Bad error message with structs that have partially implement interfaces.

The compiler needs to inform the user that they NEED to implement all of the contracts defined in an interface when they implement that interface within a struct.

The problem is the compiler tries to turn a struct abstract, which is invalid; this is because classes are normally marked abstract if they do not implement all of an interfaces contracts.

The following code should exhibits this bad behavior.

import System
struct test(IComparable):
pass