// todo
private JsValue ParseBoolean(JsValue thisObject, JsValue[] arguments)
{
var inputString = TypeConverter.ToString(arguments.At(0));
var trimmedString = StringPrototype.TrimStartEx(inputString);
if (trimmedString == "true")
{
return(true);
}
if (trimmedString == "false")
{
return(false);
}
throw new JavaScriptException(Engine.RangeError,
string.Format("Invalid string {0}, Convert to boolean faild!", trimmedString));
}
/// <summary>
/// http://www.ecma-international.org/ecma-262/5.1/#sec-15.1.2.3
/// </summary>
public static JsValue ParseFloat(JsValue thisObject, JsValue[] arguments)
{
var inputString = TypeConverter.ToString(arguments.At(0));
var trimmedString = StringPrototype.TrimStartEx(inputString);
var sign = 1;
if (trimmedString.Length > 0)
{
if (trimmedString[0] == '-')
{
sign = -1;
trimmedString = trimmedString.Substring(1);
}
else if (trimmedString[0] == '+')
{
trimmedString = trimmedString.Substring(1);
}
}
if (trimmedString.StartsWith("Infinity"))
{
return(sign * double.PositiveInfinity);
}
if (trimmedString.StartsWith("NaN"))
{
return(double.NaN);
}
var separator = (char)0;
bool isNan = true;
decimal number = 0;
var i = 0;
for (; i < trimmedString.Length; i++)
{
var c = trimmedString[i];
if (c == '.')
{
i++;
separator = '.';
break;
}
if (c == 'e' || c == 'E')
{
i++;
separator = 'e';
break;
}
var digit = c - '0';
if (digit >= 0 && digit <= 9)
{
isNan = false;
number = number * 10 + digit;
}
else
{
break;
}
}
decimal pow = 0.1m;
if (separator == '.')
{
for (; i < trimmedString.Length; i++)
{
var c = trimmedString[i];
var digit = c - '0';
if (digit >= 0 && digit <= 9)
{
isNan = false;
number += digit * pow;
pow *= 0.1m;
}
else if (c == 'e' || c == 'E')
{
i++;
separator = 'e';
break;
}
else
{
break;
}
}
}
var exp = 0;
var expSign = 1;
if (separator == 'e')
{
if (i < trimmedString.Length)
{
if (trimmedString[i] == '-')
{
expSign = -1;
i++;
}
else if (trimmedString[i] == '+')
{
i++;
}
}
for (; i < trimmedString.Length; i++)
{
var c = trimmedString[i];
var digit = c - '0';
if (digit >= 0 && digit <= 9)
{
exp = exp * 10 + digit;
}
else
{
break;
}
}
}
if (isNan)
{
return(double.NaN);
}
for (var k = 1; k <= exp; k++)
{
if (expSign > 0)
{
number *= 10;
}
else
{
number /= 10;
}
}
return((double)(sign * number));
}
