lua中的正则表达式模式问题

例：

/school/student/studentname1/detail/55/address/address1

我能够传递获取所需的细节,如,

local s1,s2,s3 =myString:match("/school/student/(.-)/detail/(.-)/address/(.-)")

现在的问题是我的字符串可以

myString = /school/student/studentname1

要么

myString = /school/student/studentname1/detail/55

在那种情况下,我的正则表达式失败,任何帮助？

local all_fields = { student = 1, detail = 2, address = 3 }

local function parse(str)
   local info = {}
   local index
   for w in str:gmatch"/([^/]+)" do
      if index then
         info[index] = w
         index = nil
      else
         index = all_fields[w]
      end
   end
   return (table.unpack or unpack)(info, 1, 3)
end

local myString = '/school/student/studentname1/detail/55/address/address1'
local s1, s2, s3 = parse(myString)
print(s1, s2, s3)

myString = '/school/student/studentname1/address/address1'
s1, s2, s3 = parse(myString)
print(s1, s2, s3)

myString = '/school/student/studentname1/detail/55'
s1, s2, s3 = parse(myString)
print(s1, s2, s3)