ale/doc/ale.txt

*ale.txt*  For Vim version 8.0.
*ale*

ALE - Asynchronous Lint Engine

===============================================================================
CONTENTS                                                         *ale-contents*

  1. Introduction.........................|ale-introduction|
  2. Supported Languages & Tools..........|ale-support|
  3. Global Options.......................|ale-options|
  4. Fixing Problems......................|ale-fix|
  5. Integration Documentation............|ale-integrations|
    asm...................................|ale-asm-options|
      gcc.................................|ale-asm-gcc|
    c.....................................|ale-c-options|
      clang...............................|ale-c-clang|
      cppcheck............................|ale-c-cppcheck|
      gcc.................................|ale-c-gcc|
    chef..................................|ale-chef-options|
      foodcritic..........................|ale-chef-foodcritic|
    cpp...................................|ale-cpp-options|
      clang...............................|ale-cpp-clang|
      clangtidy...........................|ale-cpp-clangtidy|
      cppcheck............................|ale-cpp-cppcheck|
      cpplint.............................|ale-cpp-cpplint|
      gcc.................................|ale-cpp-gcc|
    css...................................|ale-css-options|
      stylelint...........................|ale-css-stylelint|
    cmake.................................|ale-cmake-options|
      cmakelint...........................|ale-cmake-cmakelint|
    erlang................................|ale-erlang-options|
      erlc................................|ale-erlang-erlc|
    fortran...............................|ale-fortran-options|
      gcc.................................|ale-fortran-gcc|
    go....................................|ale-go-options|
      gometalinter........................|ale-go-gometalinter|
    handlebars............................|ale-handlebars-options|
      ember-template-lint.................|ale-handlebars-embertemplatelint|
    html..................................|ale-html-options|
      htmlhint............................|ale-html-htmlhint|
      tidy................................|ale-html-tidy|
    java..................................|ale-java-options|
      checkstyle..........................|ale-java-checkstyle|
      javac...............................|ale-java-javac|
    javascript............................|ale-javascript-options|
      eslint..............................|ale-javascript-eslint|
      flow................................|ale-javascript-flow|
      jshint..............................|ale-javascript-jshint|
      prettier............................|ale-javascript-prettier|
      prettier-eslint.....................|ale-javascript-prettier-eslint|
      standard............................|ale-javascript-standard|
      xo..................................|ale-javascript-xo|
    kotlin................................|ale-kotlin-options|
      kotlinc.............................|ale-kotlin-kotlinc|
    lua...................................|ale-lua-options|
      luacheck............................|ale-lua-luacheck|
    objc..................................|ale-objc-options|
      clang...............................|ale-objc-clang|
    objcpp................................|ale-objcpp-options|
      clang...............................|ale-objcpp-clang|
    ocaml.................................|ale-ocaml-options|
      merlin..............................|ale-ocaml-merlin|
    perl..................................|ale-perl-options|
      perl................................|ale-perl-perl|
    php...................................|ale-php-options|
      phpcs...............................|ale-php-phpcs|
      phpmd...............................|ale-php-phpmd|
    python................................|ale-python-options|
      flake8..............................|ale-python-flake8|
      mypy................................|ale-python-mypy|
      pylint..............................|ale-python-pylint|
    ruby..................................|ale-ruby-options|
      reek................................|ale-ruby-reek|
      rubocop.............................|ale-ruby-rubocop|
    rust..................................|ale-rust-options|
      cargo...............................|ale-rust-cargo|
      rustc...............................|ale-rust-rustc|
    sass..................................|ale-sass-options|
      stylelint...........................|ale-sass-stylelint|
    scss..................................|ale-scss-options|
      stylelint...........................|ale-scss-stylelint|
    sh....................................|ale-sh-options|
      shell...............................|ale-sh-shell|
      shellcheck..........................|ale-sh-shellcheck|
    spec..................................|ale-spec-options|
      rpmlint.............................|ale-spec-rpmlint|
    tex...................................|ale-tex-options|
      chktex..............................|ale-tex-chktex|
      lacheck.............................|ale-tex-lacheck|
    typescript............................|ale-typescript-options|
      tslint..............................|ale-typescript-tslint|
    vim...................................|ale-vim-options|
      vint................................|ale-vim-vint|
    xml...................................|ale-xml-options|
      xmllint.............................|ale-xml-xmllint|
    yaml..................................|ale-yaml-options|
      yamllint............................|ale-yaml-yamllint|
  6. Commands/Keybinds....................|ale-commands|
  7. API..................................|ale-api|
  8. Special Thanks.......................|ale-special-thanks|
  9. Contact..............................|ale-contact|

===============================================================================
1. Introduction                                              *ale-introduction*

ALE provides the means to run linters asynchronously in Vim in a variety of
languages and tools. ALE sends the contents of buffers to linter programs
using the |job-control| features available in Vim 8 and NeoVim. For Vim 8,
Vim must be compiled with the |job| and |channel| and |timer| features
as a minimum.

ALE supports the following key features for linting:

1. Running linters when text is changed.
2. Running linters when files are opened.
3. Running linters when files are saved. (When a global flag is set.)
4. Populating the |loclist| with warning and errors.
5. Setting |signs| with warnings and errors for error markers.
6. Using |echo| to show error messages when the cursor moves.
7. Setting syntax highlights for errors.

ALE can fix problems with files with the |ALEFix| command, using the same job
control functionality used for checking for problems.

===============================================================================
2. Supported Languages & Tools                                    *ale-support*

The following languages and tools are supported.

* ASM: 'gcc'
* Ansible: 'ansible-lint'
* Asciidoc: 'proselint'
* Bash: 'shell' (-n flag), 'shellcheck'
* Bourne Shell: 'shell' (-n flag), 'shellcheck'
* C: 'cppcheck', 'gcc', 'clang'
* C++ (filetype cpp): 'clang', 'clangtidy', 'cppcheck', 'cpplint', 'gcc'
* C#: 'mcs'
* Chef: 'foodcritic'
* CMake: 'cmakelint'
* CoffeeScript: 'coffee', 'coffelint'
* Crystal: 'crystal'
* CSS: 'csslint', 'stylelint'
* Cython (pyrex filetype): 'cython'
* D: 'dmd'
* Dockerfile: 'hadolint'
* Elixir: 'credo', 'dogma'
* Elm: 'elm-make'
* Erlang: 'erlc'
* Fortran: 'gcc'
* Go: 'gofmt', 'go vet', 'golint', 'go build', 'gosimple', 'staticcheck'
* Haml: 'hamllint'
* Handlebars: 'ember-template-lint'
* Haskell: 'ghc', 'ghc-mod', 'hlint', 'hdevtools'
* HTML: 'HTMLHint', 'proselint', 'tidy'
* Java: 'javac'
* JavaScript: 'eslint', 'jscs', 'jshint', 'flow', 'xo'
* JSON: 'jsonlint'
* Kotlin: 'kotlinc'
* LaTeX (tex): 'chktex', 'lacheck', 'proselint'
* Lua: 'luacheck'
* Markdown: 'mdl', 'proselint', 'vale'
* MATLAB: 'mlint'
* nim: 'nim check'
* nix: 'nix-instantiate'
* nroff: 'proselint'
* Objective-C: 'clang'
* Objective-C++: 'clang'
* OCaml: 'merlin' (see |ale-linter-integration-ocaml-merlin|)
* Perl: 'perl' (-c flag), 'perlcritic'
* PHP: 'hack', 'php' (-l flag), 'phpcs', 'phpmd'
* Pod: 'proselint'
* Pug: 'pug-lint'
* Puppet: 'puppet', 'puppet-lint'
* Python: 'flake8', 'mypy', 'pylint'
* ReasonML: 'merlin'
* reStructuredText: 'proselint'
* RPM spec: 'spec'
* Rust: 'rustc' (see |ale-integration-rust|)
* Ruby: 'reek', 'rubocop'
* SASS: 'sasslint', 'stylelint'
* SCSS: 'sasslint', 'scsslint', 'stylelint'
* Scala: 'scalac'
* Slim: 'slim-lint'
* SML: 'smlnj'
* SQL: 'sqlint'
* Swift: 'swiftlint'
* Texinfo: 'proselint'
* Text: 'proselint', 'vale'
* TypeScript: 'tslint', 'typecheck'
* Verilog: 'iverilog', 'verilator'
* Vim: 'vint'
* Vim help: 'proselint'
* XHTML: 'proselint'
* XML: 'xmllint'
* YAML: 'yamllint'

===============================================================================
3. Global Options                                                 *ale-options*

g:airline#extensions#ale#enabled             *g:airline#extensions#ale#enabled*

  Type: |Number|
  Default: `1`

  Enables or disables the |airline|'s native extension for ale, which displays
  warnings and errors in the status line, prefixed by
  |airline#extensions#ale#error_symbol| and
  |airline#extensions#ale#warning_symbol|.


g:ale_change_sign_column_color                 *g:ale_change_sign_column_color*

  Type: |Number|
  Default: `0`

  When set to `1`, this option will set different highlights for the sign
  column itself when ALE reports problems with a file. This option can be
  combined with |g:ale_sign_column_always|.

  ALE uses the following highlight groups for highlighting the sign column:

  `ALESignColumnWithErrors`    -  Links to `error` by default.
  `ALESignColumnWithoutErrors` -  Uses the value for `SignColumn` by default.


g:ale_echo_cursor                                           *g:ale_echo_cursor*

  Type: |Number|
  Default: `1`

  When this option is set to `1`, a truncated message will be echoed when a
  cursor is near a warning or error. ALE will attempt to find the warning or
  error at a column nearest to the cursor when the cursor is resting on a line
  which contains a warning or error. This option can be set to `0` to disable
  this behaviour.
  The format of the message can be customizable in |g:ale_echo_msg_format|.


g:ale_echo_msg_error_str                             *g:ale_echo_msg_error_str*

  Type: |String|
  Default: `Error`

  The string used for error severity in the echoed message.
  Note |`g:ale_echo_cursor`| should be set to 1
  Note |`g:ale_echo_msg_format`| should contain the `%severity%` handler


g:ale_echo_msg_format                                   *g:ale_echo_msg_format*

  Type: |String|
  Default: `%s`

  This variable defines the format of the echoed message. The `%s` is the
  error message itself, and it can contain the following handlers:
  - `%linter%` for linter's name
  - `%severity%` for the type of severity
  Note |`g:ale_echo_cursor`| should be setted to 1


g:ale_echo_msg_warning_str                         *g:ale_echo_msg_warning_str*

  Type: |String|
  Default: `Warning`

  The string used for warning severity in the echoed message.
  Note |`g:ale_echo_cursor`| should be set to 1
  Note |`g:ale_echo_msg_format`| should contain the `%severity%` handler


g:ale_emit_conflict_warnings                     *g:ale_emit_conflict_warnings*

  Type: |Number|
  Default: `1`

  When set to `0`, ALE will not emit any warnings on startup about conflicting
  plugins. ALE will probably not work if other linting plugins are installed.


g:ale_enabled                                                   *g:ale_enabled*
                                                                *b:ale_enabled*

  Type: |Number|
  Default: `1`

  When set to `0`, this option will completely disable ALE, such that no
  error checking will be performed, etc. ALE can be toggled on and off with
  the |ALEToggle| command, which changes this option.

  ALE can be disabled in each buffer by setting `let b:ale_enabled = 0`
  Disabling ALE based on filename patterns can be accomplished by setting
  a regular expression for |g:ale_pattern_options|. For example: >

  " Disable linting for all minified JS files.
  let g:ale_pattern_options = {'\.min.js$': {'ale_enabled': 0}}
<

  See |g:ale_pattern_options| for more information on that option.


g:ale_fixers                                                     *g:ale_fixers*
                                                                 *b:ale_fixers*

  Type: |Dictionary|
  Default: `{}`

  A mapping from filetypes to |List| values for functions for fixing errors.
  See |ale-fix| for more information.

  This variable can be overriden with variables in each buffer.


g:ale_fix_on_save                                           *g:ale_fix_on_save*

  Type: |Number|
  Default: `0`

  When set to 1, ALE will fix files when they are saved.

  If |g:ale_lint_on_save| is set to 1, files will be checked with linters
  after files are fixed, only when the buffer is open, or re-opened. Changes
  to the file will saved to the file on disk.


g:ale_history_enabled                                   *g:ale_history_enabled*

  Type: |Number|
  Default: `1`

  When set to `1`, ALE will remember the last few commands which were run
  for every buffer which is open. This information can be viewed with the
  |ALEInfo| command. The size of the buffer can be controlled with the
  |g:ale_max_buffer_history_size| option.

  This option can be disabled if storing a command history is not desired.


g:ale_history_log_output                             *g:ale_history_log_output*

  Type: |Number|
  Default: `0`

  When set to `1`, ALE will store the output of commands which have completed
  successfully in the command history, and the output will be displayed when
  using |ALEInfo|.

  |g:ale_history_enabled| must be set to `1` for this output to be stored or
  printed.

  ALE will likely consume a lot of memory if this option is on, so it should
  only be used for debugging problems with linters.


g:ale_keep_list_window_open                       *g:ale_keep_list_window_open*

  Type: |Number|
  Default: `0`

  When set to `1`, this option will keep the loclist or quickfix windows
  event after all warnings/errors have been removed for files. By default
  the loclist or quicfix windows will be closed automatically when there
  are no warnings or errors.

  See: |g:ale_open_list|


g:ale_list_window_size                                 *g:ale_list_window_size*
                                                       *b:ale_list_window_size*
  Type: |Number|
  Default: `10`

  This number configures the number of lines to set for the height of windows
  opened automatically for ALE problems. The default of `10` matches the Vim
  default height.

  See |g:ale_open_list| for information on automatically opening windows
  for quickfix or the loclist.


g:ale_lint_delay                                             *g:ale_lint_delay*

  Type: |Number|
  Default: `200`

  This variable controls the milliseconds delay after which the linters will
  be run after text is changed. This option is only meaningful with the
  |g:ale_lint_on_text_changed| variable set to `always`, `insert`, or `normal`.


g:ale_lint_on_enter                                       *g:ale_lint_on_enter*

  Type: |Number|
  Default: `1`

  When this option is set to `1`, the |BufEnter| and |BufRead| events will be
  used to apply linters when buffers are first opened. If this is not desired,
  this variable can be set to `0` in your vimrc file to disable this
  behaviour.


g:ale_lint_on_filetype_changed                 *g:ale_lint_on_filetype_changed*

  Type: |Number|
  Default: `1`

  This option will cause ALE to run whenever the filetype is changed. A short
  delay will be used before linting will be done, so the filetype can be
  changed quickly several times in a row, but resulting in only one lint
  cycle.


g:ale_lint_on_save                                         *g:ale_lint_on_save*

  Type: |Number|
  Default: `1`

  This option will make ALE run the linters whenever a file is saved when it
  it set to `1` in your vimrc file. This option can be used in combination
  with the |g:ale_lint_on_enter| and |g:ale_lint_on_text_changed| options to
  make ALE only check files after that have been saved, if that is what is
  desired.


g:ale_lint_on_text_changed                         *g:ale_lint_on_text_changed*

  Type: |String|
  Default: `always`

  By default, ALE will check files with the various supported programs when
  text is changed by using the |TextChanged| event. If this behaviour is not
  desired, then this option can be disabled by setting it to `never`. The
  |g:ale_lint_delay| variable will be used to set a |timer_start()| on a
  delay, and each change to a file will continue to call |timer_stop()| and
  |timer_start()| repeatedly until the timer ticks by, and the linters will be
  run. The checking of files will run in the background, so it should not
  inhibit editing files. This option can also be set to `insert` or `normal`
  to lint when text is changed only in insert or normal mode respectively.


g:ale_lint_on_insert_leave                         *g:ale_lint_on_insert_leave*

  Type: |Number|
  Default: `0`

  This option will make ALE run the linters whenever leaving insert mode when
  it is set to `1` in your vimrc file.


g:ale_linter_aliases                                     *g:ale_linter_aliases*
                                                         *b:ale_linter_aliases*
  Type: |Dictionary|
  Default: `{}`

  The |g:ale_linter_aliases| option can be used to set aliases from one
  filetype to another. A given filetype can be mapped to use the linters
  run for another given filetype.

  This |Dictionary| will be merged with a default dictionary containing the
  following values: >

  {
  \   'zsh': 'sh',
  \   'csh': 'sh',
  \}
<
  For example, if you wish to map a new filetype `'foobar'` to run the `'php'`
  linters, you could set the following: >

  let g:ale_linter_aliases = {'foobar': 'php'}
<
  When combined with the |g:ale_linters| option, the original filetype
  (`'foobar'`) will be used for determining which linters to run,
  not the aliased type (`'php'`). This allows an aliased type to run a
  different set of linters from the type it is being mapped to.

  Passing a list of filetypes is also supported. Say you want to lint
  javascript and css embedded in HTML (using linters that support that).
  You could alias `html` like so:

  `let g:ale_linter_aliases = {'html': ['html', 'javascript', 'css']}`

  Note that `html` itself was included as an alias. That is because aliases
  will override the original linters for the aliased filetepe.

  Linter aliases can be configured in each buffer with buffer-local variables.
  ALE will first look for aliases for filetypes in the `b:ale_linter_aliases`
  variable, then `g:ale_linter_aliases`, and then a default Dictionary.


g:ale_linters                                                   *g:ale_linters*
                                                                *b:ale_linters*
  Type: |Dictionary|
  Default: `{}`

  The |g:ale_linters| option sets a |Dictionary| mapping a filetype
  to a |List| of linter programs to be run when checking particular filetypes.
  Only the filetypes specified in the dictionary will be limited in terms
  of which linters will be run.

  This |Dictionary| will be merged with a default dictionary containing the
  following values: >

  {
  \   'csh': ['shell'],
  \   'rust': ['cargo'],
  \   'text': [],
  \   'zsh': ['shell'],
  \}
<
  This option can be used to enable only a particular set of linters for a
  file. For example, you can enable only 'eslint' for JavaScript files: >

  let g:ale_linters = {'javascript': ['eslint']}
<
  If you want to disable all linters for a particular filetype, you can pass
  an empty list of linters as the value: >

  let g:ale_linters = {'javascript': []}
<
  All linters available for a given filetype can be enabled by using the
  string `'all'`: >

  let g:ale_linters = {'c': 'all'}
<
  Linters can be configured in each buffer with buffer-local variables. ALE
  will first look for linters for filetypes in the `b:ale_linters` variable,
  then `g:ale_linters`, and then a default Dictionary.


g:ale_max_buffer_history_size                   *g:ale_max_buffer_history_size*

  Type: |Number|
  Default: `20`

  This setting controls the maximum number of commands which will be stored in
  the command history used for |ALEInfo|. Command history will be rotated in
  a FIFO manner. If set to a number <= 0, then the history will be
  continuously set to an empty |List|.

  History can be disabled completely with |g:ale_history_enabled|.


g:ale_maximum_file_size                               *g:ale_maximum_file_size*
                                                      *b:ale_maximum_file_size*
  Type: |Number|
  Default: `0`

  A maximum file size in bytes for ALE to check. If set to any positive
  number, ALE will skip checking files larger than the given size.


g:ale_open_list                                               *g:ale_open_list*

  Type: |Number|
  Default: `0`

  When set to `1`, this will cause ALE to automatically open a window for
  the loclist (|lopen|) or for the quickfix list instead if
  |g:ale_set_quickfix| is `1`. (|copen|)

  The window will be kept open until all warnings or errors are cleared,
  including those not set by ALE, unless |g:ale_keep_list_window_open| is set
  to `1`, in which case the window will be kept open until closed manually.

  The window size can be configured with |g:ale_list_window_size|.


g:ale_pattern_options                                   *g:ale_pattern_options*

  Type: |Dictionary|
  Default: `{}`

  This option maps regular expression patterns to |Dictionary| values for
  buffer variables. This option can be set to automatically configure
  different settings for different files. For example: >

  let g:ale_pattern_options = {
  \   '\.foo\.js$': {
  \       'ale_linters: {'javascript': ['eslint']},
  \   },
  \}
<
  The above example will match any filename ending in `.foo.js`, and use
  only `eslint` for checking those files by setting `b:ale_linters`.

  Filenames are matched with |match()|, and patterns depend on the |magic|
  setting, unless prefixed with the special escape sequences like `'\v'`, etc.

  The patterns can match any part of a filename. The absolute path of the
  filename will be used for matching, taken from `expand('%:p')`.


g:ale_pattern_options_enabled                   *g:ale_pattern_options_enabled*

  Type: |Number|
  Default: `!empty(g:ale_pattern_options)`

  This option can be used for turning the behaviour of setting
  |g:ale_pattern_options| on or off. By default, setting a single key
  for |g:ale_pattern_options| will turn this option on.


g:ale_set_balloons                                         *g:ale_set_balloons*

  Type: |Number|
  Default: `has('balloon_eval')`

  When this option is set to `1`, balloon messages will be displayed for
  problems. Problems nearest to the cursor on the line the cursor is over will
  be displayed.


g:ale_set_highlights                                     *g:ale_set_highlights*

  Type: |Number|
  Default: `has('syntax')`

  When this option is set to `1`, highlights will be set for problems.

  ALE will use the following highlight groups for problems:

  `ALEError`        - Items with `'type': 'E'`
  `ALEWarning`      - Items with `'type': 'W'`
  `ALEInfo`         - Items with `'type': 'I'`
  `ALEStyleError`   - Items with `'type': 'E'` and `'sub_type': 'style'`
  `ALEStyleWarning` - Items with `'type': 'W'` and `'sub_type': 'style'`


g:ale_set_loclist                                           *g:ale_set_loclist*

  Type: |Number|
  Default: `1`

  When this option is set to `1`, the |loclist| will be populated with any
  warnings and errors which are found by ALE. This feature can be used to
  implement jumping between errors through typical use of |lnext| and |lprev|.


g:ale_set_quickfix                                         *g:ale_set_quickfix*

  Type: |Number|
  Default: `0`

  When this option is set to `1`, the |quickfix| list will be populated with any
  warnings and errors which are found by ALE, instead of the |loclist|. The
  loclist will never be populated when this option is on.


g:ale_set_signs                                               *g:ale_set_signs*

  Type: |Number|
  Default: `has('signs')`

  When this option is set to `1`, the |sign| column will be populated with
  signs marking where problems appear in the file.

  ALE will use the following highlight groups for problems:

  `ALEErrorSign`        - Items with `'type': 'E'`
  `ALEWarningSign`      - Items with `'type': 'W'`
  `ALEInfoSign`         - Items with `'type': 'I'`
  `ALEStyleErrorSign`   - Items with `'type': 'E'` and `'sub_type': 'style'`
  `ALEStyleWarningSign` - Items with `'type': 'W'` and `'sub_type': 'style'`

  The markers for the highlights can be customized with the following options:

  |g:ale_sign_error|
  |g:ale_sign_warning|
  |g:ale_sign_info|
  |g:ale_sign_style_error|
  |g:ale_sign_style_warning|

  When multiple problems exist on the same line, the signs will take
  precedence in the order above, from highest to lowest.


g:ale_sign_column_always                             *g:ale_sign_column_always*

  Type: |Number|
  Default: `0`

  By default, the sign gutter will disappear when all warnings and errors have
  been fixed for a file. When this option is set to `1`, the sign column will
  remain open. This can be preferable if you don't want the text in your file
  to move around as you edit a file.


g:ale_sign_error                                             *g:ale_sign_error*

  Type: |String|
  Default: `'>>'`

  The sign for errors in the sign gutter.


g:ale_sign_info                                               *g:ale_sign_info*

  Type: |String|
  Default: `g:ale_sign_warning`

  The sign for "info" markers in the sign gutter.


g:ale_sign_style_error                                 *g:ale_sign_style_error*

  Type: |String|
  Default: `g:ale_sign_error`

  The sign for style errors in the sign gutter.


g:ale_sign_style_warning                             *g:ale_sign_style_warning*

  Type: |String|
  Default: `g:ale_sign_warning`

  The sign for style warnings in the sign gutter.


g:ale_sign_offset                                           *g:ale_sign_offset*

  Type: |Number|
  Default: `1000000`

  This variable controls offset from which numeric IDs will be generated for
  new signs. Signs cannot share the same ID values, so when two Vim plugins
  set signs at the same time, the IDs have to be configured such that they do
  not conflict with one another. If the IDs used by ALE are found to conflict
  with some other plugin, this offset value can be changed, and hopefully both
  plugins will work together. See |sign-place| for more information on how
  signs are set.


g:ale_sign_warning                                         *g:ale_sign_warning*

  Type: |String|
  Default: `'--'`

  The sign for warnings in the sign gutter.


g:ale_warn_about_trailing_whitespace     *g:ale_warn_about_trailing_whitespace*
b:ale_warn_about_trailing_whitespace     *b:ale_warn_about_trailing_whitespace*

  Type: |Number|
  Default: `1`

  When this option is set to `1`, warnings relating to trailing whitespace on
  lines will be shown in signs, the loclist, and echo messages, etc. If these
  errors are found to be too irritating while edits are being made, and you
  have configured Vim to automatically remove trailing whitespace, then you
  can disable these warnings for some linters by setting this option to `0`.

  Not all linters may respect this option. If a linter does not, please file a
  bug report, and it may be possible to add such support.

  This option may be configured on a per buffer basis.


===============================================================================
4. Fixing Problems                                                    *ale-fix*

ALE can fix problems with files with the |ALEFix| command. When |ALEFix| is
run, the variable |g:ale_fixers| will be read for getting a |List| of commands
for filetypes, split on `.`, and the functions named in |g:ale_fixers| will be
executed for fixing the errors.

The values for `g:ale_fixers` can be a list of |String|, |Funcref|, or
|lambda| values. String values must either name a function, or a short name
for a function set in the ALE fixer registry.

Each function for fixing errors must accept two arguments `(buffer, lines)`,
representing the buffer being fixed and the lines to fix. The functions must
return either `0`, for changing nothing, a |List| for new lines to set, or a
|Dictionary| for describing a command to be run in the background.

When a |Dictionary| is returned for an |ALEFix| callback, the following keys
are supported for running the commands.

  `command`             A |String| for the command to run. This key is required.

                      When `%t` is included in a command string, a temporary
                      file will be created, containing the lines from the file
                      after previous adjustment have been done.

  `read_temporary_file` When set to `1`, ALE will read the contents of the
                      temporary file created for `%t`. This option can be used
                      for commands which need to modify some file on disk in
                      order to fix files.

                                                        *ale-fix-configuration*

Synchronous functions and asynchronous jobs will be run in a sequence for
fixing files, and can be combined. For example:
>
  let g:ale_fixers = {
  \   'javascript': [
  \       'DoSomething',
  \       'eslint',
  \       {buffer, lines -> filter(lines, 'v:val !=~ ''^\s*//''')},
  \   ],
  \}

  ALEFix
<
The above example will call a function called `DoSomething` which could act
upon some lines immediately, then run `eslint` from the ALE registry, and
then call a lambda function which will remove every single line comment
from the file.

For convenience, a plug mapping is defined for |ALEFix|, so you can set up a
keybind easily for fixing files. >

  " Bind F8 to fixing problems with ALE
  nmap <F8> <Plug>(ale_fix)
<
Files can be fixed automatically with the following options, which are all off
by default.

|g:ale_fix_on_save| - Fix files when they are saved.


===============================================================================
5. Integration Documentation                                 *ale-integrations*

Linter and fixer options are documented in individual help files. See the
table of contents at |ale-contents|.

Every option for programs can be set globally, or individually for each
buffer.  For example, `b:ale_python_flake8_executable` will override any
values set for `g:ale_python_flake8_executable`.


===============================================================================
6. Commands/Keybinds                                             *ale-commands*

ALEFix                                                                 *ALEFix*

  Fix problems with the current buffer. See |ale-fix| for more information.

  A plug mapping `<Plug>(ale_fix)` is defined for this command.


ALELint                                                               *ALELint*

  Run ALE once for the current buffer. This command can be used to run ALE
  manually, instead of automatically, if desired.

  This command will also run linters where `lint_file` is set to `1`, or in
  other words linters which check the file instead of the Vim buffer.

  A plug mapping `<Plug>(ale_lint)` is defined for this command.


ALEPrevious                                                       *ALEPrevious*
ALEPreviousWrap                                               *ALEPreviousWrap*
ALENext                                                               *ALENext*
ALENextWrap                                                       *ALENextWrap*
                                                      *ale-navigation-commands*

  Move between warnings or errors in a buffer. ALE will only navigate between
  the errors or warnings it generated, even if both |g:ale_set_quickfix|
  and |g:ale_set_loclist| are set to `0`.

  `ALEPrevious` and `ALENext` will stop at the top and bottom of a file, while
  `ALEPreviousWrap` and `ALENextWrap` will wrap around the file to find
  the last or first warning or error in the file, respectively.

  The following |<Plug>| mappings are defined for the commands: >
  <Plug>(ale_previous) - ALEPrevious
  <Plug>(ale_previous_wrap) - ALEPreviousWrap
  <Plug>(ale_next) - ALENext
  <Plug>(ale_next_wrap) - ALENextWrap
<
  For example, these commands could be bound to the keys Ctrl + j
  and Ctrl + k: >

  " Map movement through errors without wrapping.
  nmap <silent> <C-k> <Plug>(ale_previous)
  nmap <silent> <C-j> <Plug>(ale_next)
  " OR map keys to use wrapping.
  nmap <silent> <C-k> <Plug>(ale_previous_wrap)
  nmap <silent> <C-j> <Plug>(ale_next_wrap)
<

ALEToggle                                                           *ALEToggle*
ALEEnable                                                           *ALEEnable*
ALEDisable                                                         *ALEDisable*

  Enable or disable ALE, including all of its autocmd events, loclist items,
  quickfix items, signs, current jobs, etc. Calling this option will change
  the |g:ale_enabled| variable.


ALEDetail                                                           *ALEDetail*

  Show the full linter message for the current line. This will only have an
  effect on lines that contain a linter message.

  A plug mapping `<Plug>(ale_detail)` is defined for this command.

===============================================================================
7. API                                                                *ale-api*

ale#Queue(delay, [linting_flag])                                  *ale#Queue()*

  Run linters for the current buffer, based on the filetype of the buffer,
  with a given `delay`. A `delay` of `0` will run the linters immediately.
  The linters will always be run in the background. Calling this function
  again from the same buffer

  An optional `linting_flag` argument can be given. If `linting_flag`
  is `'lint_file'`, then linters where the `lint_file` option is set to `1` will be
  run. Linters with `lint_file` set to `1` are not run by default.


ale#engine#CreateDirectory(buffer)               *ale#engine#CreateDirectory()*

  Create a new temporary directory with a unique name, and manage that
  directory with |ale#engine#ManageDirectory()|, so it will be removed as
  soon as possible.

  It is advised to only call this function from a callback function for
  returning a linter command to run.


ale#engine#EscapeCommandPart(command_part)     *ale#engine#EscapeCommandPart()*

  Given a |String|, return a |String| with all `%` characters replaced with
  `%%` instead. This function can be used to escape strings which are
  dynamically generated for commands before handing them over to ALE,
  so that ALE doesn't treat any strings with `%` formatting sequences
  specially.


ale#engine#GetLoclist(buffer)                         *ale#engine#GetLoclist()*

  Given a buffer number, this function will rerurn the list of warnings and
  errors reported by ALE for a given buffer in the format accepted by
  |setqflist()|.


ale#engine#ManageFile(buffer, filename)               *ale#engine#ManageFile()*

  Given a buffer number for a buffer currently running some linting tasks
  and a filename, register a filename with ALE for automatic deletion after
  linting is complete, or when Vim exits.

  If Vim exits suddenly, ALE will try its best to remove temporary files, but
  ALE cannot guarantee with absolute certainty that the files will be removed.
  It is advised to create temporary files in the operating system's managed
  temporary file directory, such as with |tempname()|.

  Directory names should not be given to this function. ALE will only delete
  files and symlinks given to this function. This is to prevent entire
  directories from being accidentally deleted, say in cases of writing
  `dir . '/' . filename` where `filename` is actually `''`, etc. ALE instead
  manages directories separetly with the |ale#engine#ManageDirectory| function.


ale#engine#ManageDirectory(buffer, directory)    *ale#engine#ManageDirectory()*

  Like |ale#engine#ManageFile()|, but directories and all of their contents
  will be deleted, akin to `rm -rf directory`, which could lead to loss of
  data if mistakes are made. This command will also delete any temporary
  filenames given to it.

  It is advised to use |ale#engine#ManageFile()| instead for deleting single
  files.


ale#fix#registry#Add(name, func, filetypes, desc)      *ale#fix#registry#Add()*

  Given a |String| `name` for a name to add to the registry, a |String| `func`
  for a function name, a |List| `filetypes` for a list of filetypes to
  set for suggestions, and a |String| `desc` for a short description of
  the fixer, register a fixer in the registry.

  The `name` can then be used for |g:ale_fixers| in place of the function
  name, and suggested for fixing files.


ale#linter#Define(filetype, linter)                       *ale#linter#Define()*

  Given a |String| for a filetype and a |Dictionary| Describing a linter
  configuration, add a linter for the given filetype. The dictionaries each
  offer the following options:

  `name`                   The name of the linter. These names will be used by
                         |g:ale_linters| option for enabling/disabling
                         particular linters.

                         This argument is required.

  `callback`               A |String| or |Funcref| for a callback function
                         accepting two arguments (buffer, lines), for a
                         buffer number the output is for, and the lines of
                         output from a linter.

                         This callback function should return a |List| of
                         |Dictionary| objects in the format accepted by
                         |setqflist()|. The |List| will be sorted by line and
                         then column order so it can be searched with a binary
                         search by in future before being passed on to the
                         |loclist|, etc.

                         This argument is required.

                         The keys for each item in the List will be handled in
                         the following manner:

                         `text` - This error message is required.
                         `lnum` - The line number is required. Any strings
                           will be automatically converted to numbers by
                           using `str2nr()`.

                           Line 0 will be moved to line 1, and lines beyond
                           the end of the file will be moved to the end.
                         `col` - The column number is optional and will
                           default to `0`. Any strings will be automatically
                           coverted to number using `str2nr()`.
                         `bufnr` - The buffer number should match the buffer
                           being checked, and this value will default to
                           the buffer being checked.
                         `vcol` - Defaults to `0`.
                         `type` - Defaults to `'E'`.
                         `nr` - Defaults to `-1`.

  `executable`             A |String| naming the executable itself which
                         will be run. This value will be used to check if the
                         program requested is installed or not.

                         Either this or the `executable_callback` argument
                         must be provided.

  `executable_callback  `  A |String| or |Funcref| for a callback function
                         accepting a buffer number. A |String| should be
                         returned for the executable to check. This can be
                         used in place of `executable` when more complicated
                         processing is needed.

  `command`                A |String| for an  executable to run asynchronously.
                         This command will be fed the lines from the buffer to
                         check, and will produce the lines of output given to
                         the `callback`.

  `command_callback`       A |String| or |Funcref| for a callback function
                         accepting a buffer number. A |String| should be
                         returned for a command to run. This can be used in
                         place of `command` when more complicated processing
                         is needed.

                         If an empty string is returned from the callback,
                         no jobs for linting will be run for that linter.
                         This can be used for skipping a linter call,
                         say if no configuration file was found.

                                                            *ale-command-chain*
  `command_chain`          A |List| of |Dictionary| items defining a series
                         of commands to be run. At least one |Dictionary|
                         should be provided. Each Dictionary must contain the
                         key `callback`, defining a |String| or |Funcref| for
                         a function returning a |String| for a command to run.

                         The callback functions for each command after the
                         first command in in the chain should accept two
                         arguments `(buffer, output)`, a buffer number and a
                         |List| of lines of output from the previous command
                         in the chain.

                         The first callback function in a chain accepts only
                         a `(buffer)` argument, as there are no previous
                         commands to run which return `output`.

                         If an empty string is returned for a command in a
                         chain, that command in the chain will be skipped,
                         and the next function in the chain will be called
                         immediately instead. If the last command in a chain
                         returns an empty string, then no linting will be
                         performed.

                         Commands in the chain will all use the
                         `output_stream` value provided in the root
                         |Dictionary|. Each command in the chain can also
                         provide an `output_stream` key to override this value.
                         See the `output_stream` description for more
                         information.

                         Commands in the chain all behave as if `read_buffer`
                         is set to `0` by default, except for the last command
                         in the chain, which uses the value set for
                         `read_buffer` in the root |Dictionary|. Each command
                         in the chain can also provide a `read_buffer` key
                         to override these values.
                         See the `read_buffer` description for more
                         information.

  `output_stream`          A |String| for the output stream the lines of output
                         should be read from for the command which is run. The
                         accepted values are `'stdout'`, `'stderr'`, and
                         `'both'`. This argument defaults to `'stdout'`. This
                         argument can be set for linter programs which output
                         their errors and warnings to the stderr stream
                         instead of stdout. The option `'both'` will read
                         from both stder and stdout at the same time.

  `read_buffer`            A |Number| (`0` or `1`) indicating whether a command
                         should read the Vim buffer as input via stdin. This
                         option is set to `1` by default, and can be disabled
                         if a command manually reads from a temporary file
                         instead, etc.

                                                                *ale-lint-file*
  `lint_file`              A |Number| (`0` or `1`) indicating whether a command
                         should read the file instead of the Vim buffer. This
                         option can be used for linters which must check the
                         file on disk, and which cannot check a Vim buffer
                         instead.

                         Linters set with this option will not be run as a
                         user types, per |g:ale_lint_on_text_changed|. Linters
                         will instead be run only when events occur against
                         the file on disk, including |g:ale_lint_on_enter|
                         and |g:ale_lint_on_save|. Linters with this option
                         set to `1` will also be run when linters are run
                         manually, per |ALELint-autocmd|.

                         When this option is set to `1`, `read_buffer` will
                         be set automatically to `0`. The two options cannot
                         be used together.

  `aliases`                A |List| of aliases for the linter name.

                         This option can be set with alternative names for
                         for selecting the linter with |g:ale_linters|. This
                         setting can make it easier to guess the linter name
                         by offering a few alternatives.

  Only one of `command`, `command_callback`, or `command_chain` should be
  specified. `command_callback` is generally recommended when a command string
  needs to be generated dynamically, or any global options are used.
  `command_chain` is recommended where any system calls need to be made to
  retrieve some kind of information before running the final command.

  If temporary files or directories are created for commands run with
  `command_callback` or `command_chain`, then these tempoary files or
  directories can be managed by ALE, for automatic deletion.
  See |ale#engine#ManageFile()| and |ale#engine#ManageDirectory| for more
  information.

                                                   *ale-command-format-strings*

  All command strings will be formatted for special character sequences.
  Any substring `%s` will be replaced with the full path to the current file
  being edited. This format option can be used to pass the exact filename
  being edited to a program.

  For example: >
  'command': 'eslint -f unix --stdin --stdin-filename %s'
<
  Any substring `%t` will be replaced with a path to a temporary file. Merely
  adding `%t` will cause ALE to create a temporary file containing the
  contents of the buffer being checked. All occurrences of `%t` in command
  strings will reference the one temporary file. The temporary file will be
  created inside a temporary directory, and the entire temporary directory
  will be automatically deleted, following the behaviour of
  |ale#engine#ManageDirectory|. This option can be used for some linters which
  do not support reading from stdin.

  For example: >
  'command': 'ghc -fno-code -v0 %t',
<
  The character sequence `%%` can be used to emit a literal `%` into a
  command, so literal character sequences `%s` and `%t` can be escaped by
  using `%%s` and `%%t` instead, etc.

  If a callback for a command generates part of a command string which might
  possibly contain `%%`, `%s`, or `%t` where the special formatting behaviour
  is not desired, the |ale#engine#EscapeCommandPart()| function can be used to
  replace those characters to avoid formatting issues.

                                                 *ale-linter-loading-behaviour*

  Linters for ALE will be loaded by searching |runtimepath| in the following
  format: >

  ale_linters/<filetype>/<linter_name>.vim
<
  Any linters which exist anywhere in |runtimepath| with that directory
  structure will be automatically loaded for the matching |filetype|. Filetypes
  containing `.` characters will be split into individual parts, and files
  will be loaded for each filetype between the `.` characters.


ale#linter#Get(filetype)                                     *ale#linter#Get()*

  Return all of linters configured for a given filetype as a |List| of
  |Dictionary| values in the format specified by |ale#linter#Define()|.

  Filetypes may be dot-seperated to invoke linters for multiple filetypes:
  for instance, the filetype `javascript.jsx` will return linters for both the
  `javascript` and `jsx` filetype.

  Aliases may be defined in as described in |g:ale_linter_aliases|. Aliases
  are applied after dot-seperated filetypes are broken up into their
  components.


ale#statusline#Count(buffer)                           *ale#statusline#Count()*

  Given the number of a buffer which may have problems, return a |Dictionary|
  containing information about the number of problems detected by ALE. The
  following keys are supported:

  `error`         -> The number of problems with type `E` and `sub_type != 'style'`
  `warning`       -> The number of problems with type `W` and `sub_type != 'style'`
  `info`          -> The number of problems with type `I`
  `style_error`   -> The number of problems with type `E` and `sub_type == 'style'`
  `style_warning` -> The number of problems with type `W` and `sub_type == 'style'`
  `total`         -> The total number of problems.


ALELint                                                       *ALELint-autocmd*

  This |User| autocommand is triggered by ALE every time it completes a lint
  cycle. It can be used to update statuslines, send notifications, or
  complete any other operation that needs to be done after linting has been
  performed.

  For example, you can echo a message when linting is complete like so:
  >
  autocmd User ALELint echom "ALE run!"
<

===============================================================================
8. Special Thanks                                          *ale-special-thanks*

Special thanks to Mark Grealish (https://www.bhalash.com/) for providing ALE's
snazzy looking ale glass logo. Cheers, Mark!

===============================================================================
9. Contact                                                        *ale-contact*

If you like this plugin, and wish to get in touch, check out the GitHub
page for issues and more at https://github.com/w0rp/ale

If you wish to contact the author of this plugin directly, please feel
free to send an email to devw0rp@gmail.com.


Please drink responsibly, or not at all, which is ironically the preference
of w0rp, who is teetotal.



  vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl: