alt Hacker News> There are surely cases where having an interface as an abstraction and multiple implementations makes sense.
I think most people aren't aware of the alternative, which is: A function that can call different implementations based on some other variable.
E.g. instead of having RealDB and MockDB type have a createUser() (method), you have a createUser() (function) that switches part of it's logic based on what DB is selected.
That's the prodecural way of achieving the same thing without needing a concept for virtual functions.
Casey explains this in the long discussion with Uncle Bob.
Replies
aidos • today at 8:22 PM
Are you suggesting something like this?
def createUesr(db):
if db is type1:
behaviour1
if db is type2:
behaviour2➕ show 1 reply
Yes, but there's not a chance that there's a material difference in performance between those options because of virtual functions.
Unless you're doing something really stupid, nothing other than the DB access is going to be worth optimizing. If those two options are accessing the DB in exactly the same way, then they will probably be within 1% of each other in performance.