public static Type CastTypes(Type a, Type b, Type preferredType = null)
{
if (a.ID == TypeID.Array || b.ID == TypeID.Array)
{
return(null);
}
//Types the same
if (a.ID == b.ID && a.GetBase() == b.GetBase())
{
return(a);
}
//Types the same, but different base
if (a.ID == b.ID && a.GetBase() != b.GetBase())
{
//Cast to bigger type
return(a.GetBase() > b.GetBase() ? a : b);
}
//if we prefer something
if (preferredType != null)
{
var type = CastTypes(a, b, null);
if (type == null)
{
return(null);
}
return(CastTypes(type, preferredType, null));
}
else
{
//We cant cast string and array to anything else
if (a.ID == TypeID.String || b.ID == TypeID.String)
{
return(null);
}
//Cast integers to float
if (a.ID == TypeID.Float && b.ID != TypeID.Float)
{
return(a);
}
if (b.ID == TypeID.Float && a.ID != TypeID.Float)
{
return(b);
}
//choose best option
var resultSigned = a.ID == TypeID.UInteger || b.ID == TypeID.UInteger;
var resultBase = Math.Max(a.GetBase(), b.GetBase());
return(GetNumericType(resultSigned, resultBase));
}
}
public static bool CanCastAssignment(Type dest, Type src)
{
if (dest.ID == TypeID.String || src.ID == TypeID.String)
{
return(false);
}
if (dest.ID == TypeID.Array && src.ID == TypeID.Array)
{
return(dest == src);
}
return(dest.GetBase() >= src.GetBase() && (dest.ID != TypeID.Integer && dest.ID != TypeID.UInteger || src.ID != TypeID.Float));
}