/// <summary>
/// Returns the index of the given search element in the array, searching backwards from
/// <paramref name="fromIndex"/>.
/// </summary>
/// <param name="searchElement"> The value to search for. </param>
/// <param name="fromIndex"> The array index to start searching. </param>
/// <returns> The index of the given search element in the array, or <c>-1</c> if the
/// element wasn't found. </returns>
public int LastIndexOf(object searchElement, int fromIndex)
{
// If fromIndex is less than zero, it is an offset from the end of the array.
if (fromIndex < 0)
{
fromIndex += Length;
}
for (int i = Math.Min(Length - 1, fromIndex); i >= 0; i--)
{
// Get the value of the array element.
object elementValue = this[i];
// Compare the given search element with the array element.
if (elementValue != null && TypeComparer.StrictEquals(searchElement, elementValue) == true)
{
return(i);
}
}
// The search element wasn't found.
return(-1);
}
/// <summary>
/// Evaluates the expression, if possible.
/// </summary>
/// <returns> The result of evaluating the expression, or <c>null</c> if the expression can
/// not be evaluated. </returns>
public override object Evaluate()
{
// Evaluate the operands.
var left = this.Left.Evaluate();
if (left == null)
{
return(null);
}
var right = this.Right.Evaluate();
if (right == null)
{
return(null);
}
// Apply the binary operator logic.
switch (this.OperatorType)
{
case OperatorType.Add:
{
var leftPrimitive = TypeConverter.ToPrimitive(left, PrimitiveTypeHint.None);
var rightPrimitive = TypeConverter.ToPrimitive(right, PrimitiveTypeHint.None);
if (TypeUtilities.IsString(leftPrimitive) == true || TypeUtilities.IsString(rightPrimitive) == true)
{
return(TypeConverter.ToString(leftPrimitive) + TypeConverter.ToString(rightPrimitive));
}
return(TypeConverter.ToNumber(leftPrimitive) + TypeConverter.ToNumber(rightPrimitive));
}
// Arithmetic operations.
case OperatorType.Subtract:
return(TypeConverter.ToNumber(left) - TypeConverter.ToNumber(right));
case OperatorType.Multiply:
return(TypeConverter.ToNumber(left) * TypeConverter.ToNumber(right));
case OperatorType.Divide:
return(TypeConverter.ToNumber(left) / TypeConverter.ToNumber(right));
case OperatorType.Modulo:
return(TypeConverter.ToNumber(left) % TypeConverter.ToNumber(right));
case OperatorType.Exponentiation:
return(Library.MathObject.Pow(TypeConverter.ToNumber(left), TypeConverter.ToNumber(right)));
// Bitwise operations.
case OperatorType.BitwiseAnd:
return(TypeConverter.ToInt32(left) & TypeConverter.ToInt32(right));
case OperatorType.BitwiseOr:
return(TypeConverter.ToInt32(left) | TypeConverter.ToInt32(right));
case OperatorType.BitwiseXor:
return(TypeConverter.ToInt32(left) ^ TypeConverter.ToInt32(right));
case OperatorType.LeftShift:
return(TypeConverter.ToInt32(left) << (int)(TypeConverter.ToUint32(right) & 0x1F));
case OperatorType.SignedRightShift:
return(TypeConverter.ToInt32(left) >> (int)(TypeConverter.ToUint32(right) & 0x1F));
case OperatorType.UnsignedRightShift:
return((uint)TypeConverter.ToInt32(left) >> (int)(TypeConverter.ToUint32(right) & 0x1F));
// Relational operations.
case OperatorType.LessThan:
case OperatorType.LessThanOrEqual:
case OperatorType.GreaterThan:
case OperatorType.GreaterThanOrEqual:
return(PrimitiveType.Bool);
// Equality operations.
case OperatorType.Equal:
return(TypeComparer.Equals(left, right) == true);
case OperatorType.StrictlyEqual:
return(TypeComparer.StrictEquals(left, right) == true);
case OperatorType.NotEqual:
return(TypeComparer.Equals(left, right) == false);
case OperatorType.StrictlyNotEqual:
return(TypeComparer.StrictEquals(left, right) == false);
// Logical operations.
case OperatorType.LogicalAnd:
if (TypeConverter.ToBoolean(left) == false)
{
return(left);
}
return(right);
case OperatorType.LogicalOr:
if (TypeConverter.ToBoolean(left) == true)
{
return(left);
}
return(right);
// Misc
case OperatorType.InstanceOf:
case OperatorType.In:
return(null);
default:
throw new NotImplementedException(string.Format("Unsupported operator {0}", this.OperatorType));
}
}
public void StrictEquals()
{
var engine = new ScriptEngine();
// Undefined.
Assert.AreEqual(true, TypeComparer.StrictEquals(Undefined.Value, Undefined.Value));
Assert.AreEqual(false, TypeComparer.StrictEquals(Undefined.Value, Null.Value));
Assert.AreEqual(false, TypeComparer.StrictEquals(Undefined.Value, false));
Assert.AreEqual(false, TypeComparer.StrictEquals(Undefined.Value, true));
Assert.AreEqual(false, TypeComparer.StrictEquals(Undefined.Value, 0));
Assert.AreEqual(false, TypeComparer.StrictEquals(Undefined.Value, 0.0));
Assert.AreEqual(false, TypeComparer.StrictEquals(Undefined.Value, 5.5));
Assert.AreEqual(false, TypeComparer.StrictEquals(Undefined.Value, double.NaN));
Assert.AreEqual(false, TypeComparer.StrictEquals(Undefined.Value, ""));
Assert.AreEqual(false, TypeComparer.StrictEquals(Undefined.Value, " "));
Assert.AreEqual(false, TypeComparer.StrictEquals(Undefined.Value, "5.5"));
Assert.AreEqual(false, TypeComparer.StrictEquals(Undefined.Value, "foo"));
Assert.AreEqual(false, TypeComparer.StrictEquals(Undefined.Value, engine.Object.Construct()));
// Null.
Assert.AreEqual(false, TypeComparer.StrictEquals(Null.Value, Undefined.Value));
Assert.AreEqual(true, TypeComparer.StrictEquals(Null.Value, Null.Value));
Assert.AreEqual(false, TypeComparer.StrictEquals(Null.Value, false));
Assert.AreEqual(false, TypeComparer.StrictEquals(Null.Value, true));
Assert.AreEqual(false, TypeComparer.StrictEquals(Null.Value, 0));
Assert.AreEqual(false, TypeComparer.StrictEquals(Null.Value, 0.0));
Assert.AreEqual(false, TypeComparer.StrictEquals(Null.Value, 5.5));
Assert.AreEqual(false, TypeComparer.StrictEquals(Null.Value, double.NaN));
Assert.AreEqual(false, TypeComparer.StrictEquals(Null.Value, ""));
Assert.AreEqual(false, TypeComparer.StrictEquals(Null.Value, " "));
Assert.AreEqual(false, TypeComparer.StrictEquals(Null.Value, "5.5"));
Assert.AreEqual(false, TypeComparer.StrictEquals(Null.Value, "foo"));
Assert.AreEqual(false, TypeComparer.StrictEquals(Null.Value, engine.Object.Construct()));
// Boolean.
Assert.AreEqual(false, TypeComparer.StrictEquals(false, Undefined.Value));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, Null.Value));
Assert.AreEqual(true, TypeComparer.StrictEquals(false, false));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, true));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, 0));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, 0.0));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, 5.5));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, double.NaN));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, ""));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, " "));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, "5.5"));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, "foo"));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, engine.Object.Construct()));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, engine.Boolean.Construct(false)));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, engine.Boolean.Construct(true)));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, engine.Number.Construct(0)));
Assert.AreEqual(false, TypeComparer.StrictEquals(false, engine.Number.Construct(1)));
// Number.
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, Undefined.Value));
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, Null.Value));
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, false));
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, true));
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, 0));
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, 0.0));
Assert.AreEqual(true, TypeComparer.StrictEquals(5.5, 5.5));
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, double.NaN));
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, ""));
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, " "));
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, "5.5"));
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, "foo"));
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, engine.Object.Construct()));
Assert.AreEqual(false, TypeComparer.StrictEquals(5.5, engine.Number.Construct(5.5)));
Assert.AreEqual(true, TypeComparer.StrictEquals(0, 0.0));
Assert.AreEqual(true, TypeComparer.StrictEquals(5, 5.0));
Assert.AreEqual(false, TypeComparer.StrictEquals(double.NaN, double.NaN));
// String.
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", Undefined.Value));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", Null.Value));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", false));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", true));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", 0));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", 0.0));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", 5.5));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", double.NaN));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", ""));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", " "));
Assert.AreEqual(true, TypeComparer.StrictEquals("5.5", "5.5"));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", "foo"));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", engine.Object.Construct()));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", engine.Number.Construct(5.5)));
Assert.AreEqual(false, TypeComparer.StrictEquals("5.5", engine.String.Construct("5.5")));
// Object.
var temp = engine.Object.Construct();
Assert.AreEqual(true, TypeComparer.StrictEquals(temp, temp));
Assert.AreEqual(false, TypeComparer.StrictEquals(engine.Object.Construct(), engine.Object.Construct()));
Assert.AreEqual(false, TypeComparer.StrictEquals(engine.Number.Construct(5.5), engine.Number.Construct(5.5)));
Assert.AreEqual(false, TypeComparer.StrictEquals(engine.String.Construct("5.5"), engine.String.Construct("5.5")));
}