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; LIB
(union! Maybe
(just value)
(nothing))
(let! Maybe/map (\[f m]
(match (kind m)
"Maybe/Just" (Maybe/just (f (Maybe/Just/get-value m)))
"Maybe/Nothing" (Maybe/nothing))))
(let! Maybe/and-then (\[f m]
(match (kind m)
"Maybe/Just" (f (Maybe/Just/get-value m))
"Maybe/Nothing" (Maybe/nothing))))
; TESTING
;; (let! print-line! (\[s]
;; (print! (concat s "\n"))))
;; (let! a (Maybe/just 10))
;; (let! b (Maybe/nothing))
;; (Maybe/map (+ 5) a)
;; (Maybe/map (+ 5) b)
;; (Maybe/and-then (\[n] (Maybe/just (+ n 5))) a)
;; (Maybe/and-then (\[n] (Maybe/just (+ n 5))) b)
;; (let! m (Maybe/just 10))
;; (match m
;; (Maybe/just _)
;; (print-line! (fmt "found just {0}!" [(Maybe/Just/get-value m)]))
;; (Maybe/nothing)
;; (print-line! "found nothing!"))
;; (let! m (Maybe/just 10))
;; (pipe m [
;; (Maybe/map (+ 5))
;; (Maybe/and-then (\[val] (Maybe/just (- val 3))))
;; ])
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