feat(lua)!: execute Lua with "nvim -l"

Problem:
Nvim has Lua but the "nvim" CLI can't easily be used to execute Lua
scripts, especially scripts that take arguments or produce output.

Solution:
- support "nvim -l [args...]" for running scripts. closes #15749
- exit without +q
- remove lua2dox_filter
- remove Doxyfile. This wasn't used anyway, because the doxygen config
  is inlined in gen_vimdoc.py (`Doxyfile` variable).
- use "nvim -l" in docs-gen CI job

Examples:

    $ nvim -l scripts/lua2dox.lua --help
    Lua2DoX (0.2 20130128)
    ...

    $ echo "print(vim.inspect(_G.arg))" | nvim -l - --arg1 --arg2
    $ echo 'print(vim.inspect(vim.api.nvim_buf_get_text(1,0,0,-1,-1,{})))' | nvim +"put ='text'" -l -

TODO?
  -e executes Lua code
  -l loads a module
  -i enters REPL _after running the other arguments_.

16 files changed, 311 insertions, 2784 deletions

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2af9bc49d8..6e727448b9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -205,6 +205,8 @@ jobs:
     env:
       CC: ${{ matrix.cc }}
       CI_OS_NAME: ${{ matrix.os }}
+      # TEST_FILE: test/functional/core/startup_spec.lua
+      # TEST_FILTER: foo
     steps:
       - uses: actions/checkout@v3
 
@@ -281,6 +283,8 @@ jobs:
       DEPS_BUILD_DIR: ${{ github.workspace }}/nvim-deps
       CACHE_NVIM_DEPS_DIR: ${{ github.workspace }}/nvim-deps
       DEPS_PREFIX: ${{ github.workspace }}/nvim-deps/usr
+      # TEST_FILE: test/functional/core/startup_spec.lua
+      # TEST_FILTER: foo
     name: windows (MSVC_64)
     steps:
       - uses: actions/checkout@v3
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 1942ff51f7..d0af90d679 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -116,10 +116,7 @@ Each pull request must pass the automated builds on [Cirrus CI] and [GitHub Acti
 
 - CI builds are compiled with [`-Werror`][gcc-warnings], so compiler warnings
   will fail the build.
-- If any tests fail, the build will fail.
-  See [test/README.md#running-tests][run-tests] to run tests locally.
-  Passing locally doesn't guarantee passing the CI build, because of the
-  different compilers and platforms tested against.
+- If any tests fail, the build will fail. See [test/README.md#running-tests][run-tests] to run tests locally.
 - CI runs [ASan] and other analyzers.
     - To run valgrind locally: `VALGRIND=1 make test`
     - To run Clang ASan/UBSan locally: `CC=clang make CMAKE_FLAGS="-DCLANG_ASAN_UBSAN=ON"`
@@ -127,6 +124,8 @@ Each pull request must pass the automated builds on [Cirrus CI] and [GitHub Acti
   neighbors_, to encourage incrementally updating the legacy style to meet our
   [style](#style). (See [#3174][3174] for background.)
 - CI for FreeBSD runs on [Cirrus CI].
+- To see CI results faster in your PR, you can temporarily set `TEST_FILE` in
+  [ci.yml](https://github.com/neovim/neovim/blob/e35b9020b16985eee26e942f9a3f6b045bc3809b/.github/workflows/ci.yml#L205).
 
 ### Clang scan-build
 
diff --git a/runtime/doc/lua.txt b/runtime/doc/lua.txt
index 9cb189b927..16d0bcb612 100644
--- a/runtime/doc/lua.txt
+++ b/runtime/doc/lua.txt
@@ -21,15 +21,19 @@ Nvim includes a "standard library" |lua-stdlib| for Lua.  It complements the
 which can be used from Lua code (|lua-vimscript| |vim.api|). Together these
 "namespaces" form the Nvim programming interface.
 
-See the |lua-guide| for an introduction to using Lua in Neovim.
+Lua plugins and user config are automatically discovered and loaded, just like
+Vimscript. See |lua-guide| for practical guidance.
 
+You can also run Lua scripts from your shell using the |-l| argument: >
+    nvim -l foo.lua [args...]
+<
                                                                   *lua-compat*
 Lua 5.1 is the permanent interface for Nvim Lua.  Plugins need only consider
 Lua 5.1, not worry about forward-compatibility with future Lua versions.  If
 Nvim ever ships with Lua 5.4+, a Lua 5.1 compatibility shim will be provided
 so that old plugins continue to work transparently.
 
-------------------------------------------------------------------------------
+==============================================================================
 LUA CONCEPTS AND IDIOMS                                         *lua-concepts*
 
 Lua is very simple: this means that, while there are some quirks, once you
@@ -73,25 +77,24 @@ In Lua, any missing arguments are passed as `nil`. Example: >lua
 Furthermore it is not an error if extra parameters are passed, they are just
 discarded.
 
-It is also allowed to omit the parentheses (only) if the function takes
-exactly one string (`"foo"`) or table literal (`{1,2,3}`). The latter is often
-used to approximate the "named parameters" feature of languages like Python
-("kwargs" or "keyword args"). Example: >lua
+                                                                      *kwargs*
+When calling a function, you can omit the parentheses if the function takes
+exactly one string literal (`"foo"`) or table literal (`{1,2,3}`). The latter
+is often used to approximate "named parameters" ("kwargs" or "keyword args")
+as in languages like Python and C#. Example: >lua
     local func_with_opts = function(opts)
         local will_do_foo = opts.foo
         local filename = opts.filename
-
         ...
     end
 
     func_with_opts { foo = true, filename = "hello.world" }
 <
-There is nothing special going on here except that parentheses are treated as
+There's nothing special going on here except that parentheses are treated as
 whitespace. But visually, this small bit of sugar gets reasonably close to
 a "keyword args" interface.
 
 It is of course also valid to call the function with parentheses: >lua
-
     func_with_opts({ foo = true, filename = "hello.world" })
 <
 Nvim tends to prefer the keyword args style.
@@ -100,25 +103,20 @@ Nvim tends to prefer the keyword args style.
 LUA PATTERNS                                                    *lua-patterns*
 
 Lua intentionally does not support regular expressions, instead it has limited
-"patterns" which avoid the performance pitfalls of extended regex.
-|luaref-patterns|
+"patterns" |luaref-patterns| which avoid the performance pitfalls of extended
+regex. Lua scripts can also use Vim regex via |vim.regex()|.
 
-Examples using |string.match()|: >lua
+These examples use |string.match()| to demonstrate Lua patterns: >lua
 
     print(string.match("foo123bar123", "%d+"))
     -- 123
-
     print(string.match("foo123bar123", "[^%d]+"))
     -- foo
-
     print(string.match("foo123bar123", "[abc]+"))
     -- ba
-
     print(string.match("foo.bar", "%.bar"))
     -- .bar
 
-For more complex matching you can use Vim regex from Lua via |vim.regex()|.
-
 ==============================================================================
 IMPORTING LUA MODULES                                  *require()* *lua-require*
 
@@ -389,7 +387,7 @@ For example consider the following Lua omnifunc handler: >lua
     vim.api.nvim_buf_set_option(0, 'omnifunc', 'v:lua.mymod.omnifunc')
 
 Note: The module ("mymod" in the above example) must either be a Lua global,
-or use the require syntax as specified above to access it from a package.
+or use require() as shown above to access it from a package.
 
 Note: `v:lua` without a call is not allowed in a Vimscript expression:
 |Funcref|s cannot represent Lua functions. The following are errors: >vim
diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index a764b2b882..3e291e59c9 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -57,6 +57,11 @@ The following new APIs or features were added.
 <
   (or the Vimscript equivalent) to their |config| file.
 
+• Run Lua scripts from your shell using |-l|. >
+      nvim -l foo.lua --arg1 --arg2
+<  Also works with stdin: >
+      echo "print(42)" | nvim -l -
+
 • Added a |vim.lsp.codelens.clear()| function to clear codelenses.
 
 • |vim.inspect_pos()|, |vim.show_pos()| and |:Inspect| allow a user to get or show items
diff --git a/runtime/doc/starting.txt b/runtime/doc/starting.txt
index 8b662ab1bf..a99be4ab93 100644
--- a/runtime/doc/starting.txt
+++ b/runtime/doc/starting.txt
@@ -9,7 +9,7 @@ Starting Vim						*starting*
                                       Type |gO| to see the table of contents.
 
 ==============================================================================
-Nvim arguments						*vim-arguments*
+Nvim arguments						*cli-arguments*
 
 Most often, Nvim is started to edit a single file with the command: >
 
@@ -31,8 +31,8 @@ filename	One or more file names.  The first one will be the current
 		To avoid a file name starting with a '-' being interpreted as
 		an option, precede the arglist with "--", e.g.: >
 			nvim -- -filename
-<		All arguments after the "--" will be interpreted as file names,
-		no other options or "+command" argument can follow.
+<		All arguments after "--" are interpreted as file names, no
+		other options or "+command" argument can follow.
 
 							*--*
 `-`		Alias for stdin (standard input).
@@ -143,15 +143,13 @@ argument.
 		these commands, independently from "-c" commands.
 
 							*-S*
--S {file}	Vimscript or Lua (".lua") {file} will be |:source|d after the
-		first file has been read. Equivalent to: >
+-S [file]	Vimscript or Lua (".lua") [file] will be |:source|d after the
+		first file has been read or "Session.vim" if [file] is not
+		given. Equivalent to: >
 			-c "source {file}"
 <		Can be repeated like "-c", subject to the same limit of 10
 		"-c" arguments. {file} cannot start with a "-".
 
--S		Works like "-S Session.vim".  Only when used as the last
-		argument or when another "-" option follows.
-
 -L							*-L* *-r*
 -r		Recovery mode.  Without a file name argument, a list of
 		existing swap files is given.  With a file name, a swap file
@@ -211,10 +209,30 @@ argument.
 			nvim -es +":verbose echo 'foo'"
 			nvim -V1 -es +foo
 
-<		User |config| is skipped (unless given with |-u|).
+<		User |config| is skipped unless |-u| was given.
 		Swap file is skipped (like |-n|).
 		User |shada| is loaded (unless "-i NONE" is given).
 
+							*-l*
+-l {script} [args]
+		Executes Lua {script} file and exits. All [args] (up to "--"
+		|---|) are treated as {script} args, not Nvim args: by Lua
+		convention they are set in the `_G.arg` global table.  *lua-args*
+		On {script} error, Nvim exits with code 1.
+
+		Sets 'verbose' to 1 (like "-V1"), so Lua `print()` writes to
+		output.
+
+		Any |cli-arguments| before "-l" are processed before executing
+		{script}. For example this quits before executing "foo.lua": >
+			nvim +q -l foo.lua
+<		This loads Lua module "bar" before executing "foo.lua": >
+			nvim +"lua require('bar')" -l foo.lua
+<
+		User |config| is skipped unless |-u| was given.
+		User |shada| is skipped unless |-i| was given.
+		Swap file is skipped (like |-n|).
+
 							*-b*
 -b		Binary mode.  File I/O will only recognize <NL> to separate
 		lines.  The 'expandtab' option will be reset.  The 'textwidth'
@@ -222,9 +240,6 @@ argument.
 		is set.  This is done after reading the |vimrc| but before
 		reading any file in the arglist.  See also |edit-binary|.
 
-							*-l*
--l		Lisp mode.  Sets the 'lisp' and 'showmatch' options on.
-
 							*-A*
 -A		Arabic mode.  Sets the 'arabic' option on.
 
@@ -239,10 +254,10 @@ argument.
 		Example: >
 			nvim -V8
 
--V[N]{filename}
-		Like -V and set 'verbosefile' to {filename}.  Messages are not
-		displayed; instead they are written to the file {filename}.
-		{filename} must not start with a digit.
+-V[N]{file}
+		Like -V and sets 'verbosefile' to {file} (must not start with
+		a digit).  Messages are not displayed; instead they are
+		written to {file}.
 		Example: >
 			nvim -V20vimlog
 <
diff --git a/scripts/gen_vimdoc.py b/scripts/gen_vimdoc.py
index 502c9161b6..8e1d6ef80a 100755
--- a/scripts/gen_vimdoc.py
+++ b/scripts/gen_vimdoc.py
@@ -55,11 +55,19 @@ if sys.version_info < MIN_PYTHON_VERSION:
 doxygen_version = tuple((int(i) for i in subprocess.check_output(["doxygen", "-v"],
                         universal_newlines=True).split()[0].split('.')))
 
+# Until 0.9 is released, need this hacky way to check that "nvim -l foo.lua" works.
+nvim_version = list(line for line in subprocess.check_output(['nvim', '-h'], universal_newlines=True).split('\n')
+                     if '-l ' in line)
+
 if doxygen_version < MIN_DOXYGEN_VERSION:
     print("\nRequires doxygen {}.{}.{}+".format(*MIN_DOXYGEN_VERSION))
     print("Your doxygen version is {}.{}.{}\n".format(*doxygen_version))
     sys.exit(1)
 
+if len(nvim_version) == 0:
+    print("\nRequires 'nvim -l' feature, see https://github.com/neovim/neovim/pull/18706")
+    sys.exit(1)
+
 # DEBUG = ('DEBUG' in os.environ)
 INCLUDE_C_DECL = ('INCLUDE_C_DECL' in os.environ)
 INCLUDE_DEPRECATED = ('INCLUDE_DEPRECATED' in os.environ)
@@ -79,7 +87,7 @@ base_dir = os.path.dirname(os.path.dirname(script_path))
 out_dir = os.path.join(base_dir, 'tmp-{target}-doc')
 filter_cmd = '%s %s' % (sys.executable, script_path)
 msgs = []  # Messages to show on exit.
-lua2dox_filter = os.path.join(base_dir, 'scripts', 'lua2dox_filter')
+lua2dox = os.path.join(base_dir, 'scripts', 'lua2dox.lua')
 
 CONFIG = {
     'api': {
@@ -993,7 +1001,7 @@ def delete_lines_below(filename, tokenstr):
         fp.writelines(lines[0:i])
 
 
-def main(config, args):
+def main(doxygen_config, args):
     """Generates:
 
     1. Vim :help docs
@@ -1021,7 +1029,7 @@ def main(config, args):
                 # runtime/lua/vim/lsp.lua:209: warning: argument 'foo' not found
                 stderr=(subprocess.STDOUT if debug else subprocess.DEVNULL))
         p.communicate(
-            config.format(
+            doxygen_config.format(
                 input=' '.join(
                     [f'"{file}"' for file in CONFIG[target]['files']]),
                 output=output_dir,
@@ -1108,11 +1116,7 @@ def main(config, args):
                         fn_map_full.update(fn_map)
 
         if len(sections) == 0:
-            if target == 'lua':
-                fail(f'no sections for target: {target} (this usually means'
-                     + ' "luajit" was not found by scripts/lua2dox_filter)')
-            else:
-                fail(f'no sections for target: {target}')
+            fail(f'no sections for target: {target} (look for errors near "Preprocessing" log lines above)')
         if len(sections) > len(CONFIG[target]['section_order']):
             raise RuntimeError(
                 'found new modules "{}"; update the "section_order" map'.format(
@@ -1159,7 +1163,7 @@ def main(config, args):
 def filter_source(filename):
     name, extension = os.path.splitext(filename)
     if extension == '.lua':
-        p = subprocess.run([lua2dox_filter, filename], stdout=subprocess.PIPE)
+        p = subprocess.run(['nvim', '-l', lua2dox, filename], stdout=subprocess.PIPE)
         op = ('?' if 0 != p.returncode else p.stdout.decode('utf-8'))
         print(op)
     else:
diff --git a/scripts/lua2dox.lua b/scripts/lua2dox.lua
index 83bf213f40..19f8f8141d 100644
--- a/scripts/lua2dox.lua
+++ b/scripts/lua2dox.lua
@@ -27,14 +27,13 @@ http://search.cpan.org/~alec/Doxygen-Lua-0.02/lib/Doxygen/Lua.pm
 Running
 -------
 
-This file "lua2dox.lua" gets called by "lua2dox_filter" (bash).
+This script "lua2dox.lua" gets called by "gen_vimdoc.py".
 
 Doxygen must be on your system. You can experiment like so:
 
 - Run "doxygen -g" to create a default Doxyfile.
-- Then alter it to let it recognise lua. Add the two following lines:
+- Then alter it to let it recognise lua. Add the following line:
     FILE_PATTERNS   = *.lua
-    FILTER_PATTERNS = *.lua=lua2dox_filter
 - Then run "doxygen".
 
 The core function reads the input file (filename or stdin) and outputs some pseudo C-ish language.
@@ -117,26 +116,6 @@ local function string_split(Str, Pattern)
   return splitStr
 end
 
---! \class TCore_Commandline
---! \brief reads/parses commandline
-local TCore_Commandline = class()
-
---! \brief constructor
-function TCore_Commandline.init(this)
-  this.argv = arg
-  this.parsed = {}
-  this.params = {}
-end
-
---! \brief get value
-function TCore_Commandline.getRaw(this, Key, Default)
-  local val = this.argv[Key]
-  if not val then
-    val = Default
-  end
-  return val
-end
-
 -------------------------------
 --! \brief file buffer
 --!
@@ -147,7 +126,7 @@ local TStream_Read = class()
 --!
 --! \param Filename name of file to read (or nil == stdin)
 function TStream_Read.getContents(this, Filename)
-  assert(Filename)
+  assert(Filename, ('invalid file: %s'):format(Filename))
   -- get lines from file
   -- syphon lines to our table
   local filecontents = {}
@@ -548,15 +527,14 @@ end
 local This_app = TApp()
 
 --main
-local cl = TCore_Commandline()
 
-local argv1 = cl:getRaw(2)
+local argv1 = arg[1]
 if argv1 == '--help' then
   TCore_IO_writeln(This_app:getVersion())
   TCore_IO_writeln(This_app:getCopyright())
   TCore_IO_writeln([[
   run as:
-  lua2dox_filter <param>
+  nvim -l scripts/lua2dox.lua <param>
   --------------
   Param:
   <filename> : interprets filename
diff --git a/scripts/lua2dox_filter b/scripts/lua2dox_filter
deleted file mode 100755
index e3fa95d0cf..0000000000
--- a/scripts/lua2dox_filter
+++ /dev/null
@@ -1,90 +0,0 @@
-#!/usr/bin/env bash
-
-###########################################################################
-#   Copyright (C) 2012 by Simon Dales   #
-#   simon@purrsoft.co.uk   #
-#                                                                         #
-#   This program is free software; you can redistribute it and/or modify  #
-#   it under the terms of the GNU General Public License as published by  #
-#   the Free Software Foundation; either version 2 of the License, or     #
-#   (at your option) any later version.                                   #
-#                                                                         #
-#   This program is distributed in the hope that it will be useful,       #
-#   but WITHOUT ANY WARRANTY; without even the implied warranty of        #
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         #
-#   GNU General Public License for more details.                          #
-#                                                                         #
-#   You should have received a copy of the GNU General Public License     #
-#   along with this program; if not, write to the                         #
-#   Free Software Foundation, Inc.,                                       #
-#   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             #
-###########################################################################
-LANG=""
-
-##! \brief test executable to see if it exists
-test_executable() {
-  P_EXE="$1"
-  #########
-  WHICH=$(which "$P_EXE")
-  if test -z "${WHICH}"; then
-    echo "not found \"${P_EXE}\""
-  else
-    EXE="${P_EXE}"
-  fi
-}
-
-##! \brief sets the lua interpreter
-set_lua() {
-  if test -z "${EXE}"; then
-    test_executable '.deps/usr/bin/luajit'
-  fi
-
-  if test -z "${EXE}"; then
-    test_executable 'luajit'
-  fi
-
-  if test -z "${EXE}"; then
-    test_executable 'lua'
-  fi
-}
-
-##! \brief makes canonical name of file
-##!
-##! Note that "readlink -f" doesn't work in MacOSX
-##!
-do_readlink() {
-  pushd . > /dev/null
-  TARGET_FILE=$1
-
-  cd "$(dirname $TARGET_FILE)"
-  TARGET_FILE=$(basename "$TARGET_FILE")
-
-  # Iterate down a (possible) chain of symlinks
-  while [ -L "$TARGET_FILE" ]; do
-    TARGET_FILE=$(readlink "$TARGET_FILE")
-    cd $(dirname "$TARGET_FILE")
-    TARGET_FILE=$(basename "$TARGET_FILE")
-  done
-
-  PHYS_DIR=$(pwd -P)
-  RESULT=$PHYS_DIR
-  popd > /dev/null
-}
-
-##main
-set_lua
-if test -z "${EXE}"; then
-  echo "no lua interpreter found"
-  exit 1
-else
-  BASENAME=$(basename "$0")
-  do_readlink "$0"
-  DIRNAME="${RESULT}"
-
-  LUASCRIPT="${DIRNAME}/lua2dox.lua ${BASENAME}"
-  #echo "lua[${LUASCRIPT}]"
-
-  ${EXE} ${LUASCRIPT} $@
-fi
-
-##eof
diff --git a/src/Doxyfile b/src/Doxyfile
deleted file mode 100644
index e085e4e198..0000000000
--- a/src/Doxyfile
+++ /dev/null
@@ -1,2566 +0,0 @@
-# Doxyfile 1.9.0
-
-# This file describes the settings to be used by the documentation system
-# doxygen (www.doxygen.org) for a project.
-#
-# All text after a double hash (##) is considered a comment and is placed in
-# front of the TAG it is preceding.
-#
-# All text after a single hash (#) is considered a comment and will be ignored.
-# The format is:
-# TAG = value [value, ...]
-# For lists, items can also be appended using:
-# TAG += value [value, ...]
-# Values that contain spaces should be placed between quotes (\" \").
-
-#---------------------------------------------------------------------------
-# Project related configuration options
-#---------------------------------------------------------------------------
-
-# This tag specifies the encoding used for all characters in the configuration
-# file that follow. The default is UTF-8 which is also the encoding used for all
-# text before the first occurrence of this tag. Doxygen uses libiconv (or the
-# iconv built into libc) for the transcoding. See
-# https://www.gnu.org/software/libiconv/ for the list of possible encodings.
-# The default value is: UTF-8.
-
-DOXYFILE_ENCODING      = UTF-8
-
-# The PROJECT_NAME tag is a single word (or a sequence of words surrounded by
-# double-quotes, unless you are using Doxywizard) that should identify the
-# project for which the documentation is generated. This name is used in the
-# title of most generated pages and in a few other places.
-# The default value is: My Project.
-
-PROJECT_NAME           = Neovim
-
-# The PROJECT_NUMBER tag can be used to enter a project or revision number. This
-# could be handy for archiving the generated documentation or if some version
-# control system is used.
-
-PROJECT_NUMBER         =
-
-# Using the PROJECT_BRIEF tag one can provide an optional one line description
-# for a project that appears at the top of each page and should give viewer a
-# quick idea about the purpose of the project. Keep the description short.
-
-PROJECT_BRIEF          =
-
-# With the PROJECT_LOGO tag one can specify a logo or an icon that is included
-# in the documentation. The maximum height of the logo should not exceed 55
-# pixels and the maximum width should not exceed 200 pixels. Doxygen will copy
-# the logo to the output directory.
-
-PROJECT_LOGO           = contrib/doxygen/logo-devdoc.png
-
-# The OUTPUT_DIRECTORY tag is used to specify the (relative or absolute) path
-# into which the generated documentation will be written. If a relative path is
-# entered, it will be relative to the location where doxygen was started. If
-# left blank the current directory will be used.
-
-OUTPUT_DIRECTORY       = build/doxygen
-
-# If the CREATE_SUBDIRS tag is set to YES then doxygen will create 4096 sub-
-# directories (in 2 levels) under the output directory of each output format and
-# will distribute the generated files over these directories. Enabling this
-# option can be useful when feeding doxygen a huge amount of source files, where
-# putting all generated files in the same directory would otherwise causes
-# performance problems for the file system.
-# The default value is: NO.
-
-CREATE_SUBDIRS         = NO
-
-# If the ALLOW_UNICODE_NAMES tag is set to YES, doxygen will allow non-ASCII
-# characters to appear in the names of generated files. If set to NO, non-ASCII
-# characters will be escaped, for example _xE3_x81_x84 will be used for Unicode
-# U+3044.
-# The default value is: NO.
-
-ALLOW_UNICODE_NAMES    = NO
-
-# The OUTPUT_LANGUAGE tag is used to specify the language in which all
-# documentation generated by doxygen is written. Doxygen will use this
-# information to generate all constant output in the proper language.
-# Possible values are: Afrikaans, Arabic, Armenian, Brazilian, Catalan, Chinese,
-# Chinese-Traditional, Croatian, Czech, Danish, Dutch, English (United States),
-# Esperanto, Farsi (Persian), Finnish, French, German, Greek, Hungarian,
-# Indonesian, Italian, Japanese, Japanese-en (Japanese with English messages),
-# Korean, Korean-en (Korean with English messages), Latvian, Lithuanian,
-# Macedonian, Norwegian, Persian (Farsi), Polish, Portuguese, Romanian, Russian,
-# Serbian, Serbian-Cyrillic, Slovak, Slovene, Spanish, Swedish, Turkish,
-# Ukrainian and Vietnamese.
-# The default value is: English.
-
-OUTPUT_LANGUAGE        = English
-
-# The OUTPUT_TEXT_DIRECTION tag is used to specify the direction in which all
-# documentation generated by doxygen is written. Doxygen will use this
-# information to generate all generated output in the proper direction.
-# Possible values are: None, LTR, RTL and Context.
-# The default value is: None.
-
-OUTPUT_TEXT_DIRECTION  = None
-
-# If the BRIEF_MEMBER_DESC tag is set to YES, doxygen will include brief member
-# descriptions after the members that are listed in the file and class
-# documentation (similar to Javadoc). Set to NO to disable this.
-# The default value is: YES.
-
-BRIEF_MEMBER_DESC      = YES
-
-# If the REPEAT_BRIEF tag is set to YES, doxygen will prepend the brief
-# description of a member or function before the detailed description
-#
-# Note: If both HIDE_UNDOC_MEMBERS and BRIEF_MEMBER_DESC are set to NO, the
-# brief descriptions will be completely suppressed.
-# The default value is: YES.
-
-REPEAT_BRIEF           = YES
-
-# This tag implements a quasi-intelligent brief description abbreviator that is
-# used to form the text in various listings. Each string in this list, if found
-# as the leading text of the brief description, will be stripped from the text
-# and the result, after processing the whole list, is used as the annotated
-# text. Otherwise, the brief description is used as-is. If left blank, the
-# following values are used ($name is automatically replaced with the name of
-# the entity):The $name class, The $name widget, The $name file, is, provides,
-# specifies, contains, represents, a, an and the.
-
-ABBREVIATE_BRIEF       =
-
-# If the ALWAYS_DETAILED_SEC and REPEAT_BRIEF tags are both set to YES then
-# doxygen will generate a detailed section even if there is only a brief
-# description.
-# The default value is: NO.
-
-ALWAYS_DETAILED_SEC    = NO
-
-# If the INLINE_INHERITED_MEMB tag is set to YES, doxygen will show all
-# inherited members of a class in the documentation of that class as if those
-# members were ordinary class members. Constructors, destructors and assignment
-# operators of the base classes will not be shown.
-# The default value is: NO.
-
-INLINE_INHERITED_MEMB  = NO
-
-# If the FULL_PATH_NAMES tag is set to YES, doxygen will prepend the full path
-# before files name in the file list and in the header files. If set to NO the
-# shortest path that makes the file name unique will be used
-# The default value is: YES.
-
-FULL_PATH_NAMES        = YES
-
-# The STRIP_FROM_PATH tag can be used to strip a user-defined part of the path.
-# Stripping is only done if one of the specified strings matches the left-hand
-# part of the path. The tag can be used to show relative paths in the file list.
-# If left blank the directory from which doxygen is run is used as the path to
-# strip.
-#
-# Note that you can specify absolute paths here, but also relative paths, which
-# will be relative from the directory where doxygen is started.
-# This tag requires that the tag FULL_PATH_NAMES is set to YES.
-
-STRIP_FROM_PATH        =
-
-# The STRIP_FROM_INC_PATH tag can be used to strip a user-defined part of the
-# path mentioned in the documentation of a class, which tells the reader which
-# header file to include in order to use a class. If left blank only the name of
-# the header file containing the class definition is used. Otherwise one should
-# specify the list of include paths that are normally passed to the compiler
-# using the -I flag.
-
-STRIP_FROM_INC_PATH    =
-
-# If the SHORT_NAMES tag is set to YES, doxygen will generate much shorter (but
-# less readable) file names. This can be useful is your file systems doesn't
-# support long names like on DOS, Mac, or CD-ROM.
-# The default value is: NO.
-
-SHORT_NAMES            = NO
-
-# If the JAVADOC_AUTOBRIEF tag is set to YES then doxygen will interpret the
-# first line (until the first dot) of a Javadoc-style comment as the brief
-# description. If set to NO, the Javadoc-style will behave just like regular Qt-
-# style comments (thus requiring an explicit @brief command for a brief
-# description.)
-# The default value is: NO.
-
-JAVADOC_AUTOBRIEF      = NO
-
-# If the JAVADOC_BANNER tag is set to YES then doxygen will interpret a line
-# such as
-# /***************
-# as being the beginning of a Javadoc-style comment "banner". If set to NO, the
-# Javadoc-style will behave just like regular comments and it will not be
-# interpreted by doxygen.
-# The default value is: NO.
-
-JAVADOC_BANNER         = NO
-
-# If the QT_AUTOBRIEF tag is set to YES then doxygen will interpret the first
-# line (until the first dot) of a Qt-style comment as the brief description. If
-# set to NO, the Qt-style will behave just like regular Qt-style comments (thus
-# requiring an explicit \brief command for a brief description.)
-# The default value is: NO.
-
-QT_AUTOBRIEF           = NO
-
-# The MULTILINE_CPP_IS_BRIEF tag can be set to YES to make doxygen treat a
-# multi-line C++ special comment block (i.e. a block of //! or /// comments) as
-# a brief description. This used to be the default behavior. The new default is
-# to treat a multi-line C++ comment block as a detailed description. Set this
-# tag to YES if you prefer the old behavior instead.
-#
-# Note that setting this tag to YES also means that rational rose comments are
-# not recognized any more.
-# The default value is: NO.
-
-MULTILINE_CPP_IS_BRIEF = NO
-
-# By default Python docstrings are displayed as preformatted text and doxygen's
-# special commands cannot be used. By setting PYTHON_DOCSTRING to NO the
-# doxygen's special commands can be used and the contents of the docstring
-# documentation blocks is shown as doxygen documentation.
-# The default value is: YES.
-
-PYTHON_DOCSTRING       = YES
-
-# If the INHERIT_DOCS tag is set to YES then an undocumented member inherits the
-# documentation from any documented member that it re-implements.
-# The default value is: YES.
-
-INHERIT_DOCS           = YES
-
-# If the SEPARATE_MEMBER_PAGES tag is set to YES then doxygen will produce a new
-# page for each member. If set to NO, the documentation of a member will be part
-# of the file/class/namespace that contains it.
-# The default value is: NO.
-
-SEPARATE_MEMBER_PAGES  = NO
-
-# The TAB_SIZE tag can be used to set the number of spaces in a tab. Doxygen
-# uses this value to replace tabs by spaces in code fragments.
-# Minimum value: 1, maximum value: 16, default value: 4.
-
-TAB_SIZE               = 4
-
-# This tag can be used to specify a number of aliases that act as commands in
-# the documentation. An alias has the form:
-# name=value
-# For example adding
-# "sideeffect=@par Side Effects:\n"
-# will allow you to put the command \sideeffect (or @sideeffect) in the
-# documentation, which will result in a user-defined paragraph with heading
-# "Side Effects:". You can put \n's in the value part of an alias to insert
-# newlines (in the resulting output). You can put ^^ in the value part of an
-# alias to insert a newline as if a physical newline was in the original file.
-# When you need a literal { or } or , in the value part of an alias you have to
-# escape them by means of a backslash (\), this can lead to conflicts with the
-# commands \{ and \} for these it is advised to use the version @{ and @} or use
-# a double escape (\\{ and \\})
-
-ALIASES                =
-
-# Set the OPTIMIZE_OUTPUT_FOR_C tag to YES if your project consists of C sources
-# only. Doxygen will then generate output that is more tailored for C. For
-# instance, some of the names that are used will be different. The list of all
-# members will be omitted, etc.
-# The default value is: NO.
-
-OPTIMIZE_OUTPUT_FOR_C  = YES
-
-# Set the OPTIMIZE_OUTPUT_JAVA tag to YES if your project consists of Java or
-# Python sources only. Doxygen will then generate output that is more tailored
-# for that language. For instance, namespaces will be presented as packages,
-# qualified scopes will look different, etc.
-# The default value is: NO.
-
-OPTIMIZE_OUTPUT_JAVA   = NO
-
-# Set the OPTIMIZE_FOR_FORTRAN tag to YES if your project consists of Fortran
-# sources. Doxygen will then generate output that is tailored for Fortran.
-# The default value is: NO.
-
-OPTIMIZE_FOR_FORTRAN   = NO
-
-# Set the OPTIMIZE_OUTPUT_VHDL tag to YES if your project consists of VHDL
-# sources. Doxygen will then generate output that is tailored for VHDL.
-# The default value is: NO.
-
-OPTIMIZE_OUTPUT_VHDL   = NO
-
-# Set the OPTIMIZE_OUTPUT_SLICE tag to YES if your project consists of Slice
-# sources only. Doxygen will then generate output that is more tailored for that
-# language. For instance, namespaces will be presented as modules, types will be
-# separated into more groups, etc.
-# The default value is: NO.
-
-OPTIMIZE_OUTPUT_SLICE  = NO
-