function
boot.janet on line 146, column 1
(assert x &opt err)
Throw an error if x is not truthy.
(var a 0)
(assert (pos? a) "A is definitely not positive")
# error: A is definitely not positive
# in assert [boot.janet] on line 149, column 11
# in _thunk [repl] (tailcall) on line 3, column 1