graingert · May 12, 2025 06:45 · May 12, 2025
diff --git a/demo.py b/demo.py
@@ -0,0 +1,107 @@
+import sys
+from typing import Self, cast
+import dataclasses
+
+@dataclasses.dataclass(slots=False)
+class Node:
+    _parent: Self | None
+
+MessagePump = Node
+DOMNode = Node
+
+
+def mk_nodes():
+    node = Node(None)
+    for i in range(1000000):
+        node = Node(node)
+
+    return node
+
+def ancestors_with_self_traditional(self):
+    nodes = []
+    node: Node | None = self
+
+    while node is not None:
+        nodes.append(node)
+        node = node._parent
+
+    return nodes
+
+def ancestors_with_self_traditional_while_true_invert_cond_return(self):
+    nodes = []
+    node: Node | None = self
+
+    while True:
+        if node is None:
+            return nodes
+
+        nodes.append(node)
+        node = node._parent
+
+
+def ancestors_with_self_traditional_while_true_invert_cond_break(self):
+    nodes = []
+    node: Node | None = self
+
+    while True:
+        if node is None:
+            break
+
+        nodes.append(node)
+        node = node._parent
+
+    return nodes
+
+
+def ancestors_with_self_traditional_while_true_break(self):
+    nodes = []
+    node: Node | None = self
+
+    while True:
+        if node is not None:
+            nodes.append(node)
+            node = node._parent
+        else:
+            break
+
+    return nodes
+
+def ancestors_with_self_traditional_while_true_return(self):
+    nodes = []
+    node: Node | None = self
+
+    while True:
+        if node is not None:
+            nodes.append(node)
+            node = node._parent
+        else:
+            return nodes
+
+    return nodes
+
+
+
+
+import pyperf
+
+def main():
+    runner = pyperf.Runner()
+    runner.timeit(name="flatten a linked list tradition",
+                  stmt="demo.ancestors_with_self_traditional(nodes)",
+                  setup="import demo; nodes = demo.mk_nodes()")
+    runner.timeit(name="flatten a linked list tradition while true, invert cond (return)",
+                  stmt="demo.ancestors_with_self_traditional_while_true_invert_cond_return(nodes)",
+                  setup="import demo; nodes = demo.mk_nodes()")
+    runner.timeit(name="flatten a linked list tradition while true, invert cond (break)",
+                  stmt="demo.ancestors_with_self_traditional_while_true_invert_cond_break(nodes)",
+                  setup="import demo; nodes = demo.mk_nodes()")
+    runner.timeit(name="flatten a linked list tradition while true, (break)",
+                  stmt="demo.ancestors_with_self_traditional_while_true_break(nodes)",
+                  setup="import demo; nodes = demo.mk_nodes()")
+    runner.timeit(name="flatten a linked list tradition while true, (return)",
+                  stmt="demo.ancestors_with_self_traditional_while_true_return(nodes)",
+                  setup="import demo; nodes = demo.mk_nodes()")
+
+
+if __name__ == "__main__":
+    sys.exit(main())