Memoize route match selector

#performance

package.json

@@ -69,6 +69,7 @@
     "querystringify": "^1.0.0",
     "redux": "^3.6.0",
     "refx": "^2.0.0",
+    "rememo": "^1.0.0",
     "shallow-equal": "^1.0.0",
     "textarea-caret": "^3.0.2"
   }

src/state/selectors/get-matched-route.js

@@ -1,6 +1,7 @@
 /**
  * External dependencies
  */
+import createSelector from 'rememo';
 import { parse } from 'querystringify';
 
 /**
@@ -9,28 +10,31 @@ import { parse } from 'querystringify';
 import routes from 'routes';
 import { getRoutePath } from './';
 
-export default function getMatchedRoute( state ) {
-	const path = getRoutePath( state );
-	const [ pathname, search = '' ] = path.split( '?' );
+export default createSelector(
+	( state ) => {
+		const path = getRoutePath( state );
+		const [ pathname, search = '' ] = path.split( '?' );
 
-	for ( let r = 0, rl = routes.length; r < rl; r++ ) {
-		const { regexp, keys, Route } = routes[ r ];
-		const match = pathname.match( regexp );
-		if ( ! match ) {
-			continue;
-		}
+		for ( let r = 0, rl = routes.length; r < rl; r++ ) {
+			const { regexp, keys, Route } = routes[ r ];
+			const match = pathname.match( regexp );
+			if ( ! match ) {
+				continue;
+			}
 
-		const params = {};
-		for ( let m = 1, ml = match.length; m < ml; m++ ) {
-			params[ keys[ m - 1 ].name ] = decodeURIComponent( match[ m ] );
-		}
+			const params = {};
+			for ( let m = 1, ml = match.length; m < ml; m++ ) {
+				params[ keys[ m - 1 ].name ] = decodeURIComponent( match[ m ] );
+			}
 
-		return {
-			params,
-			Route,
-			query: parse( search )
-		};
-	}
+			return {
+				params,
+				Route,
+				query: parse( search )
+			};
+		}
 
-	return {};
-}
+		return {};
+	},
+	( state ) => getRoutePath( state )
+);