Move test for g:load_black to improve plugin performance (GH-2896)

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

diff --git a/docs/the_black_code_style/current_style.md b/docs/the_black_code_style/current_style.md
index aa2dd881a9ea8a520673a9eb951b3844489c66d5..0bf5894abdd6202d9298738f79d00c1b26e689d3 100644 (file)
--- a/docs/the_black_code_style/current_style.md
+++ b/docs/the_black_code_style/current_style.md
@@ -2,20 +2,27 @@
 
 ## Code style
 
 
 ## Code style
 

-_Black_ reformats entire files in place. Style configuration options are deliberately
-limited and rarely added. It doesn't take previous formatting into account, except for
-the magic trailing comma and preserving newlines. It doesn't reformat blocks that start
-with `# fmt: off` and end with `# fmt: on`, or lines that ends with `# fmt: skip`.
+_Black_ aims for consistency, generality, readability and reducing git diffs. Similar
+language constructs are formatted with similar rules. Style configuration options are
+deliberately limited and rarely added. Previous formatting is taken into account as
+little as possible, with rare exceptions like the magic trailing comma. The coding style
+used by _Black_ can be viewed as a strict subset of PEP 8.
+
+_Black_ reformats entire files in place. It doesn't reformat blocks that start with
+`# fmt: off` and end with `# fmt: on`, or lines that ends with `# fmt: skip`.

 `# fmt: on/off` have to be on the same level of indentation. It also recognizes
 [YAPF](https://github.com/google/yapf)'s block comments to the same effect, as a
 courtesy for straddling code.
 
 `# fmt: on/off` have to be on the same level of indentation. It also recognizes
 [YAPF](https://github.com/google/yapf)'s block comments to the same effect, as a
 courtesy for straddling code.
 

+The rest of this document describes the current formatting style. If you're interested
+in trying out where the style is heading, see [future style](./future_style.md) and try
+running `black --preview`.
+

 ### How _Black_ wraps lines
 
 _Black_ ignores previous formatting and applies uniform horizontal and vertical
 whitespace to your code. The rules for horizontal whitespace can be summarized as: do
 ### How _Black_ wraps lines
 
 _Black_ ignores previous formatting and applies uniform horizontal and vertical
 whitespace to your code. The rules for horizontal whitespace can be summarized as: do

-whatever makes `pycodestyle` happy. The coding style used by _Black_ can be viewed as a
-strict subset of PEP 8.
+whatever makes `pycodestyle` happy.

 
 As for vertical whitespace, _Black_ tries to render one full expression or simple
 statement per line. If this fits the allotted line length, great.
 
 As for vertical whitespace, _Black_ tries to render one full expression or simple
 statement per line. If this fits the allotted line length, great.


@@ -233,10 +240,10 @@ _Black_ prefers double quotes (`"` and `"""`) over single quotes (`'` and `'''`)
 will replace the latter with the former as long as it does not result in more backslash
 escapes than before.
 
 will replace the latter with the former as long as it does not result in more backslash
 escapes than before.
 

-_Black_ also standardizes string prefixes, making them always lowercase. On top of that,
-if your code is already Python 3.6+ only or it's using the `unicode_literals` future
-import, _Black_ will remove `u` from the string prefix as it is meaningless in those
-scenarios.
+_Black_ also standardizes string prefixes. Prefix characters are made lowercase with the
+exception of [capital "R" prefixes](#rstrings-and-rstrings), unicode literal markers
+(`u`) are removed because they are meaningless in Python 3, and in the case of multiple
+characters "r" is put first as in spoken language: "raw f-string".

 
 The main reason to standardize on a single form of quotes is aesthetics. Having one kind
 of quotes everywhere reduces reader distraction. It will also enable a future version of
 
 The main reason to standardize on a single form of quotes is aesthetics. Having one kind
 of quotes everywhere reduces reader distraction. It will also enable a future version of


@@ -260,29 +267,18 @@ If you are adopting _Black_ in a large project with pre-existing string conventi
 you can pass `--skip-string-normalization` on the command line. This is meant as an
 adoption helper, avoid using this for new projects.
 
 you can pass `--skip-string-normalization` on the command line. This is meant as an
 adoption helper, avoid using this for new projects.
 

-(labels/experimental-string)=
-
-As an experimental option (can be enabled by `--experimental-string-processing`),
-_Black_ splits long strings (using parentheses where appropriate) and merges short ones.
-When split, parts of f-strings that don't need formatting are converted to plain
-strings. User-made splits are respected when they do not exceed the line length limit.
-Line continuation backslashes are converted into parenthesized strings. Unnecessary
-parentheses are stripped. Because the functionality is experimental, feedback and issue
-reports are highly encouraged!
-

 _Black_ also processes docstrings. Firstly the indentation of docstrings is corrected
 for both quotations and the text within, although relative indentation in the text is
 preserved. Superfluous trailing whitespace on each line and unnecessary new lines at the
 end of the docstring are removed. All leading tabs are converted to spaces, but tabs
 inside text are preserved. Whitespace leading and trailing one-line docstrings is
 _Black_ also processes docstrings. Firstly the indentation of docstrings is corrected
 for both quotations and the text within, although relative indentation in the text is
 preserved. Superfluous trailing whitespace on each line and unnecessary new lines at the
 end of the docstring are removed. All leading tabs are converted to spaces, but tabs
 inside text are preserved. Whitespace leading and trailing one-line docstrings is

-removed. The quotations of an empty docstring are separated with one space.
+removed.

 
 ### Numeric literals
 
 _Black_ standardizes most numeric literals to use lowercase letters for the syntactic
 parts and uppercase letters for the digits themselves: `0xAB` instead of `0XAB` and
 
 ### Numeric literals
 
 _Black_ standardizes most numeric literals to use lowercase letters for the syntactic
 parts and uppercase letters for the digits themselves: `0xAB` instead of `0XAB` and

-`1e10` instead of `1E10`. Python 2 long literals are styled as `2L` instead of `2l` to
-avoid confusion between `l` and `1`.
+`1e10` instead of `1E10`.

 
 ### Line breaks & binary operators
 
 
 ### Line breaks & binary operators
 


@@ -291,6 +287,26 @@ multiple lines. This is so that _Black_ is compliant with the recent changes in
 [PEP 8](https://www.python.org/dev/peps/pep-0008/#should-a-line-break-before-or-after-a-binary-operator)
 style guide, which emphasizes that this approach improves readability.
 
 [PEP 8](https://www.python.org/dev/peps/pep-0008/#should-a-line-break-before-or-after-a-binary-operator)
 style guide, which emphasizes that this approach improves readability.
 

+Almost all operators will be surrounded by single spaces, the only exceptions are unary
+operators (`+`, `-`, and `~`), and power operators when both operands are simple. For
+powers, an operand is considered simple if it's only a NAME, numeric CONSTANT, or
+attribute access (chained attribute access is allowed), with or without a preceding
+unary operator.
+
+```python
+# For example, these won't be surrounded by whitespace
+a = x**y
+b = config.base**5.2
+c = config.base**runtime.config.exponent
+d = 2**5
+e = 2**~5
+
+# ... but these will be surrounded by whitespace
+f = 2 ** get_exponent()
+g = get_x() ** get_y()
+h = config['base'] ** 2
+```
+

 ### Slices
 
 PEP 8
 ### Slices
 
 PEP 8