final MethodHandle PROTOFILTER = findOwnMH("protoFilter", MH.type(Object.class, Object.class));
  65 
  66     /** ECMA 15.7.3.2 largest positive finite value */
  67     @Property(attributes = Attribute.NON_ENUMERABLE_CONSTANT, where = Where.CONSTRUCTOR)
  68     public static final double MAX_VALUE = Double.MAX_VALUE;
  69 
  70     /** ECMA 15.7.3.3 smallest positive finite value */
  71     @Property(attributes = Attribute.NON_ENUMERABLE_CONSTANT, where = Where.CONSTRUCTOR)
  72     public static final double MIN_VALUE = Double.MIN_VALUE;
  73 
  74     /** ECMA 15.7.3.4 NaN */
  75     @Property(attributes = Attribute.NON_ENUMERABLE_CONSTANT, where = Where.CONSTRUCTOR)
  76     public static final double NaN = Double.NaN;
  77 
  78     /** ECMA 15.7.3.5 negative infinity */
  79     @Property(attributes = Attribute.NON_ENUMERABLE_CONSTANT, where = Where.CONSTRUCTOR)
  80     public static final double NEGATIVE_INFINITY = Double.NEGATIVE_INFINITY;
  81 
  82     /** ECMA 15.7.3.5 positive infinity */
  83     @Property(attributes = Attribute.NON_ENUMERABLE_CONSTANT, where = Where.CONSTRUCTOR)
  84     public static final double POSITIVE_INFINITY = Double.POSITIVE_INFINITY;
  85 
  86     private final double  value;
  87 
  88     // initialized by nasgen
  89     private static PropertyMap $nasgenmap$;
  90 
  91     private NativeNumber(final double value, final ScriptObject proto, final PropertyMap map) {
  92         super(proto, map);
  93         this.value = value;
  94     }
  95 
  96     NativeNumber(final double value, final Global global) {
  97         this(value, global.getNumberPrototype(), $nasgenmap$);
  98     }
  99 
 100     private NativeNumber(final double value) {
 101         this(value, Global.instance());
 102     }
 103 
 104 
 105     @Override
 106     public String safeToString() {
 107         return "[Number " + toString() + "]";
 108     }
 109 
 110     @Override
 111     public String toString() {
 112         return Double.toString(getValue());
 113     }
 114 
 115     /**
 116      * Get the value of this Number
 117      * @return a {@code double} representing the Number value
 118      */
 119     public double getValue() {
 120         return doubleValue();
 121     }
 122 
 123     /**
 124      * Get the value of this Number
 125      * @return a {@code double} representing the Number value
 126      */
 127     public double doubleValue() {
 128         return value;
 129     }
 130 
 131     @Override
 132     public String getClassName() {
 133         return "Number";
 134     }
 135 
 136     /**
 137      * ECMA 15.7.2 - The Number constructor
 138      *
 139      * @param newObj is this Number instantiated with the new operator
 140      * @param self   self reference
 141      * @param args   value of number
 142      * @return the Number instance (internally represented as a {@code NativeNumber})
 143      */
 144     @Constructor(arity = 1)
 145     public static Object constructor(final boolean newObj, final Object self, final Object... args) {
 146         final double num = (args.length > 0) ? JSType.toNumber(args[0]) : 0.0;
 147 
 148         return newObj? new NativeNumber(num) : num;
 149     }
 150 
 151     /**
 152      * ECMA 15.7.4.5 Number.prototype.toFixed (fractionDigits)
 153      *
 154      * @param self           self reference
 155      * @param fractionDigits how many digits should be after the decimal point, 0 if undefined
 156      *
 157      * @return number in decimal fixed point notation
 158      */
 159     @Function(attributes = Attribute.NOT_ENUMERABLE)
 160     public static String toFixed(final Object self, final Object fractionDigits) {
 161         return toFixed(self, JSType.toInteger(fractionDigits));
 162     }
 163 
 164     /**
 165      * ECMA 15.7.4.5 Number.prototype.toFixed (fractionDigits) specialized for int fractionDigits
 166      *
 167      * @param self           self reference
 168      * @param fractionDigits how many digits should be after the decimal point, 0 if undefined
 169      *
 170      * @return number in decimal fixed point notation
 171      */
 172     @SpecializedFunction
 173     public static String toFixed(final Object self, final int fractionDigits) {
 174         if (fractionDigits < 0 || fractionDigits > 20) {
 175             throw rangeError("invalid.fraction.digits", "toFixed");
 176         }
 177 
 178         final double x = getNumberValue(self);
 179         if (Double.isNaN(x)) {
 180             return "NaN";
 181         }
 182 
 183         if (Math.abs(x) >= 1e21) {
 184             return JSType.toString(x);
 185         }
 186 
 187         return DoubleConversion.toFixed(x, fractionDigits);
 188     }
 189 
 190     /**
 191      * ECMA 15.7.4.6 Number.prototype.toExponential (fractionDigits)
 192      *
 193      * @param self           self reference
 194      * @param fractionDigits how many digital should be after the significand's decimal point. If undefined, use as many as necessary to uniquely specify number.
 195      *
 196      * @return number in decimal exponential notation
 197      */
 198     @Function(attributes = Attribute.NOT_ENUMERABLE)
 199     public static String toExponential(final Object self, final Object fractionDigits) {
 200         final double  x         = getNumberValue(self);
 201         final boolean trimZeros = fractionDigits == UNDEFINED;
 202         final int     f         = trimZeros ? 16 : JSType.toInteger(fractionDigits);
 203 
 204         if (Double.isNaN(x)) {
 205             return "NaN";
 206         } else if (Double.isInfinite(x)) {
 207             return x > 0? "Infinity" : "-Infinity";
 208         }
 209 
 210         if (fractionDigits != UNDEFINED && (f < 0 || f > 20)) {
 211             throw rangeError("invalid.fraction.digits", "toExponential");
 212         }
 213 
 214         final String res = String.format(Locale.US, "%1." + f + "e", x);
 215         return fixExponent(res, trimZeros);
 216     }
 217 
 218     /**
 219      * ECMA 15.7.4.7 Number.prototype.toPrecision (precision)
 220      *
 221      * @param self      self reference
 222      * @param precision use {@code precision - 1} digits after the significand's decimal point or call {@link JSType#toString} if undefined
 223      *
 224      * @return number in decimal exponentiation notation or decimal fixed notation depending on {@code precision}
 225      */
 226     @Function(attributes = Attribute.NOT_ENUMERABLE)
 227     public static String toPrecision(final Object self, final Object precision) {
 228         final double x = getNumberValue(self);
 229         if (precision == UNDEFINED) {
 230             return JSType.toString(x);
 231         }
 232         return (toPrecision(x, JSType.toInteger(precision)));
 233     }
 234 
 235     /**
 236      * ECMA 15.7.4.7 Number.prototype.toPrecision (precision) specialized f
 237      *
 238      * @param self      self reference
 239      * @param precision use {@code precision - 1} digits after the significand's decimal point.
 240      *
 241      * @return number in decimal exponentiation notation or decimal fixed notation depending on {@code precision}
 242      */
 243     @SpecializedFunction
 244     public static String toPrecision(final Object self, final int precision) {
 245         return toPrecision(getNumberValue(self), precision);
 246     }
 247 
 248     private static String toPrecision(final double x, final int p) {
 249         if (Double.isNaN(x)) {
 250             return "NaN";
 251         } else if (Double.isInfinite(x)) {
 252             return x > 0? "Infinity" : "-Infinity";
 253         }
 254 
 255         if (p < 1 || p > 21) {
 256             throw rangeError("invalid.precision");
 257         }
 258 
 259         // workaround for http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6469160
 260         if (x == 0.0 && p <= 1) {
 261             return "0";
 262         }
 263 
 264         return DoubleConversion.toPrecision(x, p);
 265     }
 266 
 267     /**
 268      * ECMA 15.7.4.2 Number.prototype.toString ( [ radix ] )
 269      *
 270      * @param self  self reference
 271      * @param radix radix to use for string conversion
 272      * @return string representation of this Number in the given radix
 273      */
 274     @Function(attributes = Attribute.NOT_ENUMERABLE)
 275     public static String toString(final Object self, final Object radix) {
 276         if (radix != UNDEFINED) {
 277             final int intRadix = JSType.toInteger(radix);
 278             if (intRadix != 10) {
 279                 if (intRadix < 2 || intRadix > 36) {
 280                     throw rangeError("invalid.radix");
 281                 }
 282                 return JSType.toString(getNumberValue(self), intRadix);
 283             }
 284         }
 285 
 286         return JSType.toString(getNumberValue(self));
 287     }
 288 
 289     /**
 290      * ECMA 15.7.4.3 Number.prototype.toLocaleString()
 291      *
 292      * @param self self reference
 293      * @return localized string for this Number
 294      */
 295     @Function(attributes = Attribute.NOT_ENUMERABLE)
 296     public static String toLocaleString(final Object self) {
 297         return JSType.toString(getNumberValue(self));
 298     }
 299 
 300 
 301     /**
 302      * ECMA 15.7.4.4 Number.prototype.valueOf ( )
 303      *
 304      * @param self self reference
 305      * @return number value for this Number
 306      */
 307     @Function(attributes = Attribute.NOT_ENUMERABLE)
 308     public static double valueOf(final Object self) {
 309         return getNumberValue(self);
 310     }
 311 
 312     /**
 313      * Lookup the appropriate method for an invoke dynamic call.
 314      * @param request  The link request
 315      * @param receiver receiver of call
 316      * @return Link to be invoked at call site.
 317      */
 318     public static GuardedInvocation lookupPrimitive(final LinkRequest request, final Object receiver) {
 319         return PrimitiveLookup.lookupPrimitive(request, NashornGuards.getNumberGuard(), new NativeNumber(((Number)receiver).doubleValue()), WRAPFILTER, PROTOFILTER);
 320     }
 321 
 322     @SuppressWarnings("unused")
 323     private static NativeNumber wrapFilter(final Object receiver) {
 324         return new NativeNumber(((Number)receiver).doubleValue());
 325     }
 326 
 327     @SuppressWarnings("unused")
 328     private static Object protoFilter(final Object object) {
 329         return Global.instance().getNumberPrototype();
 330     }
 331 
 332     private static double getNumberValue(final Object self) {
 333         if (self instanceof Number) {
 334             return ((Number)self).doubleValue();
 335         } else if (self instanceof NativeNumber) {
 336             return ((NativeNumber)self).getValue();
 337         } else if (self != null && self == Global.instance().getNumberPrototype()) {
 338             return 0.0;
 339         } else {
 340             throw typeError("not.a.number", ScriptRuntime.safeToString(self));
 341         }
 342     }
 343 
 344     // Exponent of Java "e" or "E" formatter is always 2 digits and zero
 345     // padded if needed (e+01, e+00, e+12 etc.) JS expects exponent to contain
 346     // exact number of digits e+1, e+0, e+12 etc. Fix the exponent here.
 347     //
 348     // Additionally, if trimZeros is true, this cuts trailing zeros in the
 349     // fraction part for calls to toExponential() with undefined fractionDigits
 350     // argument.
 351     private static String fixExponent(final String str, final boolean trimZeros) {
 352         final int index = str.indexOf('e');
 353         if (index < 1) {
 354             // no exponent, do nothing..
 355             return str;
 356         }
 357 
 358         // check if character after e+ or e- is 0
 359         final int expPadding = str.charAt(index + 2) == '0' ? 3 : 2;
 360         // check if there are any trailing zeroes we should remove
 361 
 362         int fractionOffset = index;
 363         if (trimZeros) {
 364             assert fractionOffset > 0;
 365             char c = str.charAt(fractionOffset - 1);
 366             while (fractionOffset > 1 && (c == '0' || c == '.')) {
 367                 c = str.charAt(--fractionOffset - 1);
 368             }
 369 
 370         }
 371         // if anything needs to be done compose a new string
 372         if (fractionOffset < index || expPadding == 3) {
 373             return str.substring(0, fractionOffset)
 374                     + str.substring(index, index + 2)
 375                     + str.substring(index + expPadding);
 376         }
 377         return str;
 378     }
 379 
 380     private static MethodHandle findOwnMH(final String name, final MethodType type) {
 381         return MH.findStatic(MethodHandles.lookup(), NativeNumber.class, name, type);
 382     }
 383 }