Custom parameter/segment regex

Allow users to use a custom regex to match a parameter.

README.md

@@ -263,6 +263,21 @@ local rx = radix.new({
 })
 ```
 
+### Parameters in Path with a custom regex
+
+You can specify parameters on a path and use a regex to match the parameter segment of the path (see `hsegment` of [RFC1738](https://www.rfc-editor.org/rfc/rfc1738.txt).
+It is not possible to match multiple path segements in this way.
+
+```lua
+local rx = radix.new({
+    {
+        -- matches with `/user/john` but not `/user/` or `/user`
+        paths = {"/user/:uuid:[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}"}, -- for `/user/5b3c7845-b45c-4dc8-8843-0349465e0e62`, `opts.matched.user` will be `5b3c7845-b45c-4dc8-8843-0349465e0e62`
+        metadata = "metadata /user",
+    }
+})
+```
+
 [Back to TOC](#table-of-contents)
 
 # Installation

lib/resty/radixtree.lua

@@ -637,7 +637,7 @@ end
 local function fetch_pat(path)
     local pat = lru_pat:get(path)
     if pat then
-        return pat[1], pat[2]   -- pat, names
+        return pat -- pat
     end
 
     clear_tab(tmp)
@@ -646,28 +646,39 @@ local function fetch_pat(path)
         return false
     end
 
-    local names = {}
+    local name, pos, regex
     for i, item in ipairs(res) do
         local first_byte = item:byte(1, 1)
         if first_byte == string.byte(":") then
-            table.insert(names, res[i]:sub(2))
-            -- See https://www.rfc-editor.org/rfc/rfc1738.txt BNF for specific URL schemes
-            res[i] = [=[([\w\-_;:@&=!',\%\$\.\+\*\(\)]+)]=]
+            pos = str_find(res[i], ":", 3, true)
+            if pos and pos+1 < res[i]:len() then
+                name = res[i]:sub(2, pos - 1)
+                regex = res[i]:sub(pos+1)
+            else
+                name = res[i]:sub(2)
+                -- See https://www.rfc-editor.org/rfc/rfc1738.txt BNF for specific URL schemes
+                regex = [=[[\w\-_;:@&=!',\%\$\.\+\*\(\)]+]=]
+            end
 
+            res[i] = '(?<' .. name .. '>' .. regex .. ')'
         elseif first_byte == string.byte("*") then
-            local name = res[i]:sub(2)
+            name = res[i]:sub(2)
             if name == "" then
-                name = ":ext"
+                name = "__ext"
             end
-            table.insert(names, name)
+
             -- '.' matches any character except newline
-            res[i] = [=[((.|\n)*)]=]
+            res[i] = '(?<' .. name .. '>' .. [=[(?:.|\n)*)]=]
         end
     end
 
+    if name == nil then
+        return false
+    end
+
     pat = table.concat(res, [[\/]])
-    lru_pat:set(path, {pat, names}, 60 * 60)
-    return pat, names
+    lru_pat:set(path, pat, 60 * 60)
+    return pat
 end
 
 
@@ -676,9 +687,9 @@ local function compare_param(req_path, route, opts)
         return true
     end
 
-    local pat, names = fetch_pat(route.path_org)
+    local pat = fetch_pat(route.path_org)
     log_debug("pcre pat: ", pat)
-    if #names == 0 then
+    if pat == false then
         return true
     end
 
@@ -695,10 +706,14 @@ local function compare_param(req_path, route, opts)
         return true
     end
 
-    for i, v in ipairs(m) do
-        local name = names[i]
-        if name and v then
-            opts.matched[name] = v
+    for k, v in pairs(m) do
+        if type(k) == "string" and v then
+            -- Capture groups can't start with a colon.
+            if k == "__ext" then
+                opts.matched[":ext"] = v
+            else
+                opts.matched[k] = v
+            end
         end
     end
     return true

t/parameter.t

@@ -392,3 +392,39 @@ GET /t
 --- response_body
 match meta: /user/:user
 match meta: /user/:user/age/:age
+
+
+
+=== TEST 14: /user/:uuid:[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}
+--- config
+    location /t {
+        content_by_lua_block {
+            local json = require("toolkit.json")
+            local radix = require("resty.radixtree")
+            local rx = radix.new({
+                {
+                    paths = { "/user/:uuid:([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12})" },
+                    metadata = "metadata /name",
+                },
+            })
+
+            local opts = {matched = {}}
+            local meta = rx:match("/user/5b3c7845-b45c-4dc8-8843-0349465e0e62", opts)
+            ngx.say("match meta: ", meta)
+            ngx.say("matched: ", json.encode(opts.matched))
+
+            opts.matched = {}
+            meta = rx:match("/user/1", opts)
+            ngx.say("match meta: ", meta)
+            ngx.say("matched: ", json.encode(opts.matched))
+        }
+    }
+--- request
+GET /t
+--- no_error_log
+[error]
+--- response_body
+match meta: metadata /name
+matched: {"_path":"/user/:uuid:([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12})","uuid":"5b3c7845-b45c-4dc8-8843-0349465e0e62"}
+match meta: nil
+matched: []