lib/path: add method Keys and NKey, and export IsKeyExists

The Keys method return list of key in path.
The NKey method return the number of key in path.
The IsKeyExists return true if the key exist in Route; otherwise it
will return false.

lib/path/route.go

@@ -58,7 +58,7 @@ func NewRoute(rpath string) (rute *Route, err error) {
 				return nil, ErrPathKeyEmpty
 			}
 
-			if rute.isKeyExist(node.name) {
+			if rute.IsKeyExists(node.name) {
 				return nil, ErrPathKeyDuplicate
 			}
 
@@ -79,9 +79,12 @@ func NewRoute(rpath string) (rute *Route, err error) {
 	return rute, nil
 }
 
-// isKeyExist will return true if the key already exist in nodes; otherwise
-// it will return false.
-func (rute *Route) isKeyExist(key string) bool {
+// IsKeyExists will return true if the key exist in Route; otherwise it will
+// return false.
+// Remember that the key is stored in lower case, so it will be matched
+// after the parameter key is converted to lower case.
+func (rute *Route) IsKeyExists(key string) bool {
+	key = strings.ToLower(key)
 	var node *routeNode
 	for _, node = range rute.nodes {
 		if !node.isKey {
@@ -94,6 +97,22 @@ func (rute *Route) isKeyExist(key string) bool {
 	return false
 }
 
+// Keys return list of key in path.
+func (rute *Route) Keys() (keys []string) {
+	var node *routeNode
+	for _, node = range rute.nodes {
+		if node.isKey {
+			keys = append(keys, node.name)
+		}
+	}
+	return keys
+}
+
+// NKey return the number of key in path.
+func (rute *Route) NKey() (n int) {
+	return rute.nkey
+}
+
 // Parse the path and return the key-value association and true if path is
 // matched with current [Route]; otherwise it will return nil and false.
 func (rute *Route) Parse(rpath string) (vals map[string]string, ok bool) {

lib/path/route_example_test.go

@@ -11,6 +11,58 @@ import (
 	libpath "github.com/shuLhan/share/lib/path"
 )
 
+func ExampleRoute_IsKeyExists() {
+	var (
+		rute *libpath.Route
+		err  error
+	)
+
+	rute, err = libpath.NewRoute(`/book/:title/:page`)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println(rute.IsKeyExists(`book`))
+	fmt.Println(rute.IsKeyExists(`title`))
+	fmt.Println(rute.IsKeyExists(`TITLE`))
+	// Output:
+	// false
+	// true
+	// true
+}
+
+func ExampleRoute_Keys() {
+	var (
+		rute *libpath.Route
+		err  error
+	)
+
+	rute, err = libpath.NewRoute(`/book/:title/:page`)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println(rute.Keys())
+	// Output:
+	// [title page]
+}
+
+func ExampleRoute_NKey() {
+	var (
+		rute *libpath.Route
+		err  error
+	)
+
+	rute, err = libpath.NewRoute(`/book/:title/:page`)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println(rute.NKey())
+	// Output:
+	// 2
+}
+
 func ExampleRoute_Parse() {
 	var (
 		rute *libpath.Route