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EditorConfig Specification

This is version |version| of this specification.

All content in this document is normative unless marked "(informative)".

EditorConfig helps maintain consistent coding styles for multiple developers working on the same project across various editors and IDEs. The EditorConfig project consists of a file format for defining coding styles and a collection of text editor plugins that enable editors to read the file format and adhere to defined styles. EditorConfig files are easily readable and they work nicely with version control systems.

.. versionchanged:: 0.15.1

In EditorConfig:

  • "EditorConfig files" (usually named .editorconfig) include section(s) storing key-value pairs. EditorConfig files must conform to this specification.
  • "Cores" parse files conforming to this specification, and provide key-value pairs to plugins.
  • "Plugins" receive key-value pairs from cores and update an editor's settings based on the key-value pairs.
  • "Editors" permit editing files, and use plugins to update settings for files being edited.

A conforming core or plugin must pass the tests in the core-tests repository or plugin-tests repository, respectively.

(informative) Some plugins include or bundle their own cores, and some rely on external cores. Some editors include or bundle plugin or core functionality. Editors, plugins, and cores may all come from different people. Those people may or may not have any direct interaction with the EditorConfig organization.

.. versionchanged:: 0.17.2

EditorConfig files are in an INI-like file format. To read an EditorConfig file, take one line at a time, from beginning to end. For each line:

  1. Remove all leading and trailing whitespace.
  2. Process the remaining text as specified for its type below.

The types of lines are:

  • Blank: Contains nothing. Blank lines are ignored.

  • Comment: starts with a ; or a #. Comment lines are ignored.

  • Section Header: starts with a [ and ends with a ]. These lines define globs; see :ref:`glob-expressions`.

    • May contain any characters between the square brackets (e.g., [ and ] and even spaces and tabs are allowed).
    • Forward slashes (/) are used as path separators.
    • Backslashes (\\) are not allowed as path separators (even on Windows).
  • Key-Value Pair (or Pair): contains a key and a value, separated by an =. See :ref:`supported-pairs`.

    • Key: The part before the first = on the line.
    • Value: The part, if any, after the first = on the line.
    • Keys and values are trimmed of leading and trailing whitespace, but include any whitespace that is between non-whitespace characters.
    • If a value is not provided, then the value is an empty string (i.e., "" in C or Python).

Any line that is not one of the above is invalid.

EditorConfig files must be UTF-8 encoded, with LF or CRLF line separators.

.. versionchanged:: 0.15.0

A ; or # anywhere other than at the beginning of a line does not start a comment, but is part of the text of that line. For example:

[*.txt]
foo = editorconfig ;)

gives variable foo the value editorconfig ;) in *.txt files, not the value editorconfig.

This specification does not define any "escaping" mechanism for ; or # characters.

Compatibility

The EditorConfig file format formerly allowed the use of ; and # after the beginning of the line to mark the rest of a line as comment. This led to confusion how to parse values containing those characters. Old EditorConfig parsers may still allow inline comments.

The parts of an EditorConfig file are:

  • Preamble: the lines that precedes the first section. The preamble is optional and may contain key-value pairs, comments and blank lines.
  • Section Name: the string between the beginning [ and the ending ].
  • Section: the lines starting from a Section Header until the beginning of the next Section Header or the end of the file.

Section names in EditorConfig files are filepath globs, similar to the format accepted by .gitignore. They support pattern matching through Unix shell-style wildcards. These filepath globs recognize the following as special characters for wildcard matching:

Special Characters Matching
* any string of characters, except path separators (/)
** any string of characters
? any single character, except path separators (/)
[seq] any single character in seq. Any character inside those brackets is considered literally. It means, that pattern [ab*c{1..2}] is considered literally: either 'a', or 'b', or '*', or 'c', or '{', or '1', or '.', or '2', or '}'.
[!seq] any single character not in seq. Any character inside those brackets is considered literally as well (see example above).
{s1,s2,s3} any of the strings given (separated by commas, can be nested) (But {s1} only matches {s1} literally.)
{num1..num2} any integer numbers between num1 and num2, where num1 and num2 can be either positive or negative. num1 is required to be less than num2. For instance, {1..3}, {-1..4} are valid, but {-4..-5}, {3..1} are not.

If the glob contains a path separator (a / not inside square brackets), then the glob is relative to the directory level of the particular .editorconfig file itself. Otherwise the pattern may also match at any level below the .editorconfig level. For example, *.c matches any file that ends with .c in the directory of .editorconfig or any other directory below one that stores this .editorconfig. However, the glob subdir/*.c only matches files that end with .c in the subdir directory in the directory of .editorconfig.

As a corollary, a section name ending with / does not match any file.

The backslash character (\\) can be used to escape a character so it is not interpreted as a special character.

Cores must accept section names with length up to and including 1024 characters. Beyond that, each implementation may choose to define its own upper limit or no explicit upper limit at all.

When a filename is given to EditorConfig a search is performed in the directory of the given file and all parent directories for an EditorConfig file (named ".editorconfig" by default). Non-existing directories are treated as if they exist and are empty. All found EditorConfig files are searched for sections with section names matching the given filename. The search shall stop if an EditorConfig file is found with the root key set to true in the preamble or when reaching the root filesystem directory.

Files are read top to bottom and the most recent rules found take precedence. If multiple EditorConfig files have matching sections, the rules from the closer EditorConfig file are read last, so pairs in closer files take precedence.

.. versionchanged:: 0.17.1

EditorConfig file sections contain key-value pairs separated by an equal sign (=). With the exception of the root key, all pairs MUST be located under a section to take effect.

  • EditorConfig cores shall accept and report all syntactically valid key-value pairs, even if the key is not defined in this specification.
  • EditorConfig plugins shall ignore unrecognized keys and invalid/unsupported values.

Here is the list of all keys defined by this version of this specification, and the supported values associated with them:

Key Supported values
indent_style Set to tab or space to use tabs or spaces for indentation, respectively. Option tab implies that an indentation is to be filled by as many hard tabs as possible, with the rest of the indentation filled by spaces. A non-normative explanation can be found in the indentation_ section. The values are case insensitive.
indent_size Set to a whole number defining the number of columns used for each indentation level and the width of soft tabs (when supported). If this equals tab, the indent_size shall be set to the tab size, which should be tab_width (if specified); else, the tab size set by the editor. The values are case insensitive.
tab_width Set to a whole number defining the number of columns used to represent a tab character. This defaults to the value of indent_size and should not usually need to be specified.
end_of_line Set to lf, cr, or crlf to control how line breaks are represented. The values are case insensitive.
charset Set to latin1, utf-8, utf-8-bom, utf-16be or utf-16le to control the character set. Use of utf-8-bom is discouraged.
spelling_language

Sets the natural language that should be used for spell checking. Only one language can be specified. There is no default value.

The format is ss or ss-TT, where ss is an ISO 639 two-letter language code and TT is an ISO 3166 two-letter territory identifier. (Therefore spelling_language must be either two or five characters long.)

Note: This property does not specify the charset to be used. The charset is in separate property charset.

trim_trailing_whitespace Set to true to remove all whitespace characters preceding newline characters in the file and false to ensure it doesn't.
insert_final_newline Set to true ensure file ends with a newline when saving and false to ensure it doesn't. Editors must not insert newlines in empty files when saving those files, even if insert_final_newline = true.
root Must be specified in the preamble. Set to true to tell the core not to check any higher directory for EditorConfig settings for on the current filename. The value is case-insensitive.

For any pair, a value of unset removes the effect of that pair, even if it has been set before. For example, add indent_size = unset to undefine the indent_size pair (and use editor defaults).

Pair keys are case insensitive. All keys are lowercased after parsing.

Cores must accept keys and values with lengths up to and including 1024 and 4096 characters respectively. Beyond that, each implementation may choose to define its own upper limits or no explicit upper limits at all.

The indentation related options (indent_style, indent_size and tab_width) require a special documentation section to specify their behavior. Consider the following code snippet:

def execute():
    source = "indentation is important"
    for i in source.split(" "):
        print(i)

The indent_size setting for this code snippet equals 4, because indent_size means how many columns are required to indent the next line in relation to previous (if indentation, of course, is applicable for this line). Then the next question is how this indentation of 4 columns is achieved. It may be 4 consequent spaces/soft tabs, a single tab with width equal to 4, or two tabs with width equal to 2.

This is when indent_style comes into picture. It specifies what character should be used whenever possible in order to achieve the indentation size specified in indent_size. To fully understand what "whenever possible" actually means, lets assume that the editorconfig rules are specified for the file above:

root = true
[example_file.py]
indent_style = tab
indent_size = 4
tab_width = 3

The indent_size of 4 is not achievable by placing 1 or 2 consequent tabs, because tab_width = 3. Therefore, in order to comply with this EditorConfig configuration, the new lines (where indentation is applicable) must be precisely indented with one tab, and one space. That is because by placing one tab we're not achieving the indent_size required, but by placing the 2 consequent tabs we're overreaching. Therefore, although indent_style is tab, we still have to supplement with one space character to fulfill the requirement.

For another example, if we have the following EditorConfig rules defined:

root = true
[another_file.py]
indent_style = tab
indent_size = 8
tab_width = 4

One MUST expect that spaces will not be used at all for indentation, since all the indentation can be achieved via tabs only.

Additionally, it is possible to have indent_size less then the tab_width.

[another_file.py] indent_style = tab indent_size = 4 tab_width = 8

To understand the way it works, let's look at the following example:

def func():
    if True:
        return True

In this case, the line where the if statement condition is specified is indented with 4 spaces, because the indent_size = 4 and the tab cannot fit in. On the other hand, the line with return statement must be indented with one tab, because the indentation level for this line is 8 columns, and a tab can fit in.

TODO. For now please read the Plugin Guidelines on GitHub wiki.

This section applies beginning with version 0.14.0 of this specification.

This specification has a version, tagged in the specification repository. Each specification version corresponds to the same version in the core-tests repository.

The version numbering of the specification follows Semantic Versioning 2.0.0 ("SemVer"). The version numbering of the core-tests repository also follows SemVer.

Each EditorConfig core, to pass the core tests, must process version numbers given with the -b switch, and must report version numbers when given -v or --version. The version numbers used for -b, -v, and --version are versions of this specification. For example, the Vimscript core might respond to -v with:

EditorConfig Vimscript core v1.0.0 - Specification Version 0.14.0

Cores, plugins, or editors supporting EditorConfig have their own version numbers. Those version numbers are independent of the version number of this specification.