public override async Task <object> Evaluate(EvaluationContext ctx)
{
object left = await Left.Evaluate(ctx);
object right = await Right.Evaluate(ctx);
// String concatenation
if (Operator == "+" && left is string || left is char || right is string || right is char)
{
return(ToString(left) + ToString(right));
}
// Numbers
var commonType = NumericUtil.CommonNumericType(left, right);
if (commonType == null)
{
if (!NumericUtil.IsNumericType(left))
{
throw new TemplateException($"Operator '{Operator}' could not be applied. Operand ({Left}) does not evaluate to a numeric value");
}
else if (!NumericUtil.IsNumericType(right))
{
throw new TemplateException($"Operator '{Operator}' could not be applied. Operand ({Right}) does not evaluate to a numeric value");
}
else
{
throw new Exception($"Operator '{Operator}' could not be applied"); // Developer mistake
}
}
return(Operator switch
{
"/" => NumericUtil.Divide(left, right, commonType, Right),
"%" => NumericUtil.Modulo(left, right, commonType, Right),
"*" => NumericUtil.Multiply(left, right, commonType),
"+" => NumericUtil.Add(left, right, commonType),
"-" => NumericUtil.Subtract(left, right, commonType),
_ => throw new Exception($"Unknown operator {Operator}"),// Future proofing
});
public override async Task <object> Evaluate(EvaluationContext ctx)
{
object leftObj = await Left.Evaluate(ctx);
object rightObj = await Right.Evaluate(ctx);
var numericType = NumericUtil.CommonNumericType(leftObj, rightObj);
if (numericType != null)
{
IComparable left = NumericUtil.CastToNumeric(leftObj ?? 0, numericType);
IComparable right = NumericUtil.CastToNumeric(rightObj ?? 0, numericType);
return(Operator switch
{
"=" => left.CompareTo(right) == 0,
"!=" => left.CompareTo(right) != 0,
"<>" => left.CompareTo(right) != 0,
"<=" => left.CompareTo(right) <= 0,
">=" => left.CompareTo(right) >= 0,
"<" => left.CompareTo(right) < 0,
">" => left.CompareTo(right) > 0,
_ => throw new TemplateException($"Unknown comparison operator {Operator}"),// Future proofing
});