Improve the replicate_quantified

The mutator is improved by ensuring to replicate non-empty subtrees
only and instead of inserting a single copy, a random number of
replicant will be added that still obeys the quantifier restrictions.

grammarinator/tool/generator.py

@@ -528,10 +528,12 @@ def replicate_quantified(self, individual=None, _=None):
         root_options = [node for node in annot.quants if node.stop > len(node.children)]
         recipient_root_token_counts = annot.token_counts[root]
         node_options = [child for root in root_options for child in root.children if
-                        recipient_root_token_counts + annot.token_counts[child] <= self._limit.tokens]
+                        recipient_root_token_counts < recipient_root_token_counts + annot.token_counts[child] <= self._limit.tokens]
         if node_options:
             node_to_repeat = random.choice(node_options)
-            node_to_repeat.parent.insert_child(idx=random.randint(0, len(node_to_repeat.parent.children)), node=deepcopy(node_to_repeat))
+            max_repeat = (self._limit.tokens - recipient_root_token_counts) // annot.token_counts[node_to_repeat]
+            for _ in range(random.randint(1, max_repeat)):
+                node_to_repeat.parent.insert_child(idx=random.randint(0, len(node_to_repeat.parent.children)), node=deepcopy(node_to_repeat))
 
         # Return with the original root, whether the replication was successful or not.
         return root