finish-if
loop clause
(finish-if test)
When used within the main body of a loop, transfers control to the finally
clause of that loop if test is true.
make-html > (loop
(for i in '(1 2 3 a 5 6))
(finish-if (symbol? i))
(collecting i)
(finally (collecting 999)))
it: (1 2 3 999)