使用ets：foldl作为每个记录的穷人forEach

ets:foldl

private

ets

foreach

lists

1> ets:new(ex, [named_table]).
ex
2> ets:insert(ex, {alice, "high"}).
true
3> ets:insert(ex, {bob, "medium"}).
true
4> ets:insert(ex, {charlie, "low"}).
true
5> ets:foldl(fun({Name, Adjective}, DontCare) ->
      io:format("~p has a ~p opinion of you~n", [Name, Adjective]),
      ets:delete(ex, Name),
      DontCare
   end, notused, ex).
bob has a "medium" opinion of you
alice has a "high" opinion of you
charlie has a "low" opinion of you
notused
6> ets:info(ex).
[...
 {size,0},
 ...]
7> ets:lookup(ex, bob).
[]

foldl

set