[strken]

There are some things that should be in one long function (or method).

Consider dealing with the output of a (lexical) tokeniser. It is much easier to maintain a massive switch statement (or a bunch of ifs/elseifs) to handle each token, with calls to other functions to do the actual processing, such that each case is just a token and a function call. Grouping them in some way not required by the code is an illusory "gain": it hides the complexity of the actual function in a bunch of files you don't look at, when this is not a natural abstraction of the problem at all and when those files introduce extra layers of flow control where tricky bugs can hide. Or see the "PLEASE DO NOT ATTEMPT TO SIMPLIFY THIS CODE" comment from the Kubernetes source[0]. A 300 line function that does one thing and which cannot be usefully divided into smaller units is more maintainable than any alternative. Attempting to break it up will make it worse.

That being said, I agree that nearly all 300 line functions in the wild are not like this.

[0] https://github.com/kubernetes/kubernetes/blob/ec2e767e593953...