Don't overwrite pre-registered primitives in _load_primitives

streaming/stream_sexp_generic.py

@@ -189,7 +189,10 @@ class StreamInterpreter:
                 prim_name = name[5:]
                 dash_name = prim_name.replace('_', '-')
                 # Register ONLY with namespace (geometry:ripple-displace)
-                self.primitives[f"{lib_name}:{dash_name}"] = func
+                # Don't overwrite if already registered (allows pre-registration of overrides)
+                key = f"{lib_name}:{dash_name}"
+                if key not in self.primitives:
+                    self.primitives[key] = func
                 count += 1
 
         if hasattr(module, 'PRIMITIVES'):
@@ -197,9 +200,12 @@ class StreamInterpreter:
             if isinstance(prims, dict):
                 for name, func in prims.items():
                     # Register ONLY with namespace
+                    # Don't overwrite if already registered
                     dash_name = name.replace('_', '-')
-                    self.primitives[f"{lib_name}:{dash_name}"] = func
-                    count += 1
+                    key = f"{lib_name}:{dash_name}"
+                    if key not in self.primitives:
+                        self.primitives[key] = func
+                        count += 1
 
         print(f"Loaded primitives: {lib_name} ({count} functions)", file=sys.stderr)