Fix import of blib2to3.pgen2.driver (#3546)

[etc/vim.git] / docs / the_black_code_style / future_style.md

diff --git a/docs/the_black_code_style/future_style.md b/docs/the_black_code_style/future_style.md
index 2ec2c0333a5fb3a1db077c20f74578956ef20739..6d289d460a76c10db74343e991f3dfc26e075ab7 100644 (file)
--- a/docs/the_black_code_style/future_style.md
+++ b/docs/the_black_code_style/future_style.md
@@ -19,20 +19,33 @@ with make_context_manager1() as cm1, make_context_manager2() as cm2, make_contex
     ...  # nothing to split on - line too long
 ```
 
-So _Black_ will eventually format it like this:
+So _Black_ will, when we implement this, format it like this:
 
 ```py3
 with \
-     make_context_manager(1) as cm1, \
-     make_context_manager(2) as cm2, \
-     make_context_manager(3) as cm3, \
-     make_context_manager(4) as cm4 \
+     make_context_manager1() as cm1, \
+     make_context_manager2() as cm2, \
+     make_context_manager3() as cm3, \
+     make_context_manager4() as cm4 \
 :
     ...  # backslashes and an ugly stranded colon
 ```
 
-Although when the target version is Python 3.9 or higher, _Black_ will use parentheses
-instead since they're allowed in Python 3.9 and higher.
+Although when the target version is Python 3.9 or higher, _Black_ uses parentheses
+instead in `--preview` mode (see below) since they're allowed in Python 3.9 and higher.
+
+An alternative to consider if the backslashes in the above formatting are undesirable is
+to use {external:py:obj}`contextlib.ExitStack` to combine context managers in the
+following way:
+
+```python
+with contextlib.ExitStack() as exit_stack:
+    cm1 = exit_stack.enter_context(make_context_manager1())
+    cm2 = exit_stack.enter_context(make_context_manager2())
+    cm3 = exit_stack.enter_context(make_context_manager3())
+    cm4 = exit_stack.enter_context(make_context_manager4())
+    ...
+```
 
 ## Preview style