WIP

.luacheckrc

@@ -1,3 +1,7 @@
 unused_args     = false
 max_line_length = false
 redefined       = false
+
+globals = {
+    "ngx",
+}

README.md

@@ -27,11 +27,13 @@ The router can be run in different runtimes such as Lua, LuaJIT, or OpenResty.
 
 **Custom matcher:** The router has two efficient matchers built in, MethodMatcher(`method`) and HostMatcher(`host`). They can be disabled via `opts.matcher_names`. You can also add your custom matchers via `opts.matchers`. For example, an IpMatcher to evaluate whether the `ctx.ip` is matched with the `ips` of a route.
 
+**Regular Expression:** You can define regex pattern in variables. a variable without regex pattern is treated as `[^/]+`.  
+
+- `/users/{id:\\d+}/profile-{year:\\d{4}}.{format:(html|pdf)}`
+
 **Features in the roadmap**:
 
 - Expression condition: defines custom matching conditions by using expression language.
-- Regex in variable
-
 
 ## 📖 Getting started
 

radix-router-dev-1.rockspec

@@ -22,7 +22,7 @@ description = {
 }
 
 dependencies = {
-  "lua >= 5.1, < 5.5"
+  "lrexlib-pcre2",
 }
 
 build = {

spec/parser_spec.lua

@@ -14,7 +14,8 @@ describe("parser", function()
         ["/aa/{var1}/cc/{var2}"] = { "/aa/", "{var1}", "/cc/", "{var2}" },
         ["/user/profile.{format}"] = { "/user/profile.", "{format}" },
         ["/user/{filename}.{format}"] = { "/user/", "{filename}", ".", "{format}" },
-        ["/aa/{name:[0-9]+}/{*suffix}"] = { "/aa/", "{name:[0-9]+}", "/", "{*suffix}" }
+        ["/aa/{name:[0-9]+}/{*suffix}"] = { "/aa/", "{name:[0-9]+}", "/", "{*suffix}" },
+        ["/user/{id:\\d+}/profile-{year:\\d{4}}.{format:(html|pdf)}"] = { "/user/", "{id:\\d+}", "/profile-", "{year:\\d{4}}", ".", "{format:(html|pdf)}"  },
       }
 
       for path, expected_tokens in pairs(tests) do
@@ -63,5 +64,38 @@ describe("parser", function()
         assert.same(test.params, params, "assertion failed: " .. i)
       end
     end)
+    it("compile_regex()", function()
+      local tests = {
+        {
+          path = "/a/b/c",
+          regex = "^\\Q/a/b/c\\E$"
+        },
+        {
+          path = "/a/{b}/c/{d}",
+          regex = "^\\Q/a/\\E[^/]+\\Q/c/\\E[^/]+$"
+        },
+        {
+          path = "/a/{b:\\d+}/c/{d:\\d{3}}",
+          regex = "^\\Q/a/\\E\\d+\\Q/c/\\E\\d{3}$"
+        },
+        {
+          path = "/a/{*catchall}",
+          regex = "^\\Q/a/\\E.*$"
+        },
+        {
+          path = "/a/{b}/c/{*catchall}",
+          regex = "^\\Q/a/\\E[^/]+\\Q/c/\\E.*$"
+        },
+        {
+          path = "/a/{b:[a-z]+}/c/{*catchall}",
+          regex = "^\\Q/a/\\E[a-z]+\\Q/c/\\E.*$"
+        },
+      }
+      for i, test in pairs(tests) do
+        local parser = Parser.new("default")
+        local regex = parser:update(test.path):compile_regex()
+        assert.same(test.regex, regex, "assertion failed: " .. i)
+      end
+    end)
   end)
 end)

spec/router_spec.lua

@@ -88,7 +88,7 @@ describe("Router", function()
 
       local router, err = Router.new({}, { matcher_names = { "inexistent" } })
       assert.is_nil(router)
-      assert.equal("invalid matcher name: inexistent", err)
+      assert.equal("invalid args opts: invalid matcher name: inexistent", err)
     end)
   end)
   describe("match", function()
@@ -480,6 +480,50 @@ describe("Router", function()
       assert.same({ cat = "suffix" }, binding)
     end)
   end)
+  describe("regex", function()
+    it("sanity", function()
+      local router = Router.new({
+        {
+          paths = { "/a/{b:\\d{3}}/c" },
+          handler = "/a/{b:\\d{3}}/c",
+        },
+        {
+          paths = { "/a/{b:\\d+}/c" },
+          handler = "/a/{b:\\d+}/c",
+        },
+        {
+          paths = { "/a/{b:[a-z]+}/c" },
+          handler = "/a/{b:[a-z]+}/c",
+        },
+        {
+          paths = { "/a/{b:[^/]+}/c" },
+          handler = "/a/{b:[^/]+}/c",
+        },
+        {
+          paths = { "/users/{id:\\d+}/profile-{year:\\d{4}}.{format:(html|pdf)}" },
+          handler = "1",
+        },
+        {
+          paths = { "/escape/{var}/{var1:[a-z]+}|{var2:[A-Z]+}|{var3:\\d+}|{var4:(html|pdf)}" },
+          handler = "2",
+        }
+      })
+      assert.equal("/a/{b:\\d+}/c", router:match("/a/2024/c"))
+      assert.equal("/a/{b:\\d{3}}/c", router:match("/a/123/c"))
+      assert.equal("/a/{b:[a-z]+}/c", router:match("/a/abc/c"))
+      assert.equal("/a/{b:[^/]+}/c", router:match("/a/abc0/c"))
+
+      -- /users/{id:\\d+}/profile-{year:\\d{4}}.{format:html|pdf}
+      assert.equal("1", router:match("/users/123/profile-2024.html"))
+      assert.equal("1", router:match("/users/123/profile-2024.pdf"))
+      assert.equal(nil, router:match("/users/abc/profile-2024.html"))
+      assert.equal(nil, router:match("/users/123/profile-123.html"))
+      assert.equal(nil, router:match("/users/123/profile-2024.jpg"))
+
+      -- /escape/{var}/{var1:[a-z]+}|{var2:[A-Z]+}|{var3:\\d+}|{var4:(html|pdf)}
+      assert.equal("2", router:match("/escape/var/aaa|AAA|111|html"))
+    end)
+  end)
   describe("matching order", function()
     it("first registered first match", function()
       local router = Router.new({

spec/utils_spec.lua

@@ -36,4 +36,18 @@ describe("utils", function()
     assert.equal(0, utils.lcp("", "/abcd"))
     assert.equal(0, utils.lcp("a", "c"))
   end)
+  pending("is_digit()", function()
+    assert.is_true(utils.is_digit(string.byte("0")))
+    assert.is_true(utils.is_digit(string.byte("1")))
+    assert.is_true(utils.is_digit(string.byte("2")))
+    assert.is_true(utils.is_digit(string.byte("3")))
+    assert.is_true(utils.is_digit(string.byte("4")))
+    assert.is_true(utils.is_digit(string.byte("5")))
+    assert.is_true(utils.is_digit(string.byte("6")))
+    assert.is_true(utils.is_digit(string.byte("7")))
+    assert.is_true(utils.is_digit(string.byte("8")))
+    assert.is_true(utils.is_digit(string.byte("9")))
+    assert.is_false(utils.is_digit(string.byte("/")))
+    assert.is_false(utils.is_digit(string.byte(":")))
+  end)
 end)

src/parser/parser.lua

@@ -12,7 +12,7 @@ local parsers = {
 function Parser.new(style)
   local parser = parsers[style]
   if not parser then
-    return nil, "invalid style: " .. style
+    return nil, "unknown parser style: " .. style
   end
 
   return parser.new()

src/parser/style/default.lua

@@ -47,6 +47,7 @@ function _M:reset()
   self.anchor = 1
   self.pos = 1
   self.state = nil
+  self.bracket_depth = 0
 end
 
 
@@ -58,7 +59,8 @@ function _M:next()
   local char, token, token_type
   while self.pos <= self.path_n do
     char = byte(self.path, self.pos)
-    --print("pos: " .. self.pos .. "(" .. string.char(char) .. ")")
+    --local char_str = string.char(char)
+    --print("pos: " .. self.pos .. "(" .. char_str .. ")")
     if self.state == nil or self.state == STATES.static then
       if char == BYTE_LEFT_BRACKET then
         if self.state == STATES.static then
@@ -67,12 +69,18 @@ function _M:next()
           self.anchor = self.pos
         end
         self.state = STATES.variable_start
+        self.bracket_depth = 1
       else
         self.state = STATES.static
       end
     elseif self.state == STATES.variable_start then
-      if char == BYTE_RIGHT_BRACKET then
-        self.state = STATES.variable_end
+      if char == BYTE_LEFT_BRACKET then
+        self.bracket_depth = self.bracket_depth + 1
+      elseif char == BYTE_RIGHT_BRACKET then
+        self.bracket_depth = self.bracket_depth - 1
+        if self.bracket_depth == 0 then
+          self.state = STATES.variable_end
+        end
       end
     elseif self.state == STATES.variable_end then
       self.state = STATES.static
@@ -93,6 +101,7 @@ function _M:next()
   return token, self.token_type(token)
 end
 
+
 function _M:parse()
   self:reset()
 
@@ -108,6 +117,7 @@ function _M:parse()
   return tokens
 end
 
+
 function _M.token_type(token)
   if byte(token) == BYTE_LEFT_BRACKET and
     byte(token, #token) == BYTE_RIGHT_BRACKET then
@@ -120,15 +130,39 @@ function _M.token_type(token)
   return TOKEN_TYPES.literal
 end
 
-function _M.is_dynamic(path)
-  local patn_n = #path
-  for i = 1, patn_n do
-    local char = byte(path, i)
-    if char == BYTE_LEFT_BRACKET or char == BYTE_RIGHT_BRACKET then
-      return true
+
+local function parse_token_regex(token)
+  for i = 1, #token do
+    if byte(token, i) == BYTE_COLON then
+      return sub(token, i + 1, -2)
     end
   end
-  return false
+  return nil
+end
+
+
+-- compile path to regex pattern
+function _M:compile_regex()
+  local tokens = { "^" }
+
+  local token, token_type = self:next()
+  while token do
+    if token_type == TOKEN_TYPES.variable then
+      local pattern = parse_token_regex(token) or "[^/]+"
+      table.insert(tokens, pattern)
+    elseif token_type == TOKEN_TYPES.catchall then
+      table.insert(tokens, ".*")
+    else
+      -- quote the literal token
+      table.insert(tokens, "\\Q")
+      table.insert(tokens, token)
+      table.insert(tokens, "\\E")
+    end
+    token, token_type = self:next()
+  end
+  table.insert(tokens, "$")
+
+  return table.concat(tokens)
 end
 
 function _M:params()
@@ -240,4 +274,40 @@ function _M:bind_params(req_path, req_path_n, params, trailing_slash_mode)
   end
 end
 
+
+local function contains_regex(path)
+  local bracket_depth = 0
+
+  for i = 1, #path do
+    local char = byte(path, i)
+    if char == BYTE_LEFT_BRACKET then
+      bracket_depth = bracket_depth + 1
+    elseif char == BYTE_RIGHT_BRACKET then
+      bracket_depth = bracket_depth - 1
+    elseif char == BYTE_COLON and bracket_depth == 1 then
+      -- regex syntax {var:[^/]+}
+      -- return true only if the colon is in the first depth
+      return true
+    end
+  end
+
+  return false
+end
+
+
+local function is_dynamic(path)
+  local patn_n = #path
+  for i = 1, patn_n do
+    local char = byte(path, i)
+    if char == BYTE_LEFT_BRACKET or char == BYTE_RIGHT_BRACKET then
+      return true
+    end
+  end
+  return false
+end
+
+
+_M.contains_regex = contains_regex
+_M.is_dynamic = is_dynamic
+
 return _M

src/route.lua

@@ -10,7 +10,7 @@ local Route = {}
 local mt = { __index = Route }
 
 
-function Route.new(route, _)
+function Route.new(route)
   if route.handler == nil then
     return nil, "handler must not be nil"
   end