module Infix:sig..end
BatMapval (-->) : 'a BatMap.S.t -> BatMap.S.key -> 'amap-->key returns the current binding of key in map,
or raises Not_found. Equivalent to find key map.val (<--) : 'a BatMap.S.t -> BatMap.S.key * 'a -> 'a BatMap.S.tmap<--(key, value) returns a map containing the same bindings as
map, plus a binding of key to value. If key was already bound
in map, its previous binding disappears. Equivalent
to add key value map