tree_all: add support for is_leaf

Author: jakevdp

CHANGELOG.md

@@ -18,6 +18,7 @@ Remember to align the itemized text with the first line of an item within a list
     `from jax.experimental.export import export`, and instead you should use
     `from jax.experimental import export`.
     The removed functionality has been deprecated since 0.4.24.
+  * Added `is_leaf` argument to {func}`jax.tree.all` & {func}`jax.tree_util.tree_all`.
 
 * Deprecations
   * `jax.sharding.XLACompatibleSharding` is deprecated. Please use

jax/_src/tree.py

@@ -20,9 +20,9 @@
 T = TypeVar("T")
 
 
-def all(tree: Any) -> bool:
+def all(tree: Any, *, is_leaf: Callable[[Any], bool] | None = None) -> bool:
   """Alias of :func:`jax.tree_util.tree_all`."""
-  return tree_util.tree_all(tree)
+  return tree_util.tree_all(tree, is_leaf=is_leaf)
 
 
 def flatten(tree: Any,

jax/_src/tree_util.py

@@ -623,11 +623,15 @@ def tree_reduce(function: Callable[[T, Any], T],
 
 
 @export
-def tree_all(tree: Any) -> bool:
+def tree_all(tree: Any, *, is_leaf: Callable[[Any], bool] | None = None) -> bool:
   """Call all() over the leaves of a tree.
 
   Args:
     tree: the pytree to evaluate
+    is_leaf : an optionally specified function that will be called at each
+      flattening step. It should return a boolean, which indicates whether the
+      flattening should traverse the current object, or if it should be stopped
+      immediately, with the whole subtree being treated as a leaf.
 
   Returns:
     result: boolean True or False
@@ -643,7 +647,7 @@ def tree_all(tree: Any) -> bool:
     - :func:`jax.tree_util.tree_reduce`
     - :func:`jax.tree_util.tree_leaves`
   """
-  return all(tree_leaves(tree))
+  return all(tree_leaves(tree, is_leaf=is_leaf))
 
 
 register_pytree_node(

tests/tree_util_test.py

@@ -1153,20 +1153,44 @@ def test_tree_all(self):
       tree_util.tree_all(obj),
     )
 
+  def test_tree_all_is_leaf(self):
+    obj = [True, True, (True, False)]
+    is_leaf = lambda x: isinstance(x, tuple)
+    self.assertEqual(
+      jax.tree.all(obj, is_leaf=is_leaf),
+      tree_util.tree_all(obj, is_leaf=is_leaf),
+    )
+
   def test_tree_flatten(self):
     obj = [1, 2, (3, 4)]
     self.assertEqual(
       jax.tree.flatten(obj),
       tree_util.tree_flatten(obj),
     )
 
+  def test_tree_flatten_is_leaf(self):
+    obj = [1, 2, (3, 4)]
+    is_leaf = lambda x: isinstance(x, tuple)
+    self.assertEqual(
+      jax.tree.flatten(obj, is_leaf=is_leaf),
+      tree_util.tree_flatten(obj, is_leaf=is_leaf),
+    )
+
   def test_tree_leaves(self):
     obj = [1, 2, (3, 4)]
     self.assertEqual(
       jax.tree.leaves(obj),
       tree_util.tree_leaves(obj),
     )
 
+  def test_tree_leaves_is_leaf(self):
+    obj = [1, 2, (3, 4)]
+    is_leaf = lambda x: isinstance(x, tuple)
+    self.assertEqual(
+      jax.tree.leaves(obj, is_leaf=is_leaf),
+      tree_util.tree_leaves(obj, is_leaf=is_leaf),
+    )
+
   def test_tree_map(self):
     func = lambda x: x * 2
     obj = [1, 2, (3, 4)]
@@ -1175,6 +1199,15 @@ def test_tree_map(self):
       tree_util.tree_map(func, obj),
     )
 
+  def test_tree_map_is_leaf(self):
+    func = lambda x: x * 2
+    obj = [1, 2, (3, 4)]
+    is_leaf = lambda x: isinstance(x, tuple)
+    self.assertEqual(
+      jax.tree.map(func, obj, is_leaf=is_leaf),
+      tree_util.tree_map(func, obj, is_leaf=is_leaf),
+    )
+
   def test_tree_reduce(self):
     func = lambda a, b: a + b
     obj = [1, 2, (3, 4)]
@@ -1183,13 +1216,30 @@ def test_tree_reduce(self):
       tree_util.tree_reduce(func, obj),
     )
 
+  def test_tree_reduce_is_leaf(self):
+    func = lambda a, b: a + b
+    obj = [(1, 2), (3, 4)]
+    is_leaf = lambda x: isinstance(x, tuple)
+    self.assertEqual(
+      jax.tree.reduce(func, obj, is_leaf=is_leaf),
+      tree_util.tree_reduce(func, obj, is_leaf=is_leaf),
+    )
+
   def test_tree_structure(self):
     obj = [1, 2, (3, 4)]
     self.assertEqual(
       jax.tree.structure(obj),
       tree_util.tree_structure(obj),
     )
 
+  def test_tree_structure_is_leaf(self):
+    obj = [1, 2, (3, 4)]
+    is_leaf = lambda x: isinstance(x, tuple)
+    self.assertEqual(
+      jax.tree.structure(obj, is_leaf=is_leaf),
+      tree_util.tree_structure(obj, is_leaf=is_leaf),
+    )
+
   def test_tree_transpose(self):
     obj = [(1, 2), (3, 4), (5, 6)]
     outer_treedef = tree_util.tree_structure(['*', '*', '*'])