number_object.cpp
// -*- c-basic-offset: 2 -*-
/*
* This file is part of the KDE libraries
* Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
* Copyright (C) 2003 Peter Kelly (pmk@post.com)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include "value.h"
#include "object.h"
#include "types.h"
#include "interpreter.h"
#include "operations.h"
#include "number_object.h"
#include "error_object.h"
#include "dtoa.h"
#include "number_object.lut.h"
#include <assert.h>
#include <math.h>
using namespace KJS;
// ------------------------------ NumberInstanceImp ----------------------------
const ClassInfo NumberInstanceImp::info = {"Number", 0, 0, 0};
NumberInstanceImp::NumberInstanceImp(ObjectImp *proto)
: ObjectImp(proto)
{
}
// ------------------------------ NumberPrototypeImp ---------------------------
// ECMA 15.7.4
NumberPrototypeImp::NumberPrototypeImp(ExecState *exec,
ObjectPrototypeImp *objProto,
FunctionPrototypeImp *funcProto)
: NumberInstanceImp(objProto)
{
Value protect(this);
setInternalValue(NumberImp::zero());
// The constructor will be added later, after NumberObjectImp has been constructed
putDirect(toStringPropertyName,new NumberProtoFuncImp(exec,funcProto,NumberProtoFuncImp::ToString,
1,toStringPropertyName),DontEnum);
putDirect(toLocaleStringPropertyName,new NumberProtoFuncImp(exec,funcProto,NumberProtoFuncImp::ToLocaleString,
0,toLocaleStringPropertyName),DontEnum);
putDirect(valueOfPropertyName,new NumberProtoFuncImp(exec,funcProto,NumberProtoFuncImp::ValueOf,
0,valueOfPropertyName),DontEnum);
putDirect("toFixed", new NumberProtoFuncImp(exec,funcProto,NumberProtoFuncImp::ToFixed,
1,"toFixed"),DontEnum);
putDirect("toExponential",new NumberProtoFuncImp(exec,funcProto,NumberProtoFuncImp::ToExponential,
1,"toExponential"),DontEnum);
putDirect("toPrecision",new NumberProtoFuncImp(exec,funcProto,NumberProtoFuncImp::ToPrecision,
1,"toPrecision"),DontEnum);
}
// ------------------------------ NumberProtoFuncImp ---------------------------
NumberProtoFuncImp::NumberProtoFuncImp(ExecState * /*exec*/, FunctionPrototypeImp *funcProto,
int i, int len, const Identifier &_ident)
: InternalFunctionImp(funcProto), id(i)
{
Value protect(this);
putDirect(lengthPropertyName, len, DontDelete|ReadOnly|DontEnum);
ident = _ident;
}
bool NumberProtoFuncImp::implementsCall() const
{
return true;
}
static UString integer_part_noexp(double d)
{
int decimalPoint;
int signDummy;
char *result = kjs_dtoa(d, 0, 0, &decimalPoint, &signDummy, NULL);
int length = strlen(result);
// sign for non-zero, negative numbers
UString str = d < 0 ? "-" : "";
if (decimalPoint == 9999) {
str += UString(result);
} else if (decimalPoint <= 0) {
str += UString("0");
} else {
char *buf;
if (length <= decimalPoint) {
buf = (char*)malloc(decimalPoint+1);
strcpy(buf,result);
memset(buf+length,'0',decimalPoint-length);
} else {
buf = (char*)malloc(decimalPoint+1);
strncpy(buf,result,decimalPoint);
}
buf[decimalPoint] = '\0';
str += UString(buf);
free(buf);
}
kjs_freedtoa(result);
return str;
}
static UString char_sequence(char c, int count)
{
char *buf = (char*)malloc(count+1);
memset(buf,c,count);
buf[count] = '\0';
UString s(buf);
free(buf);
return s;
}
// ECMA 15.7.4.2 - 15.7.4.7
Value NumberProtoFuncImp::call(ExecState *exec, Object &thisObj, const List &args)
{
Value result;
// no generic function. "this" has to be a Number object
KJS_CHECK_THIS( NumberInstanceImp, thisObj );
// execute "toString()" or "valueOf()", respectively
Value v = thisObj.internalValue();
switch (id) {
case ToString: {
int radix = 10;
if (!args.isEmpty() && args[0].type() != UndefinedType)
radix = args[0].toInteger(exec);
if (radix < 2 || radix > 36 || radix == 10)
result = String(v.toString(exec));
else {
const char digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
// INT_MAX results in 1024 characters left of the dot with radix 2
// give the same space on the right side. safety checks are in place
// unless someone finds a precise rule.
char s[2048 + 3];
double x = v.toNumber(exec);
if (isNaN(x) || isInf(x))
return String(UString::from(x));
// apply algorithm on absolute value. add sign later.
bool neg = false;
if (x < 0.0) {
neg = true;
x = -x;
}
// convert integer portion
double f = floor(x);
double d = f;
char *dot = s + sizeof(s) / 2;
char *p = dot;
*p = '\0';
do {
*--p = digits[int(fmod(d, double(radix)))];
d /= radix;
} while ((d <= -1.0 || d >= 1.0) && p > s);
// any decimal fraction ?
d = x - f;
const double eps = 0.001; // TODO: guessed. base on radix ?
if (d < -eps || d > eps) {
*dot++ = '.';
do {
d *= radix;
*dot++ = digits[int(d)];
d -= int(d);
} while ((d < -eps || d > eps) && dot - s < int(sizeof(s)) - 1);
*dot = '\0';
}
// add sign if negative
if (neg)
*--p = '-';
result = String(p);
}
break;
}
case ToLocaleString: /* TODO */
result = String(v.toString(exec));
break;
case ValueOf:
result = Number(v.toNumber(exec));
break;
case ToFixed:
{
// FIXME: firefox works for all values, not just 0..20. This includes
// NaN, infinity, undefined, etc. This is just a hack to pass our regression
// suite.
Value fractionDigits = args[0];
int f = -1;
double fd = fractionDigits.toNumber(exec);
if (isNaN(fd)) {
f = 0;
} else if (!isInf(fd)) {
f = int(fd);
}
if (f < 0 || f > 20) {
Object err = Error::create(exec,RangeError);
exec->setException(err);
return err;
}
double x = v.toNumber(exec);
if (isNaN(x))
return String("NaN");
UString s = "";
if (x < 0) {
s += "-";
x = -x;
}
if (x >= 1e21)
return String(s+UString::from(x));
double n = floor(x*pow(10.0,f));
if (fabs(n/pow(10.0,f)-x) > fabs((n+1)/pow(10.0,f)-x))
n++;
UString m = integer_part_noexp(n);
int k = m.size();
if (k <= f) {
UString z = "";
for (int i = 0; i < f+1-k; i++)
z += "0";
m = z + m;
k = f + 1;
assert(k == m.size());
}
if (k-f < m.size())
return String(s+m.substr(0,k-f)+"."+m.substr(k-f));
else
return String(s+m.substr(0,k-f));
}
case ToExponential: {
double x = v.toNumber(exec);
if (isNaN(x) || isInf(x))
return String(UString::from(x));
int f = 1;
Value fractionDigits = args[0];
if (args.size() > 0) {
f = fractionDigits.toInteger(exec);
if (f < 0 || f > 20) {
Object err = Error::create(exec,RangeError);
exec->setException(err);
return err;
}
}
int decimalAdjust = 0;
if (!fractionDigits.isA(UndefinedType)) {
double logx = floor(log10(fabs(x)));
x /= pow(10.0,logx);
double fx = floor(x*pow(10.0,f))/pow(10.0,f);
double cx = ceil(x*pow(10.0,f))/pow(10.0,f);
if (fabs(fx-x) < fabs(cx-x))
x = fx;
else
x = cx;
decimalAdjust = int(logx);
}
char buf[80];
int decimalPoint;
int sign;
if (isNaN(x))
return String("NaN");
char *result = kjs_dtoa(x, 0, 0, &decimalPoint, &sign, NULL);
int length = strlen(result);
decimalPoint += decimalAdjust;
int i = 0;
if (sign) {
buf[i++] = '-';
}
if (decimalPoint == 999) {
strcpy(buf + i, result);
} else {
buf[i++] = result[0];
if (fractionDigits.isA(UndefinedType))
f = length-1;
if (length > 1 && f > 0) {
buf[i++] = '.';
int haveFDigits = length-1;
if (f < haveFDigits) {
strncpy(buf+i,result+1, f);
i += f;
}
else {
strcpy(buf+i,result+1);
i += length-1;
for (int j = 0; j < f-haveFDigits; j++)
buf[i++] = '0';
}
}
buf[i++] = 'e';
buf[i++] = (decimalPoint >= 0) ? '+' : '-';
// decimalPoint can't be more than 3 digits decimal given the
// nature of float representation
int exponential = decimalPoint - 1;
if (exponential < 0) {
exponential = exponential * -1;
}
if (exponential >= 100) {
buf[i++] = '0' + exponential / 100;
}
if (exponential >= 10) {
buf[i++] = '0' + (exponential % 100) / 10;
}
buf[i++] = '0' + exponential % 10;
buf[i++] = '\0';
}
assert(i <= 80);
kjs_freedtoa(result);
return String(UString(buf));
}
case ToPrecision:
{
int e = 0;
UString m;
int p = args[0].toInteger(exec);
double x = v.toNumber(exec);
if (args[0].isA(UndefinedType) || isNaN(x) || isInf(x))
return String(v.toString(exec));
UString s = "";
if (x < 0) {
s = "-";
x = -x;
}
if (p < 1 || p > 21) {
Object err = Error::create(exec, RangeError,
"toPrecision() argument must be between 1 and 21");
exec->setException(err);
return err;
}
if (x != 0) {
// suggestions for a better algorithm welcome!
e = int(log10(x));
double n = floor(x/pow(10.0,e-p+1));
if (n < pow(10.0,p-1)) {
// first guess was not good
e = e - 1;
n = floor(x/pow(10.0,e-p+1));
if (n >= pow(10.0,p)) {
// violated constraint. try something else.
n = pow(10.0,p-1);
e = int(log10(x/n)) + p - 1;
}
}
if (fabs((n+1)*pow(10.0,e-p+1)-x) < fabs(n*pow(10.0,e-p+1)-x))
n++;
assert(pow(10.0,p-1) <= n);
assert(n < pow(10.0,p));
m = integer_part_noexp(n);
if (e < -6 || e >= p) {
if (m.size() > 1)
m = m.substr(0,1)+"."+m.substr(1);
if (e >= 0)
return String(s+m+"e+"+UString::from(e));
else
return String(s+m+"e-"+UString::from(-e));
}
}
else {
m = char_sequence('0',p);
e = 0;
}
if (e == p-1) {
return String(s+m);
}
else if (e >= 0) {
if (e+1 < m.size())
return String(s+m.substr(0,e+1)+"."+m.substr(e+1));
else
return String(s+m.substr(0,e+1));
}
else {
return String(s+"0."+char_sequence('0',-(e+1))+m);
}
}
}
return result;
}
// ------------------------------ NumberObjectImp ------------------------------
const ClassInfo NumberObjectImp::info = {"Function", &InternalFunctionImp::info, &numberTable, 0};
/* Source for number_object.lut.h
@begin numberTable 5
NaN NumberObjectImp::NaNValue DontEnum|DontDelete|ReadOnly
NEGATIVE_INFINITY NumberObjectImp::NegInfinity DontEnum|DontDelete|ReadOnly
POSITIVE_INFINITY NumberObjectImp::PosInfinity DontEnum|DontDelete|ReadOnly
MAX_VALUE NumberObjectImp::MaxValue DontEnum|DontDelete|ReadOnly
MIN_VALUE NumberObjectImp::MinValue DontEnum|DontDelete|ReadOnly
@end
*/
NumberObjectImp::NumberObjectImp(ExecState * /*exec*/,
FunctionPrototypeImp *funcProto,
NumberPrototypeImp *numberProto)
: InternalFunctionImp(funcProto)
{
Value protect(this);
// Number.Prototype
putDirect(prototypePropertyName, numberProto, DontEnum|DontDelete|ReadOnly);
// no. of arguments for constructor
putDirect(lengthPropertyName, NumberImp::one(), ReadOnly|DontDelete|DontEnum);
}
Value NumberObjectImp::get(ExecState *exec, const Identifier &propertyName) const
{
return lookupGetValue<NumberObjectImp, InternalFunctionImp>( exec, propertyName, &numberTable, this );
}
Value NumberObjectImp::getValueProperty(ExecState *, int token) const
{
// ECMA 15.7.3
switch(token) {
case NaNValue:
return Number(NaN);
case NegInfinity:
return Number(-Inf);
case PosInfinity:
return Number(Inf);
case MaxValue:
return Number(1.7976931348623157E+308);
case MinValue:
return Number(5E-324);
}
return Null();
}
bool NumberObjectImp::implementsConstruct() const
{
return true;
}
// ECMA 15.7.1
Object NumberObjectImp::construct(ExecState *exec, const List &args)
{
ObjectImp *proto = exec->lexicalInterpreter()->builtinNumberPrototype().imp();
Object obj(new NumberInstanceImp(proto));
Number n;
if (args.isEmpty())
n = Number(0);
else
n = args[0].toNumber(exec);
obj.setInternalValue(n);
return obj;
}
bool NumberObjectImp::implementsCall() const
{
return true;
}
// ECMA 15.7.2
Value NumberObjectImp::call(ExecState *exec, Object &/*thisObj*/, const List &args)
{
if (args.isEmpty())
return Number(0);
else
return Number(args[0].toNumber(exec));
}
KJS::Value
Value objects are act as wrappers ("smart pointers") around ValueImp objects and their descendents...
Definition: value.h:168
KJS::UString::substr
UString substr(int pos=0, int len=-1) const
Definition: ustring.cpp:869
KJS::InternalFunctionImp
Base class for all function objects.
Definition: function.h:41
KJS::UString::from
static UString from(int i)
Constructs a string from an int.
Definition: ustring.cpp:341
KJS::UString::size
int size() const
Definition: ustring.h:359
KJS::Number
Represents an primitive Number value.
Definition: value.h:368
KJS::Null
Represents an primitive Null value.
Definition: value.h:295
KJS::ExecState::lexicalInterpreter
Interpreter * lexicalInterpreter() const
Returns the interpreter associated with the current scope's global object.
Definition: interpreter.cpp:395
KJS::Error::create
static Object create(ExecState *exec, ErrorType errtype=GeneralError, const char *message=0, int lineno=-1, int sourceId=-1)
Factory method for error objects.
Definition: object.cpp:504
KJS::FunctionPrototypeImp
The initial value of Function.prototype (and thus all objects created with the Function constructor) ...
Definition: function_object.h:35
KJS::Value::toNumber
double toNumber(ExecState *exec) const
Performs the ToNumber type conversion operation on this value (ECMA 9.3)
Definition: value.h:222
KJS::Object
Represents an Object.
Definition: object.h:82
KJS::Value::isA
bool isA(Type t) const
Checks whether or not the value is of a particular tpye.
Definition: value.h:204
KJS::UString
Unicode string class.
Definition: ustring.h:189
KJS::String
Represents an primitive String value.
Definition: value.h:341
KJS::Object::internalValue
Value internalValue() const
Returns the internal value of the object.
Definition: object.h:718
KJS::List::size
int size() const
Definition: list.h:90
KJS::List
Native list type.
Definition: list.h:48
KJS::Value::toString
UString toString(ExecState *exec) const
Performs the ToString type conversion operation on this value (ECMA 9.8)
Definition: value.h:247
KJS::ClassInfo
Class Information.
Definition: object.h:59
KJS::Interpreter::builtinNumberPrototype
Object builtinNumberPrototype() const
Returns the builtin "Number.prototype" object.
Definition: interpreter.cpp:244
KJS::Value::toInteger
int toInteger(ExecState *exec) const
Performs the ToInteger type conversion operation on this value (ECMA 9.4)
Definition: value.h:227
KJS::List::isEmpty
bool isEmpty() const
Definition: list.h:86
KJS::ExecState
Represents the current state of script execution.
Definition: interpreter.h:439
KJS::Identifier
Represents an Identifier for a Javascript object.
Definition: identifier.h:32

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