将 layout.jade 中的 JS 抽取到 layout.coffee

core/static/script/layout.coffee

@@ -0,0 +1,4 @@
+$ ->
+  $('nav a').each (index) ->
+    if $('nav a')[index].pathname == location.pathname
+      $($('nav a')[index]).parent().addClass('active')

core/view/layout.jade

@@ -46,10 +46,4 @@ html
     #footer
       script(src='http://cdn.staticfile.org/jquery/2.0.3/jquery.min.js')
       script(src='http://cdn.staticfile.org/twitter-bootstrap/3.0.0-rc2/js/bootstrap.min.js')
-      script.
-        $(function() {
-          $('nav a').each(function(index) {
-            if($('nav a')[index].pathname == location.pathname)
-              $($('nav a')[index]).parent().addClass('active')
-          });
-        });
+      script(src='/script/layout.js')