lua迭代器示例

function iter(t)    local i = 0     local n = table.getn(t)    return function ()        i = i + 1        if(i <=n ) then            return t[i]        else             return nil        end    endendar = {1, 2, 3}ariter = iter(ar)while true do    local e = ariter()    if(e == nil) then        break    end    print(e)end