Favour composition over inheritance for Stream

[lmmx]

(Note: after review, this may end up indicating beeb’s interface is the one to edit)

Following the guide here: https://python-patterns.guide/gang-of-four/composition-over-inheritance/

• The principle to “favour composition over inheritance” is apparently a desirable design pattern
• The “decorator pattern” (a class which wraps around a pre-existing class to add functionality) was the memoised dynamic inheritance I disliked when considering how to subclass beeb’s Stream class but also leave it open to others
  • in fact “multiple inheritance” and “dynamic class building” are both listed as “dodges”!

Solution # 1: The Adapter Pattern
Solution # 2: The Bridge Pattern
Solution # 3: The Decorator Pattern
Solution # 4: Beyond the Gang of Four patterns
Dodge: “if” statements
Dodge: Multiple Inheritance
Dodge: Mixins
Dodge: Building classes dynamically’

I prefer the ‘bridge’ pattern, and suggest switching to that: supplying a handler class from which the other methods would acquire their action from (TODO: review)

• The downside is that it isn’t wrapped up neatly, and would require the object to be created in advance. I want to just specify the broadcaster as a string, not have to import the broadcaster-specific class