ets:update_counter實現數字循環

首先初始化爲1 

ets:insert(?MODULE, {seq, 1}), 

ets:update_counter(e, seq, {2,1,8,1}).

 

1

145> ets:update_counter(e, seq, {2,1,4,1}).

2

146> ets:update_counter(e, seq, {2,1,4,1}).

3

147> ets:update_counter(e, seq, {2,1,4,1}).

4

148> ets:update_counter(e, seq, {2,1,4,1}).

1

149> ets:update_counter(e, seq, {2,1,4,1}).

2