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cls/mk_idmap.sml

Last active April 9, 2018 21:27
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Higher-order relabelling function, ported from OCaml to Standard ML
Raw
mk_idmap.sml
exception NotFound
fun mk_idmap (mk_id : unit -> 'b) : ''a list -> ''a -> 'b =
foldl
(fn (x, acc) =>
let val new_id = mk_id () in
fn id => if id = x then new_id else acc id
end)
(fn _ => raise NotFound)
val mk_id : unit -> int =
let val id = ref 0 in
fn () => (id := !id + 1; !id)
end
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