some fixes

src/lib.rs

@@ -105,14 +105,22 @@ impl App {
 /// `$($Ident: $Path,)*`
 pub type Crcs = HashMap<Ident, Path>;
 
+/// Input port binding
+#[derive(Debug)]
 pub enum IpTo {
+    /// Input port connecting to inner Crc
     Crc(Path),
+    /// Input port connecting to method
     Method(Ident),
 }
 
+///
+#[derive(Debug)]
 pub struct Ip {
+    /// Input port type
     ty: Ty,
-    to: IpBind,
+    /// Input port binding
+    to: IpTo,
 }
 
 /// `$($Ident: $Ty,)*`