(: ABType Type)

(: AType Type)

(: A ABType)

(: A AType)

(: B ABType)

!("Bind A-first with A")

!(bind! &a-first (new-state A))

!("(get-type A-first)=" (get-type (get-state &a-first)))

!("Change A-first into B")

!(change-state! &a-first B)

!("(get-type A-first)=" (get-type (get-state &a-first)))

!("Bind B-first with B")

!(bind! &b-first (new-state B))

!("(get-type B-first)=" (get-type (get-state &b-first)))

!("Change B-first into A")

!(change-state! &b-first A)

!("(get-type B-first)=" (get-type (get-state &b-first)))

!("Bind False-first with False")

!(bind! &false-first (new-state False))

!("(get-type False-first)=" (get-type (get-state &false-first)))

!("Change False-first into Sometimes")

!(change-state! &false-first Sometimes)

!("(get-type False-first)=" (get-type (get-state &false-first)))

; Also works for custom types

(: Either Type)

!(assertEqual

(get-type Either)

Type)

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; Arrow types of functions and constructors

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(: Left (-> %Undefined% Either))

(: Right (-> %Undefined% Either))

!(assertEqual

(get-type (Left 5))

Either)

(: isLeft (-> Either Bool))

(= (isLeft (Left $x)) True)

(= (isLeft (Right $x)) False)

!(assertEqual (get-type (isLeft (Right 5))) Bool)

!(assertEqual

(get-type (isLeft (Right 5)))

(get-type (get-state (new-state (isLeft (Right 5))))))

!(bind! &is_left (isLeft (Right 5)))

!(bind! &right_7 (Right 7))

!("(get-type (isLeft (Right 5)))=" (get-type (isLeft (Right 5))))

!("(get-type (get-state (new-state (isLeft (Right 5)))))=" (get-type (get-state (new-state (isLeft (Right 5))))))

!("(get-type (get-state (new-state (Left 6))))=" (get-type (get-state (new-state (Left 6)))) )

!("(get-type (get-state (new-state (Right 7))))=" (get-type (get-state (new-state (Right 7)))) )

!("(get-type &is_left)=" &is_left (get-type &is_left))

!("(get-type &right_7)=" &right_7 (get-type &right_7))

!("bind &right_7-first with &right_7")

!(bind! &right_7-first (new-state &right_7))

!("change &right_7-first into &is_left" (change-state! &right_7-first &is_left))

!("(get-type (get-state &right_7-first))=(" (get-state &right_7-first) ")=" (get-type (get-state &right_7-first)))

!("(get-type &right_7-first)=" (get-type (get-state &right_7-first)))