Enforce that Ident and Lifetime are well formed
diff --git a/src/ident.rs b/src/ident.rs
index 5d85b48..f93fb43 100644
--- a/src/ident.rs
+++ b/src/ident.rs
@@ -87,7 +87,7 @@
 /// ```
 #[derive(Copy, Clone, Debug)]
 pub struct Ident {
-    pub sym: Term,
+    sym: Term,
     pub span: Span,
 }