设置动态模式匹配器的方法

时间:2016-01-27 11:23:46

标签: lua lua-patterns

请查看此问题Pattern ^u.meta(\.|$) not working as expected,该问题具有我需要的预期行为。

更改

在模式ArrayAdapter<String> adapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, configureList(idRuta, rocodromo, dificultad)) { @Override public View getView(int position, View convertView, ViewGroup parent) { View view = super.getView(position, convertView, parent); TextView text = (TextView) view.findViewById(android.R.id.text1); if(colores.get(position).equals("0")) { text.setBackgroundColor(Color.GREEN); } else if(colores.get(position).equals("1")) { text.setBackgroundColor(Color.RED); } else if(colores.get(position).equals("2")) { text.setBackgroundColor(Color.YELLOW); } else { text.setBackgroundColor(Color.WHITE); } return view; } }; 或lua ^u.meta(\.|$)'^u%.meta%f[\0.]'中,我需要的更改'^u%.meta%f[%z.]'可以是用户从变量定义的任何内容。模式应该是通用的/动态的,以匹配变量中设置的内容。

例如:

u.meta

解决方案1 ​​

所以,如果可能的话,我在想的是lua模式中的-- should return 'u.meta', and pattern should match local pattern = 'u.meta' print(string.match("u.meta.admin", '^u%.meta%f[\0.]')) -- u.meta -- should return 'nil', and pattern should fail local pattern = 'u.meta' print(string.match("u.domain.admin", '^u%.meta%f[\0.]')) -- nil -- should return 'anything.anything', and pattern should match local pattern = 'anything.anything' print(string.match("anything.anything.something", '^anything%.anything%f[\0.]') -- anything.anything -- should return nil, and pattern should fail local pattern = 'anything.anything' print(string.match("fake.fake.something", '^anything%.anything%f[\0.]') -- nil

interpolation

工作解决方案2

我已经在方法的帮助下工作了。但我仍然需要手动调用这些模式。如果我们可以从模式本身解决这个问题,那就太棒了

示例:

"^#{pattern}%f[\0.]"

2 个答案:

答案 0 :(得分:1)

如果您需要支持用户输入作为正则表达式模式的文字部分,则需要引入一个转义函数,以便使用%转义所有魔术字符。然后,只与自定义边界(^字符串的开头连接,并且 %f[%z.]表示字符串或点的结尾。

function escape (s)
      return string.gsub(s, '[.*+?^$()[%%-]', "%%%0")
end
function pattern_matcher(v, pattern) return string.match(v, pattern) end

word = "u.meta"
print(pattern_matcher("u.meta.something", '^' .. escape(word) .. '%f[%z.]')) -- u.meta

请参阅this demo

escape函数中,替换模式中的前两个%%表示一个%%0反向引用整个匹配({{3}之一})

答案 1 :(得分:1)

这是我的最终解决方案:

-- USAGE:
--
--  local t     = {}
--  t['roles']  = 'u.meta.admin'
--  match_roles(t, 'u.meta') -- u.meta
--  match_roles(t, 'u.fake') -- nil
--
-- SOLUTION 1
--------------
--
-- function u_meta(v) return string.match(v, '^u%.meta%f[%z.]') end
-- function u_domain(v) return string.match(v, '^u%.domain%f[%z.]') end
-- 
-- function match_roles(table, pattern)
--   for _, value in pairs(table) do
--     if pattern == "u.meta" then
--       if pattern == u_meta(value) then return true end
--     elseif pattern == "u.domain" then
--       if pattern == u_domain(value) then return true end
--     end
--     return false
--   end
-- end

-- SOLUTION 2
---------------
--
-- function pattern_matcher(v, p) return string.match(v, p) end
-- function match_roles(table, role, pattern)
--   for _, value in pairs(table) do
--     if role == pattern_matcher(value, pattern) then return true end
--     return false
--   end
-- end

-- SOLUTIN - 3 (GENERIC SOLUTION) - Thanks Wiktor for pattern
---------------------------------

function escape (s) return string.gsub(s, '[.*+?^$()[%%-]', "%%%0") end
function pattern_matcher(v, pattern) return string.match(v, pattern) end
function match_roles(table, pattern)
  for _, value in pairs(table) do
    if pattern == pattern_matcher(value, '^' .. escape(pattern) .. '%f[%z.]') then return true end
    return false
  end
end


-- UNIT TEST
-- ---------
--
-- Below section covers unit test in lua.
-- we are using `luaunit` unit-testing framework that works for lua.
-- NOTE: LuaUnit works with Lua 5.1, 5.2, 5.3 and luajit (v1 and v2.1),
-- http://luaunit.readthedocs.org/en/latest/
--
package.path = './lib/?.lua;' .. package.path
luaunit = require('luaunit')
local t = {}

function test_meta_user_should_be_true()
  t["roles"] = 'u.meta.admin.system'
  luaunit.assertEquals( match_roles(t, 'u.meta'), true )
end

function test_meta_admin_should_be_true()
  t["roles"] = 'u.meta.admin'
  luaunit.assertEquals( match_roles(t, 'u.meta'), true )
end

function test_system_admin_should_be_true()
  t["roles"] = 'u.meta.admin.system'
  luaunit.assertEquals( match_roles(t, 'u.meta'), true )
end

function test_invalid_meta_admin_should_be_false()
  t["roles"] = 'u.meta_admin'
  luaunit.assertEquals( match_roles(t, 'u.meta'), false )
end

function test_invalid_meta_admin_system_should_be_false()
  t["roles"] = 'u.meta_admin_system'
  luaunit.assertEquals( match_roles(t, 'u.meta'), false )
end

function test_invalid_role_should_be_false()
  t["roles"] = 'u.meta-admin'
  luaunit.assertEquals( match_roles(t, 'u.meta'), false )
end

function test_domain_should_not_allow_in_meta()
  t['roles'] = 'u.domain'
  luaunit.assertEquals( match_roles(t, 'u.meta'), false )
end

function test_domain_user_should_be_true()
  t["roles"] = 'u.domain'
  luaunit.assertEquals( match_roles(t, 'u.domain'), true )
end

function test_domain_admin_should_be_true()
  t["roles"] = 'u.domain.admin'
  luaunit.assertEquals( match_roles(t, 'u.domain'), true )
end

function test_fake_domain_admin_should_be_falsy()
  t["roles"] = 'u.domain_admin'
  luaunit.assertEquals( match_roles(t, 'u.domain'), false )
end

function test_fake_role_should_be_falsy()
  t["roles"] = 'u.domain-admin'
  luaunit.assertEquals( match_roles(t, 'u.domain'), false )
end

function test_user_should_either_domain_or_meta ()
  t["roles"] = 'u'
  luaunit.assertEquals( match_roles(t, 'u.domain'), false )
end

function test_meta_user_in_domain_should_be_false ()
  t["roles"] = 'u.meta'
  luaunit.assertEquals( match_roles(t, 'u.domain'), false )
end

function test_meta_admin_in_domain_should_be_false ()
  t["roles"] = 'u.meta.admin'
  luaunit.assertEquals( match_roles(t, 'u.domain'), false )
end

function test_system_admin_in_domain_should_be_false ()
  t["roles"] = 'u.meta.admin.system'
  luaunit.assertEquals( match_roles(t, 'u.domain'), false )
end

function test_fake_meta_admin_in_domain_should_be_true ()
  t["roles"] = 'u.meta_admin'
  luaunit.assertEquals( match_roles(t, 'u.domain'), false )
end

function test_fake_system_admin_in_domain_should_be_true ()
  t["roles"] = 'u.meta_admin_system'
  luaunit.assertEquals( match_roles(t, 'u.domain'), false )
end

function test_fake_meta_role_in_domain_should_be_true ()
  t["roles"] = 'u.meta-admin'
  luaunit.assertEquals( match_roles(t, 'u.domain'), false )
end

function test_anything_should_match_correct_pattern()
  t['roles'] = 'a.b.c.z'
  luaunit.assertEquals( match_roles(t, 'a.b'), true )
end

function test_anything_should_fail_incorrect_pattern()
  t['roles'] = 'a.b_c'
  luaunit.assertEquals( match_roles(t, 'a.b'), false )
end

-- Exit after testcases finished
os.exit( luaunit.LuaUnit.run() )