protect imported predicates from being overwritten (re: issue #28)

2018-04-23 15:55:53 -06:00
parent b87d599b14
commit a891b9327c
2 changed files with 3 additions and 5 deletions
--- a/src/prolog/machine/mod.rs
+++ b/src/prolog/machine/mod.rs
@@ -190,12 +190,10 @@ impl Machine {
                         -> EvalSession
    {
        match self.code_dir.get(&(name.clone(), arity)) {
-            Some(&CodeIndex (ref idx)) =>
-                if idx.borrow().1 == clause_name!("builtin") {
+            Some(&CodeIndex (ref idx)) if idx.borrow().1 != clause_name!("user") =>
                    return EvalSession::from(EvalError::ImpermissibleEntry(format!("{}/{}",
                                                                                   name,
-                                                                                   arity)))
-                },
+                                                                                   arity))),                
            _ => {}
        };