Definitions can only come from the same or a parent namespace

This commit fixes an error where a reference was being resolved by a
definition in a child namespace.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/source_unit.rs b/src/source_unit.rs
index bc6d4ab..1581b58 100644
--- a/src/source_unit.rs
+++ b/src/source_unit.rs
@@ -119,6 +119,7 @@ impl Symbol {
     /// True if this symbol is a valid definition for a reference symbol
     pub fn defines(&self, reference: &Symbol) -> bool {
         self.name == reference.name &&
+        self.namespace.len() <= reference.namespace.len() &&
         std::iter::zip(&self.namespace, &reference.namespace).all(|(a, b)| a == b)
     }
 }