/// <summary>
/// http://www.ecma-international.org/ecma-262/5.1/#sec-9.2
/// </summary>
/// <param name="o"></param>
/// <returns></returns>
public static bool ToBoolean(JsValue o)
{
if (o.IsObject())
{
return true;
}
if (o == Undefined.Instance || o == Null.Instance)
{
return false;
}
if (o.IsBoolean())
{
return o.AsBoolean();
}
if (o.IsNumber())
{
var n = o.AsNumber();
if (n.Equals(0) || double.IsNaN(n))
{
return false;
}
else
{
return true;
}
}
if (o.IsString())
{
var s = o.AsString();
if (String.IsNullOrEmpty(s))
{
return false;
}
else
{
return true;
}
}
return true;
}
/// <summary>
/// http://www.ecma-international.org/ecma-262/5.1/#sec-9.8
/// </summary>
/// <param name="o"></param>
/// <returns></returns>
public static string ToString(JsValue o)
{
if (o.IsObject())
{
var p = o.AsObject() as IPrimitiveInstance;
if (p != null)
{
o = p.PrimitiveValue;
}
}
if (o.IsString())
{
return o.AsString();
}
if (o == Undefined.Instance)
{
return Undefined.Text;
}
if (o == Null.Instance)
{
return Null.Text;
}
if (o.IsBoolean())
{
return o.AsBoolean() ? "true" : "false";
}
if (o.IsNumber())
{
return NumberPrototype.ToNumberString(o.AsNumber());
}
return ToString(ToPrimitive(o, Types.String));
}
public static ObjectInstance ToObject(Engine engine, JsValue value)
{
if (value.IsObject())
{
return value.AsObject();
}
if (value == Undefined.Instance)
{
throw new JavaScriptException(engine.TypeError);
}
if (value == Null.Instance)
{
throw new JavaScriptException(engine.TypeError);
}
if (value.IsBoolean())
{
return engine.Boolean.Construct(value.AsBoolean());
}
if (value.IsNumber())
{
return engine.Number.Construct(value.AsNumber());
}
if (value.IsString())
{
return engine.String.Construct(value.AsString());
}
throw new JavaScriptException(engine.TypeError);
}
/// <summary>
/// http://www.ecma-international.org/ecma-262/5.1/#sec-9.3
/// </summary>
/// <param name="o"></param>
/// <returns></returns>
public static double ToNumber(JsValue o)
{
// check number first as this is what is usually expected
if (o.IsNumber())
{
return o.AsNumber();
}
if (o.IsObject())
{
var p = o.AsObject() as IPrimitiveInstance;
if (p != null)
{
o = p.PrimitiveValue;
}
}
if (o == Undefined.Instance)
{
return double.NaN;
}
if (o == Null.Instance)
{
return 0;
}
if (o.IsBoolean())
{
return o.AsBoolean() ? 1 : 0;
}
if (o.IsString())
{
var s = o.AsString().Trim();
if (String.IsNullOrEmpty(s))
{
return 0;
}
if ("+Infinity".Equals(s) || "Infinity".Equals(s))
{
return double.PositiveInfinity;
}
if ("-Infinity".Equals(s))
{
return double.NegativeInfinity;
}
// todo: use a common implementation with JavascriptParser
try
{
if (!s.StartsWith("0x", StringComparison.OrdinalIgnoreCase))
{
var start = s[0];
if (start != '+' && start != '-' && start != '.' && !char.IsDigit(start))
{
return double.NaN;
}
double n = Double.Parse(s,
NumberStyles.AllowDecimalPoint | NumberStyles.AllowLeadingSign |
NumberStyles.AllowLeadingWhite | NumberStyles.AllowTrailingWhite |
NumberStyles.AllowExponent, CultureInfo.InvariantCulture);
if (s.StartsWith("-") && n.Equals(0))
{
return -0.0;
}
return n;
}
int i = int.Parse(s.Substring(2), NumberStyles.HexNumber, CultureInfo.InvariantCulture);
return i;
}
catch (OverflowException)
{
return s.StartsWith("-") ? double.NegativeInfinity : double.PositiveInfinity;
}
catch
{
return double.NaN;
}
}
return ToNumber(ToPrimitive(o, Types.Number));
}
