Class/Interface Modeling of Ranges

[BCS]

Hello dsimcha,


> 3.  Can we simplify this by using runtime exceptions instead of
> compile time errors for some of this stuff?  For example, every range
> would have a hasLength() method and a length() method.  If hasLength()
> is false, length() would throw.  Though this sacrifices compile time
> error checking, it might be better in some ways.  For example, if a
> given compile time type may or may not have length depending on its
> runtime type, you could check at runtime whether it has a length and
> adapt your handling of it accordingly.
> 

make hasLength a static const variable and it can be used for reflection 
if you need polymorphism add a function that returns this.hasLength. Following 
that pattern, you could make much of the boiler plate into a mixin:

template Range()
{
    bool p_hasLength() { return this.hasLength; }
    int length() { static if(this.hasLength) return iLength() else thrown 
... ; }
}