[sebcat]

> i can’s shake the feeling that callback passing and generator coroutines are a fad [...]

Callback passing and coroutines are well known techniques that's been around for a while. Generators are just coroutines that yield to their parent. I remember using these concepts in C and Tcl ~15 years ago[1] and they were well known then. According to wikipedia (citing Knuth), the term coroutine was coined in the late 50's by Conway.

Callback passing and coroutines suits some problems well. Sure there are situations where they do not fit and if people use a hammer for all of their problems they will create new ones. I wouldn't call it a fad, though the techniques may be a bit hyped up in some circles.

[1] I don't remember when Tcl got the coroutine package, that may have been later