Avoid recompiling the implementation of many0 so much
diff --git a/src/file.rs b/src/file.rs
index fd3d5b2..fe06958 100644
--- a/src/file.rs
+++ b/src/file.rs
@@ -16,8 +16,8 @@
 
     impl Synom for File {
         named!(parse -> Self, do_parse!(
-            attrs: many0!(call!(Attribute::parse_inner)) >>
-            items: many0!(syn!(Item)) >>
+            attrs: many0!(Attribute::parse_inner) >>
+            items: many0!(Item::parse) >>
             (File {
                 shebang: None,
                 attrs: attrs,