[SJC_Hacker]

>In order to make a new object which implements the `Map` interface, you just have to inherit from the `AbstractMap` base class and implement 1 method, `entrySet`

Used to think that way, but I now prefer the alternative - passing function(s)/lambda(s) for the necessary functionality of the dependent class.

This way is actually more flexible, as you can change behavior without modifying the override or having a bunch of switches/if-else in your required function.

So instead of 'entrySet' being defined inside MyClass, you would define it outside it, or possible as a static method, and pass it to AbstractMap when you create it.

So you don't need to have every class implement a bunch of interfaces like or Hashable, Orderable, etc. in order get the desired behavior.

Now I guess you would come back about you shouldn't be able to able to do that outside the class, but I also think those are also bad ideas. Python famous gets away with not having private/protected (although there is a way you can kinda of get something similar).

[microflash]

It is just a matter of how flexibility you want to expose through your API. Sometimes a rigid and stricter API is the right choice where you want the API itself as the guardrail against non-standard patterns.

[nailer]

Scopes and closures Give you guard rails and don’t require gluing functions to state unnecessary.