Interpret a list of (key, value) pairs as a map in which only the first occurrence of a key affects the semantics, i.e.:
List.Assoc.xxx alist ...args...
is always the same as (or at least sort of isomorphic to):
Map.xxx (alist |> Map.of_alist_multi |> Map.map ~f:List.hd) ...args...
include sig ... end
val t_of_sexp : (Base.Sexp.t ‑> 'a) ‑> (Base.Sexp.t ‑> 'b) ‑> Base.Sexp.t ‑> ('a, 'b) t
val sexp_of_t : ('a ‑> Base.Sexp.t) ‑> ('b ‑> Base.Sexp.t) ‑> ('a, 'b) t ‑> Base.Sexp.t
val find : ('a, 'b) t ‑> equal:('a ‑> 'a ‑> bool) ‑> 'a ‑> 'b option
val find_exn : ('a, 'b) t ‑> equal:('a ‑> 'a ‑> bool) ‑> 'a ‑> 'b
val mem : ('a, 'b) t ‑> equal:('a ‑> 'a ‑> bool) ‑> 'a ‑> bool