fun/jottary.bruijn

# a small Jottary (unary Jot) interpreter
# also serves as example usage of monadic list operations
# run with "printf 1...1 | bruijn jottary.bruijn"

:import std/Combinator .
:import std/List .
:import std/Monad .
:import std/Number .

go [eval-r (<~>((concat huh) !! 0) ; i)]
	huh (\replicate-m (l : {}r)) <$> (iterate ++‣ (+0))
		l [(0 s) k]
		r [s (k 0)]

:test (go (+0)) (i)
:test (go (+1)) ((i s) k)
:test (go (+2)) (s (k i))
:test (go (+3)) (i s k s k)
:test (go (+4)) (s (k (i s k)))
:test (go (+5)) (((s (k i)) s) k)
:test (go (+6)) (s (k (s (k i))))
:test (go (+59)) (k)
:test (go (+503)) (s)

main go ∘ length