[tyrrrz]

To me "avoiding mutations" does not mean "no mutations", but rather "no mutations in-between states in a state machine". The system should model state as an immutable snapshot, while mutations when forming that state are completely acceptable.

[alkonaut]

There is obviously mutation at some level of abstraction but usually one form of coding is idiomatic and one isn’t. I’m all for using immutable data and pure functions, but I’d discard a language and standard library that doesn’t have a good/idiomatic story for e.g mutating large arrays in place or has a good selection of contiguous (array-backed) collections be too limited for many types of work.