According to the doc linked by @lucaong it should still work in these examples since:
when x in 1..3
translates to:
when is_integer(x) and x >= 1 and x <= 3
Note that only integers can be considered inside a range byin.
Also, I just tried and indeed I got:
IO.puts f(5) #=> 456
IO.puts f(5.0) #=> nope
IO.puts f(5.5) #=> nope
Edit: I think that this bit is_integer(x) and might be an addition brought by an update later on..
Also it’s still interesting to know and behaves carefully with edge cases.
