Interesting! This came up because I'm porting some...

# arrow

[xenomachina]

Interesting!
This came up because I'm porting some code of mine that uses a "home-grown" Either to use arrow-kt instead, and in one place I had something like:

when (x) {
    is Either.Left -> yield(foo(x))

but with arrow I had to change it to write:

when (x) {
    is Either.Left -> yield(foo(Either.left(x)))

It took me a while to figure out why only this one bit of code was failing.