Micro optimize generate_legal_moves

surya-veer · Mar 6, 2017 · 5e3df3f · 5e3df3f
1 parent 3cd6f65
commit 5e3df3f
Showing 1 changed file with 9 additions and 6 deletions.
diff --git a/chess/__init__.py b/chess/__init__.py
@@ -3210,15 +3210,18 @@ def _generate_evasions(self, from_mask=BB_ALL, to_mask=BB_ALL):
                 yield move
 
     def generate_legal_moves(self, from_mask=BB_ALL, to_mask=BB_ALL):
+        blockers = self._slider_blockers()
+
         if self.is_variant_end():
-            moves = []
+            return
         elif self.is_check():
-            moves = self._generate_evasions(from_mask, to_mask)
+            for move in self._generate_evasions(from_mask, to_mask):
+                if self._is_safe(blockers, move):
+                    yield move
         else:
-            moves = self.generate_pseudo_legal_moves(from_mask, to_mask)
-
-        blockers = self._slider_blockers()
-        return (move for move in moves if self._is_safe(blockers, move))
+            for move in self.generate_pseudo_legal_moves(from_mask, to_mask):
+                if self._is_safe(blockers, move):
+                    yield move
 
     def generate_legal_ep(self, from_mask=BB_ALL, to_mask=BB_ALL):
         if self.is_variant_end():