Implement path extractor (#124)

Fixes #42

examples/key_value_store.rs

@@ -8,7 +8,7 @@
 
 use axum::{
     async_trait,
-    extract::{extractor_middleware, ContentLengthLimit, Extension, RequestParts, UrlParams},
+    extract::{extractor_middleware, ContentLengthLimit, Extension, Path, RequestParts},
     prelude::*,
     response::IntoResponse,
     routing::BoxRoute,
@@ -79,7 +79,7 @@ struct State {
 }
 
 async fn kv_get(
-    UrlParams((key,)): UrlParams<(String,)>,
+    Path(key): Path<String>,
     Extension(state): Extension<SharedState>,
 ) -> Result<Bytes, StatusCode> {
     let db = &state.read().unwrap().db;
@@ -92,7 +92,7 @@ async fn kv_get(
 }
 
 async fn kv_set(
-    UrlParams((key,)): UrlParams<(String,)>,
+    Path(key): Path<String>,
     ContentLengthLimit(bytes): ContentLengthLimit<Bytes, { 1024 * 5_000 }>, // ~5mb
     Extension(state): Extension<SharedState>,
 ) {
@@ -113,10 +113,7 @@ fn admin_routes() -> BoxRoute<hyper::Body> {
         state.write().unwrap().db.clear();
     }
 
-    async fn remove_key(
-        UrlParams((key,)): UrlParams<(String,)>,
-        Extension(state): Extension<SharedState>,
-    ) {
+    async fn remove_key(Path(key): Path<String>, Extension(state): Extension<SharedState>) {
         state.write().unwrap().db.remove(&key);
     }