feat: figured out starmelon needs expr types

To generate partial application boxed closures I need to know the arity
of the expression to tell if more args will remain after the given args.
Right now I think I can recalculate the types if I have a symbol table
where I can look up every variable. I think this will be a lot of work
because I have to reimplement most of unification to deal with
collections, patterns, and type variables. And I currently don't know
how unification works.

src/elm.rs

@@ -68,7 +68,12 @@ pub fn load_interfaces(
                             elmi::DependencyInterface::Public(interface) => {
                                 interfaces.insert(module_name, interface);
                             }
-                            _ => {}
+                            elmi::DependencyInterface::Private(package_name, unions, aliases) => {
+                                println!("skipping private interface {}", package_name);
+                                //for (k, v) in unions {
+                                //    println!("  {}", k);
+                                //}
+                            }
                         }
                     }
                 }