macro
boot.janet on line 311, column 1
(defer form & body)
Run form unconditionally after body, even if the body throws an
error. Will also run form if a user signal 0-4 is received.
(var a false)
(defer (set a 42)
(set a true)
(error "Oh no!"))
# error: Oh no!
(pp a) # => prints 42