Clean up monkey.fix.step

1 files changed, 5 insertions, 0 deletions

diff --git a/monkey/edits.py b/monkey/edits.py
index 480af5f..bf6560d 100644
--- a/monkey/edits.py
+++ b/monkey/edits.py
@@ -194,6 +194,11 @@ def get_edits_from_traces(traces):
                 start = normalize(path[i-1], var_names)
                 end = normalize(path[i], var_names)
 
+                # Disallow edits that insert a whole rule (a → … :- …).
+                # TODO improve edit_graph to handle this.
+                if 'FROM' in [t.type for t in end[:-1]]:
+                    continue
+
                 # This should always succeed but check anyway.
                 if start != end:
                     edit = (start, end)