X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/c4bd2e31ceeac84d68592986fe70920f3d3d0443..882d8795c6ff65c02f2657e596391748d1b6b7f5:/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 6d289d4..367ff98 100644
--- a/docs/the_black_code_style/future_style.md
+++ b/docs/the_black_code_style/future_style.md
@@ -47,11 +47,13 @@ with contextlib.ExitStack() as exit_stack:
     ...
 ```
 
+(labels/preview-style)=
+
 ## Preview style
 
 Experimental, potentially disruptive style changes are gathered under the `--preview`
 CLI flag. At the end of each year, these changes may be adopted into the default style,
-as described in [The Black Code Style](./index.rst). Because the functionality is
+as described in [The Black Code Style](index.md). Because the functionality is
 experimental, feedback and issue reports are highly encouraged!
 
 ### Improved string processing
@@ -62,3 +64,163 @@ plain strings. User-made splits are respected when they do not exceed the line l
 limit. Line continuation backslashes are converted into parenthesized strings.
 Unnecessary parentheses are stripped. The stability and status of this feature is
 tracked in [this issue](https://github.com/psf/black/issues/2188).
+
+### Improved line breaks
+
+For assignment expressions, _Black_ now prefers to split and wrap the right side of the
+assignment instead of left side. For example:
+
+```python
+some_dict[
+    "with_a_long_key"
+] = some_looooooooong_module.some_looooooooooooooong_function_name(
+    first_argument, second_argument, third_argument
+)
+```
+
+will be changed to:
+
+```python
+some_dict["with_a_long_key"] = (
+    some_looooooooong_module.some_looooooooooooooong_function_name(
+        first_argument, second_argument, third_argument
+    )
+)
+```
+
+### Improved parentheses management
+
+For dict literals with long values, they are now wrapped in parentheses. Unnecessary
+parentheses are now removed. For example:
+
+```python
+my_dict = {
+    "a key in my dict": a_very_long_variable
+    * and_a_very_long_function_call()
+    / 100000.0,
+    "another key": (short_value),
+}
+```
+
+will be changed to:
+
+```python
+my_dict = {
+    "a key in my dict": (
+        a_very_long_variable * and_a_very_long_function_call() / 100000.0
+    ),
+    "another key": short_value,
+}
+```
+
+### Improved multiline string handling
+
+_Black_ is smarter when formatting multiline strings, especially in function arguments,
+to avoid introducing extra line breaks. Previously, it would always consider multiline
+strings as not fitting on a single line. With this new feature, _Black_ looks at the
+context around the multiline string to decide if it should be inlined or split to a
+separate line. For example, when a multiline string is passed to a function, _Black_
+will only split the multiline string if a line is too long or if multiple arguments are
+being passed.
+
+For example, _Black_ will reformat
+
+```python
+textwrap.dedent(
+    """\
+    This is a
+    multiline string
+"""
+)
+```
+
+to:
+
+```python
+textwrap.dedent("""\
+    This is a
+    multiline string
+""")
+```
+
+And:
+
+```python
+MULTILINE = """
+foobar
+""".replace(
+    "\n", ""
+)
+```
+
+to:
+
+```python
+MULTILINE = """
+foobar
+""".replace("\n", "")
+```
+
+Implicit multiline strings are special, because they can have inline comments. Strings
+without comments are merged, for example
+
+```python
+s = (
+    "An "
+    "implicit "
+    "multiline "
+    "string"
+)
+```
+
+becomes
+
+```python
+s = "An implicit multiline string"
+```
+
+A comment on any line of the string (or between two string lines) will block the
+merging, so
+
+```python
+s = (
+    "An "  # Important comment concerning just this line
+    "implicit "
+    "multiline "
+    "string"
+)
+```
+
+and
+
+```python
+s = (
+    "An "
+    "implicit "
+    # Comment in between
+    "multiline "
+    "string"
+)
+```
+
+will not be merged. Having the comment after or before the string lines (but still
+inside the parens) will merge the string. For example
+
+```python
+s = (  # Top comment
+    "An "
+    "implicit "
+    "multiline "
+    "string"
+    # Bottom comment
+)
+```
+
+becomes
+
+```python
+s = (  # Top comment
+    "An implicit multiline string"
+    # Bottom comment
+)
+```