private ConstantWrapper StrictNotEqual(ConstantWrapper left, ConstantWrapper right)
{
ConstantWrapper newLiteral = null;
if (m_parser.Settings.IsModificationAllowed(TreeModifications.EvaluateNumericExpressions))
{
PrimitiveType leftType = left.PrimitiveType;
if (leftType == right.PrimitiveType)
{
// the values are the same type
switch (leftType)
{
case PrimitiveType.Null:
// null !== null is false
newLiteral = new ConstantWrapper(false, PrimitiveType.Boolean, null, m_parser);
break;
case PrimitiveType.Boolean:
// compare boolean values
newLiteral = new ConstantWrapper(left.ToBoolean() != right.ToBoolean(), PrimitiveType.Boolean, null, m_parser);
break;
case PrimitiveType.String:
// compare string ordinally
if (left.IsOkayToCombine && right.IsOkayToCombine)
{
newLiteral = new ConstantWrapper(string.CompareOrdinal(left.ToString(), right.ToString()) != 0, PrimitiveType.Boolean, null, m_parser);
}
break;
case PrimitiveType.Number:
try
{
// compare the values
// +0 and -0 are treated as "equal" in C#, so we don't need to test them separately.
// and NaN is always unequal to everything else, including itself.
if (left.IsOkayToCombine && right.IsOkayToCombine)
{
newLiteral = new ConstantWrapper(left.ToNumber() != right.ToNumber(), PrimitiveType.Boolean, null, m_parser);
}
}
catch (InvalidCastException)
{
// some kind of casting in ToNumber caused a situation where we don't want
// to perform the combination on these operands
}
break;
}
}
else
{
// if they aren't the same type, they are not equal
newLiteral = new ConstantWrapper(true, PrimitiveType.Boolean, null, m_parser);
}
}
return newLiteral;
}
private ConstantWrapper Modulo(ConstantWrapper left, ConstantWrapper right)
{
ConstantWrapper newLiteral = null;
if (left.IsOkayToCombine && right.IsOkayToCombine
&& m_parser.Settings.IsModificationAllowed(TreeModifications.EvaluateNumericExpressions))
{
try
{
double leftValue = left.ToNumber();
double rightValue = right.ToNumber();
double result = leftValue % rightValue;
if (ConstantWrapper.NumberIsOkayToCombine(result))
{
newLiteral = new ConstantWrapper(result, PrimitiveType.Number, null, m_parser);
}
else
{
if (!left.IsNumericLiteral && ConstantWrapper.NumberIsOkayToCombine(leftValue))
{
left.Parent.ReplaceChild(left, new ConstantWrapper(leftValue, PrimitiveType.Number, left.Context, m_parser));
}
if (!right.IsNumericLiteral && ConstantWrapper.NumberIsOkayToCombine(rightValue))
{
right.Parent.ReplaceChild(right, new ConstantWrapper(rightValue, PrimitiveType.Number, right.Context, m_parser));
}
}
}
catch (InvalidCastException)
{
// some kind of casting in ToNumber caused a situation where we don't want
// to perform the combination on these operands
}
}
return newLiteral;
}
private ConstantWrapper GreaterThanOrEqual(ConstantWrapper left, ConstantWrapper right)
{
ConstantWrapper newLiteral = null;
if (m_parser.Settings.IsModificationAllowed(TreeModifications.EvaluateNumericExpressions))
{
if (left.IsStringLiteral && right.IsStringLiteral)
{
if (left.IsOkayToCombine && right.IsOkayToCombine)
{
// do a straight ordinal comparison of the strings
newLiteral = new ConstantWrapper(string.CompareOrdinal(left.ToString(), right.ToString()) >= 0, PrimitiveType.Boolean, null, m_parser);
}
}
else
{
try
{
// either one or both are NOT a string -- numeric comparison
if (left.IsOkayToCombine && right.IsOkayToCombine)
{
newLiteral = new ConstantWrapper(left.ToNumber() >= right.ToNumber(), PrimitiveType.Boolean, null, m_parser);
}
}
catch (InvalidCastException)
{
// some kind of casting in ToNumber caused a situation where we don't want
// to perform the combination on these operands
}
}
}
return newLiteral;
}