let main () =
    Lazy.force a;
    Lazy.force b;
    Lazy.force c;
    Lazy.force d

WHERE

lazy c = Int 123
lazy b = String "4567"

HEADER

lazy a = Int 123
lazy d = match Lazy.force b with Int n -> n | String s -> s2i s
    where {s2i = int_of_string}

WHERE

lazy c = Int 123
lazy b = String "4567"

WHERE

type value = Int of int | String of string