public override ValueEval Evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg0, ValueEval arg1)
{
ValueEval vA;
ValueEval vB;
try
{
vA = OperandResolver.GetSingleValue(arg0, srcRowIndex, srcColumnIndex);
vB = OperandResolver.GetSingleValue(arg1, srcRowIndex, srcColumnIndex);
}
catch (EvaluationException e)
{
return(e.GetErrorEval());
}
int cmpResult = DoCompare(vA, vB);
bool result = ConvertComparisonResult(cmpResult);
return(BoolEval.ValueOf(result));
}
private static int CompareBlank(ValueEval v)
{
if (v == BlankEval.instance)
{
return(0);
}
if (v is BoolEval)
{
BoolEval boolEval = (BoolEval)v;
return(boolEval.BooleanValue ? -1 : 0);
}
if (v is NumberEval)
{
NumberEval ne = (NumberEval)v;
//return ne.NumberValue.CompareTo(0.0);
return(NumberComparer.Compare(0.0, ne.NumberValue));
}
if (v is StringEval)
{
StringEval se = (StringEval)v;
return(se.StringValue.Length < 1 ? 0 : -1);
}
throw new ArgumentException("bad value class (" + v.GetType().Name + ")");
}
private static int DoCompare(ValueEval va, ValueEval vb)
{
// special cases when one operand is blank
if (va == BlankEval.instance)
{
return(CompareBlank(vb));
}
if (vb == BlankEval.instance)
{
return(-CompareBlank(va));
}
if (va is BoolEval)
{
if (vb is BoolEval)
{
BoolEval bA = (BoolEval)va;
BoolEval bB = (BoolEval)vb;
if (bA.BooleanValue == bB.BooleanValue)
{
return(0);
}
return(bA.BooleanValue ? 1 : -1);
}
return(1);
}
if (vb is BoolEval)
{
return(-1);
}
if (va is StringEval)
{
if (vb is StringEval)
{
StringEval sA = (StringEval)va;
StringEval sB = (StringEval)vb;
return(string.Compare(sA.StringValue, sB.StringValue, StringComparison.OrdinalIgnoreCase));
}
return(1);
}
if (vb is StringEval)
{
return(-1);
}
if (va is NumberEval)
{
if (vb is NumberEval)
{
NumberEval nA = (NumberEval)va;
NumberEval nB = (NumberEval)vb;
if (nA.NumberValue == nB.NumberValue)
{
// Excel considers -0.0 == 0.0 which is different to Double.compare()
return(0);
}
return(NumberComparer.Compare(nA.NumberValue, nB.NumberValue));
}
}
throw new ArgumentException("Bad operand types (" + va.GetType().Name + "), ("
+ vb.GetType().Name + ")");
}