path: root/docs/manual.md

## Textadept 11.1 Manual

**Contents**

1. [Introduction](#introduction)
2. [Getting Started](#getting-started)
3. [User Interface](#user-interface)
4. [Working with Files and Projects](#working-with-files-and-projects)
5. [Adept Editing](#adept-editing)
6. [Compile, Run, Build, and Test](#compile-run-build-and-test)
7. [Modules](#modules)
8. [Themes](#themes)
9. [Scripting](#scripting)
10. [Compiling](#compiling)
11. [Appendix](#appendix)

--------------------------------------------------------------------------------
### Introduction
--------------------------------------------------------------------------------

#### Overview

![Textadept](images/textadept.png)

Textadept is a fast, minimalist, and remarkably extensible cross-platform text
editor for programmers. Written in a combination of C and [Lua][] and
relentlessly optimized for speed and minimalism over the last 12+ years,
Textadept is an ideal editor for programmers who want endless extensibility
without sacrificing speed and disk space, and without succumbing to code bloat
and a superabundance of features. The application has both a graphical user
interface (GUI) version that runs in a desktop environment, and a terminal
version that runs within a terminal emulator.

[Lua]: https://www.lua.org

Textadept is _fast_. It starts up instantly and has a very responsive user
interface. C code is about as fast as you can get, and Lua is widely regarded as
being one of the fastest scripting languages available.

Textadept is minimalist. Not only is this evident in the editor's appearance,
but its C core is limited to around 2000 lines of code and its Lua extension
code tries to avoid going beyond 4000 lines. After more than 12 years of
development, Textadept contains [roughly the same amount of code][] since its
inception while significantly improving year after year.

[roughly the same amount of code]: index.html#plots

Textadept is remarkably extensible. It was designed to be that way from the
beginning; the editor's features came later. Most of Textadept's internals are
written in Lua: syntax highlighting, opening and saving files, and search and
replace, to name a few. Textadept gives you nearly complete control over the
entire application using Lua. Capabilities like navigating within the editor,
changing menus and key bindings on the fly, handling core events, and
highlighting the syntax of new programming languages are possible. The editor's
potential is seemingly limitless.

![Split Views](images/splitviews.png)

#### About This Manual

This manual uses the following typographical conventions:

* *Italic*: Used for filenames.
* `Constant width`: Used for environment variables, command line arguments,
  shell code, key bindings, and Lua code, including functions, tables, and
  variables.

Key bindings use the following modifier key representations:

Modifier|Windows, Linux, BSD|macOS|Terminal|
--------|-------------------|-----|--------|
Control |`Ctrl`             |`^`  |`^`     |
Alt     |`Alt`              |`⌥`  |`M-`    |
Command |N/A                |`⌘`  |N/A     |
Shift   |`Shift`            |`⇧`  |`S-`    |

This manual uses the following terminology:

* *buffer*: An object that contains editable text. Some other applications call
  this object a document or file.
* *view*: An object that displays a single buffer. Some other applications call
  this object a window.
* *caret*: The visual that represents the text insertion point. It is usually a
  blinking line.
* *module*: A package of Lua code that provides functionality for Textadept.
* *lexer*: A Lua module that highlights the syntax of source code written in a
  particular programming language. Textadept refers to a programming language by
  its lexer's name.

Finally, this manual assumes you are familiar enough with the [Lua][]
programming language that you can understand the simple code samples spread
throughout the manual's contents. If you would like to quickly get up to speed,
or need a refresher, the excerpt from [Lua Quick Reference][] may be of help.

[Lua Quick Reference]: https://orbitalquark.github.io/lua-quick-reference

#### ~/.textadept

Textadept stores all settings and user data in a local user directory that
varies, depending on the platform. This directory can also be configured using
command line arguments. On Windows systems, the default user directory is
*C:\Users\username\.textadept\\* or
*C:\Documents and Settings\username\.textadept\\*; on macOS, the default user
directory is */Users/username/.textadept/*; and on Linux and BSD, it is
*/home/username/.textadept/*. (Substitute *username* for your actual user name.)
From this point forward, the manual will use *~/.textadept/* in place of any
platform-specific user data directory.

There is a special file, *~/.textadept/init.lua*, that Textadept will create for
you if it does not already exist. This file is what you use to configure
Textadept, specify your preferences, and customize what the application does
when it starts. For example, you can use this file to set a color theme, specify
default buffer and view settings, change the settings of existing modules, load
custom modules, configure key bindings, extend menus, enhance support for file
types and programming languages, and run arbitrary Lua code. These topics will
be covered throughout the manual. Textadept's comprehensive [Lua API][] lists,
among other things, all configurable settings for buffers, views, and modules.
You can open your *~/.textadept/init.lua* file via `Ctrl+P` on Windows, Linux,
and BSD, `⌘,` on macOS, and `M-~` in the terminal version.

Here is a simple *~/.textadept/init.lua* for illustration:

    -- Adjust the default theme's font and size.
    if not CURSES then
      view:set_theme('light', {font = 'DejaVu Sans Mono', size = 12})
    end

    -- Always use tabs for indentation.
    buffer.use_tabs = true
    buffer.tab_width = 4

    -- Always strip trailing spaces on save, automatically highlight the current
    -- word, and use C99-style line comments in C code.
    textadept.editing.strip_trailing_space = true
    textadept.editing.highlight_words = textadept.editing.HIGHLIGHT_CURRENT
    textadept.editing.comment_string.ansi_c = '//'

    -- Load an external module and bind a key to it.
    local ctags = require('ctags')
    keys.f12 = ctags.goto_tag

    -- Recognize .luadoc files as Lua code.
    textadept.file_types.extensions.luadoc = 'lua'

    -- Change the run commands for Lua and Python
    textadept.run.run_commands.lua = 'lua5.1 "%f"'
    textadept.run.run_commands.python = 'python3 "%f"'

    -- Always use PEP-8 indentation style for Python files.
    events.connect(events.LEXER_LOADED, function(name)
      if name ~= 'python' then return end
      buffer.use_tabs = false
      buffer.tab_width = 4
    end)

**Note:** *~/.textadept/init.lua* must not call any functions that create
buffers and views (e.g. `ui.print()`, `io.open_file()`, and `buffer.new()`) at
file-level scope. Buffers and views can only be created within functions
assigned to keys, associated with menu items, or connected to events.

[Lua API]: api.html

--------------------------------------------------------------------------------
### Getting Started
--------------------------------------------------------------------------------

#### Requirements

In its bid for minimalism, Textadept depends on very little to run. On Windows
and macOS, it has no external dependencies. On Linux and BSD, the GUI version
depends only on [GTK][] (a cross-platform GUI toolkit) version 2.24 or later
(circa early 2011), and the terminal version depends only on a wide-character
implementation of curses like [ncurses][](w). Most Linux and BSD systems either
already have these dependencies installed, or they are readily available from a
package manager.

Windows XP and Mac OSX 10.7 (Lion) are the minimum required operating systems.
Linux and BSD have no defined minimum.

[GTK]: https://gtk.org
[ncurses]: https://invisible-island.net/ncurses/ncurses.html

#### Download

Textadept releases can be found [here][1]. Select the appropriate package for
your platform. A comprehensive list of changes between releases can be found
[here][2]. You can also download a separate set of modules that provide extra
features and functionality to the core application.

**Windows Note:** antivirus software may flag the Windows package as containing
a virus or malware. This is a false-positive, likely due to Textadept's terminal
version executable, which is a console application.

The following table lists Textadept's approximate download and installation size
for each platform.

Platform|Download Size|Installed Size
--------|-------------|--------------
Linux   |4 MB         |11 MB
macOS   |11 MB        |35 MB (12 MB without bundled GTK Runtime)
Windows |16 MB        |41 MB (23 MB without bundled GTK Runtime)

**Note:** each platform package contains two executables, one for the GUI
version of Textadept, and one for the terminal version.

[1]: https://github.com/orbitalquark/textadept/releases
[2]: changelog.html

#### Installation

Installing Textadept is simple and easy. You do not need administrator
privileges. On Windows, Linux, and BSD, simply unpack the archive anywhere. On
macOS, unpack the archive and move *Textadept.app* to your user or system
*Applications/* directory like any other macOS application. The macOS archive
also contains a *ta* script for launching Textadept from the command line. You
can put this script somewhere in your `$PATH` (e.g. */usr/local/bin/*), but this
is completely optional.

If you downloaded Textadept's extra set of modules, you can unpack its contents
into Textadept's directory (thus merging the *modules/* directories) on Windows,
Linux, and BSD. On macOS, it is recommended to create a *~/.textadept/*
directory (if it does not already exist) and unpack the modules there (thus
creating or merging the *modules/* directory).

**Note:** Textadept generally does not auto-load [modules](#modules), so you
will need to load at least some of those extra modules manually. For example, in
your *~/.textadept/init.lua*:

    require('ctags')
    require('file_diff')
    require('spellcheck')

#### Updating

Textadept releases typically occur on the first day of the month every 1-2
months. There is no auto-update process. (Textadept does not connect to the
internet; it's just a text editor.) Simply download the new version and copy its
contents into your current installation, overwriting any existing files and
directories.

#### Running

![Linux](images/linux.png)
  
![macOS](images/macosx.png)
  
![Win32](images/win32.png)
  
![curses](images/ncurses.png)

Run Textadept on Windows by double-clicking *textadept.exe* or
*textadept-curses.exe*. On macOS, double-click *Textadept.app* or invoke the
*ta* script from the command line. On Linux and BSD, invoke *textadept* or
*textadept-curses* from a file browser, run dialog, terminal, etc.

For convenience, you can create shortcuts to the executables on the Windows
Desktop, Start Menu, Quick Launch toolbar, etc. On macOS, you can pin the app to
your dock. On Linux and BSD, you can create a symbolic link to the executables
from somewhere in your `$PATH` (e.g. */usr/local/bin/*) or make a GNOME, KDE,
XFCE, etc. button or menu launcher. Textadept's *src/textadept.desktop* and
*src/textadept-curses.desktop* files may be of help.

Textadept accepts a variety of command line arguments, which are listed in the
table below.

Option             |Arguments|Description
-------------------|:-------:|-----------
`-e`, `--execute`  |    1    |Run the given Lua code
`-f`, `--force`    |    0    |Forces unique instance
`-h`, `--help`     |    0    |Shows this<sup>a</sup>
`-l`, `--line`     |    1    |Jumps to a line in the previously opened file
`-n`, `--nosession`|    0    |No state saving/restoring functionality
`-s`, `--session`  |    1    |Loads the given session on startup
`-u`, `--userhome` |    1    |Sets alternate user data directory
`-v`, `--version`  |    0    |Prints version and copyright info<sup>a</sup>

<sup>a</sup>The terminal version does not support these.

You can add your own command line arguments using [`args.register()`][]. For
example, in your *~/.textadept/init.lua*:

    args.register('-r', '--read-only', 0, function()
      events.connect(events.FILE_OPENED, function()
        buffer.read_only = true -- make all opened buffers read-only
      end)
      textadept.menu.menubar = nil -- hide the menubar
    end, "Read-only mode")

[`args.register()`]: api.html#args.register

Textadept can also open files and projects using the command line. For example:

    textadept /path/to/file1 ../relative/path/to/file2
    textadept /path/to/project/ relative/path/to/file1 relative/file2

Unless a filename is specified as an absolute path, Textadept assumes it is
relative to the application's current working directory (cwd). Textadept's cwd
is initially the command line's cwd. (If Textadept is not being run from the
command line, its cwd is unspecified.) If a project directory is specified, it
becomes Textadept's cwd. (Textadept does not open all files in that directory.)
If multiple project directories are specified, the last one becomes the cwd.

By default, Textadept saves its state when it exits. (This state consists of
buffers and split views that are open, the list of recently opened files,
the application window's size and maximized state, etc.) If Textadept is not
given any files or projects to open, it will try to restore its state at last
exit.

**Tip:** you can explicitly tell Textadept to load a session by name using the
`-s` or `--session` command line argument. You can disable session functionality
using `-n` or `--nosession`. Session files are stored in *~/.textadept/*, and
the default session name is "session".

The GUI version of Textadept is a single-instance application. This means that
after you start Textadept, any time you invoke it again (e.g. opening a file
from a file browser or command line), the action happens in the original
instance. If you want to run separate instances of Textadept, pass the `-f` or
`--force` command line flag. On Windows, you can create a shortcut to
*textadept.exe* that passes this flag and use that shortcut to run Textadept. On
Linux and BSD, you can set up your button or menu launchers to pass the flag to
the *textadept* executable.

Textadept can be run as a portable application. This is useful if, for example,
you want to install Textadept onto a flash drive and take it with you for use on
multiple machines. Normally, all settings and user data is stored in
*~/.textadept/* (a local user directory that varies, depending on the platform).
However, this user directory can be controlled using the `-u` or `--userhome`
command line argument. For example, invoking *textadept.exe* with the command
line arguments `-u userdata` will read from and store settings and user data to
a *userdata/* directory located inside an installation of Textadept. You can
create a Windows shortcut that passes these command line arguments to the
Textadept executable and use that shortcut to run Textadept portably.

Textadept's user interface has been translated into a few different languages.
When the application starts, it attempts to auto-detect your language settings
by reading from the `$LANG` environment variable. If Textadept cannot determine
what language to use, or if it does not support your language, it falls back on
English. You can manually set your locale by copying one of the locale
configuration files from Textadept's *core/locales/* to your *~/.textadept/*
directory and renaming it *locale.conf*. If you would like to translate
Textadept into your language, please translate the English messages in
*core/locale.conf* and send me (see README.md) the modified file for inclusion
in a future release.

**macOS Tip:** by default, macOS does not allow GUI applications like
*Textadept.app* to see shell environment variables like `$PATH`. (The terminal
version is unaffected.) Consequently, any features that utilize programs
contained in `$PATH` (e.g. the programs in */usr/bin/* or */usr/local/bin/*)
will not find those programs. In order to work around this, Textadept
automatically invokes a user-created *~/.textadept/osx_env.sh* file when the
application starts. This script should export all of the environment variables
you need Textadept to see. For example:

    export PATH=$PATH

**Linux Note:** providing a single binary that runs on all Linux systems proves
challenging, since the versions of software installed vary widely from
distribution to distribution. If you get errors like:

  * `error while loading shared libraries: <lib>: cannot open shared object
    file: No such file or directory`
  * `/<path>/libc.so.6: version 'GLIBC_<version>' not found`

you will need to [compile](#compiling) Textadept manually for your system, which
is a very straightforward and easy process.

--------------------------------------------------------------------------------
### User Interface
--------------------------------------------------------------------------------

![UI](images/ui.png)

Textadept's user interface is sleek and simple. It consists of a menu bar, tab
bar, editor view, and statusbar. There is also a find & replace pane and a
command entry, though Textadept initially hides them both.

Textadept's titlebar shows the name and path of the current, active buffer. A
'\*' character, if present, indicates there are unsaved changes in that buffer.

#### Menu

The GUI version of Textadept has a completely customizable menu that provides
access to nearly all of the application's editing features.

**Tip:** Textadept is largely a keyboard-driven application, so nearly every
menu item has a key binding. For at least the GUI version in the English locale
on Windows, Linux, and BSD, each menu and menu item also has a unique mnemonic
that can be used to activate it. For example, `Alt+E` accesses the "Edit" menu,
`S` opens the "Select" sub-menu, and `L` invokes the menu item that selects the
current line.

Textadept's menu is also accessible in the form of a searchable dialog via
`Ctrl+Shift+E` on Windows, Linux, and BSD, `⌘⇧E` on macOS, and `M-S-C` in the
terminal version. (Despite the fact that the terminal version does not have a
menu, it does have this dialog.) Typing part of the name of any command in the
dialog filters the list, with spaces being wildcards. The arrow keys move the
selection up and down. Pressing `Enter`, selecting `OK`, or double-clicking on a
command invokes it. (The terminal requires pressing `Enter`.) This feature is an
alternative to navigating the menus or remembering key bindings. It can also be
used to quickly look up key bindings for particular commands.

**Note:** for commands that have more than one key binding, only one of those
bindings is shown in the menu and dialog, and that binding is randomly chosen.

You can extend Textadept's menu with your own menus, sub-menus, and menu items
by modifying the [`textadept.menu.menubar`][] table. Any modifications will show
up in the selection dialog mentioned previously, even in the terminal version.
For example, in your *~/.textadept/init.lua*:

    local tools = textadept.menu.menubar[_L['Tools']]
    tools[#tools + 1] = {''} -- separator
    tools[#tools + 1] = {'Reset L_ua State', reset}

[`textadept.menu.menubar`]: api.html#textadept.menu.menubar

#### Tab Bar

The GUI version of Textadept has a tab bar that displays all of Textadept's open
buffers by name, though it is only visible when two or more buffers are open. A
'\*' character, if present, indicates there are unsaved changes in the marked
buffer. There is only one tab bar for the entire application, even if there are
multiple split views. When two or more views are open, the state of the tab bar
applies only to the active view, and using the tab bar to switch between files
also applies only to that view. Right-clicking on the tab bar brings up a
configurable context menu that is defined by
[`textadept.menu.tab_context_menu`][]. You can turn off the tab bar by setting
[`ui.tabs`][]. For example, in your *~/.textadept/init.lua*:

    ui.tabs = false

[`textadept.menu.tab_context_menu`]: api.html#textadept.menu.tab_context_menu
[`ui.tabs`]: api.html#ui.tabs

Cycle to the next buffer via `Ctrl+Tab` on Windows, Linux, and BSD, `^⇥` on
macOS, and `M-N` in the terminal version. Cycle to the previous buffer via
`Ctrl+Shift+Tab`, `^⇧⇥`, and `M-P`.

**Note:** Textadept does not currently support rearranging tabs (e.g. via drag
and drop).

The tab bar is also accessible in the form of a searchable dialog via `Ctrl+B`
on Windows, Linux, and BSD, `⌘B` on macOS, and `M-B` or `M-S-B` in the terminal
version. (Despite the fact that the terminal version does not have a tab bar, it
does have this dialog.) The dialog displays a list of currently open buffers.
Typing part of any filename filters the list, with spaces being wildcards. The
arrow keys move the selection up and down. Pressing `Enter`, selecting `OK`, or
double-clicking on a buffer switches to it. (The terminal requires pressing
`Enter`.) This feature is particularly useful when many files are open, and
navigating through the tab bar is tedious.

![Buffer Browser](images/bufferbrowser.png)
&nbsp;&nbsp;
![Buffer Browser Filtered](images/bufferbrowserfiltered.png)

By default, the list shows buffers in the same order as the tab bar (the most
recently opened buffers are shown towards the bottom). You can configure the
list to show the most recently viewed buffers first by changing the key binding.
For example, in your *~/.textadept/init.lua*:

    keys['ctrl+b'] = function() ui.switch_buffer(true) end

#### Editor View

The editor view is where you will spend most of your time in Textadept. You can
split it vertically and horizontally as many times as you like, and you can view
the same buffer in two or more separate views. Lua also has near complete
control over all views. The [`buffer`][] and [`view`][] documentation lists
everything you can do with buffers and views directly. Right-clicking inside a
view brings up a configurable context menu that is defined by
[`textadept.menu.context_menu`][].

Split views can be dynamically resized by clicking and dragging on the splitter
bar that separates them. The following key bindings apply for split views:

* Split a view horizontally into top and bottom views via `Ctrl+Alt+S` or
  `Ctrl+Alt+H` on Windows, Linux, and BSD, `^S` on macOS, and `M-^V S` in the
  terminal version.
* Split a view vertically into side-by-side views via `Ctrl+Alt+V` on Windows,
  Linux, and BSD, `^V` on macOS, and `M-^V V` in the terminal version.
* Cycle to the next split view via `Ctrl+Alt+N` on Windows, Linux, and BSD,
  `^⌥⇥` on macOS, and `M-^V N` in the terminal version.
* Cycle to the previous split view via `Ctrl+Alt+P` on Windows, Linux, and BSD,
  `^⌥⇧⇥` on macOS, and `M-^V P` in the terminal version.
* Grow or shrink a view via `Ctrl+Alt++` or `Ctrl+Alt+-`, respectively, on
  Windows, Linux, and BSD; `^+` or `^-`, respectively, on macOS; and `M-^V +` or
  `M-^V -` in the terminal version.
* Unsplit the current view by removing its complement view(s) via `Ctrl+Alt+W`
  on Windows, Linux, and BSD, `^W` on macOS, and `M-^V W` in the terminal
  version.
* Unsplit the current view by removing all other views via `Ctrl+Alt+Shift+W` on
  Windows, Linux, and BSD, `^⇧W` on macOS, and `M-^V S-W` in the terminal
  version.

**Note:** depending on the split sequence, the order when cycling between views
may not be linear.

**Terminal version note:** `M-^V` is the key chain prefix for split views. Press
and release the prefix, and then type the next key in the chain by itself in
order to perform the split view action.

[`buffer`]: api.html#buffer
[`view`]: api.html#view
[`textadept.menu.context_menu`]: api.html#textadept.menu.context_menu

#### Find & Replace Pane

The find & replace pane is a compact, full-featured pane that allows you to
quickly search through files and directories. The pane is available only when
you need it and quickly gets out of your way when you do not, minimizing
distractions.

You can summon the find & replace pane via `Ctrl+F` on Windows, Linux and BSD,
`⌘F` on macOS, and `M-F` or `M-S-F` in the terminal version. It has the usual
find and replace functionality you would expect, along with "Match Case",
"Whole Word", "[Regex](#regex-and-lua-pattern-syntax)", and "In Files" options.
The pane also stores find and replace history, up to 10 entries for each. As you
search, Textadept can automatically highlight all instances of found text in the
current buffer by setting [`ui.find.highlight_all_matches`][]. For example, in
your *~/.textadept/init.lua*:

    ui.find.highlight_all_matches = true

**Note:** Textadept does not support multi-line regex searches.

While the pane is open in the GUI, the following key bindings apply:

* Perform "Find Next" and "Find Prev" in the "Find" entry via `Enter` and
  `Shift+Enter`, respectively.
* Perform "Replace" and "Replace All" in the "Replace" entry via `Enter` and
  `Shift+Enter`, respectively. When the "Regex" find option is enabled,

  + `\`*`n`* in the "Replace" entry represents the *n*th captured matching
    region's text, and `\0` represents all matched text.
  + `\U` and `\L` converts everything up to the next `\L`, `\U`, or `\E` to
    uppercase and lowercase, respectively. (`\E` turns off conversion.)
  + `\u` and `\l` converts the next character to uppercase and lowercase,
    respectively. These may appear within `\U` and `\L` constructs.

* For at least the English locale, toggle the find options using their button
  mnemonics: `Alt+M`, `Alt+W`, `Alt+X`, `Alt+I` on Windows, Linux, and BSD, and
  `⌘M`, `⌘W`, `⌘X`, and `⌘I`, respectively, on macOS.
* Cycle through find/replace history via `Up` and `Down` on Windows, Linux, BSD,
  and the terminal version, and `⇡` and `⇣` on macOS.
* Hide the pane via `Esc`.

While the pane is open in the terminal version, the following key bindings
apply:

* Switch between "Find" and "Replace" entries via `Down` and `Up`.
* Toggle between "Find Next" and "Find Prev" in the "Find" entry via `Tab`.
* Toggle between "Replace" and "Replace All" in the "Replace" entry via `Tab`.
* Perform the highlighted find/replace action via `Enter`.
* Toggle the find options via `F1`, `F2`, `F3`, and `F4`.
* Cycle through find/replace history via `^P` and `^N`.
* Erase the contents of the focused entry via `^U`.
* Hide the pane via `Esc`.

When the pane is closed, you can quickly perform "Find Next", "Find Prev",
"Replace", and "Replace All" via `Ctrl+G`, `Ctrl+Shift+G`, `Ctrl+Alt+R`, and
`Ctrl+Alt+Shift+R`, respectively, on Windows, Linux, and BSD; `⌘G`, `⌘⇧G`, `^R`,
and `^⇧R`, respectively, on macOS; and `M-G`, `M-S-G`, `M-R`, and `M-S-R` in the
terminal version.

**Tip:** by default, "Replace All" replaces all text in the buffer. Selecting a
contiguous block of text and then performing "Replace All" replaces all text
in that selection only. Textadept does not currently support "Replace All"
within non-contiguous selections (e.g. multiple selections).

[`ui.find.highlight_all_matches`]: api.html#ui.find.highlight_all_matches

##### Find in Files

Textadept can search for text within multiple files and directories via
`Ctrl+Shift+F` on Windows, Linux, and BSD, and `⌘⇧F` on macOS. (The terminal
version does not have a default key binding for finding in files.) Invoking
"Find Next" prompts you for a directory to search in. The "Replace" entry has
been substituted for a "Filter" entry that contains files and directories to
include or exclude from the search.

A filter consists of a comma-separated list of
[Lua patterns](#regex-and-lua-pattern-syntax) that match filenames and
directories to include or exclude. Patterns are inclusive by default. Exclusive
patterns begin with a '!'. If no inclusive patterns are given, any filename is
initially considered. As a convenience, file extensions can be specified
literally instead of as a Lua pattern (e.g. '.lua' vs. '%.lua$'), and '/' also
matches the Windows directory separator ('[/\\]' is not needed). The default
filter excludes many common binary files and version control directories from
searches.

**Tip:** Textadept keeps track of filters set per-directory. You can also set
per-directory filters in Lua by modifying [`ui.find_in_files_filters`][]. For
example, in your *~/.textadept/init.lua*:

    -- Only search in certain source directories.
    ui.find.find_in_files_filters['/path/to/project'] = {'/include', '/src'}

After performing a "Find in Files" search, a temporary buffer lists the search
results. You can use the arrow keys to navigate within the list and press
`Enter` to jump to a result's location in its respective file. You can also
double-click on results or jump to the next or previous result via `Ctrl+Alt+G`
or `Ctrl+Alt+Shift+G`, respectively, on Windows, Linux, and BSD; and `^⌘G` or
`^⌘⇧G`, respectively, on macOS. (The terminal version does not have default key
bindings for these actions.)

![Find in Files](images/findinfiles.png)

[`ui.find_in_files_filters`]: api.html#ui.find.find_in_files_filters

##### Incremental Find

Textadept searches for text incrementally as you type when you summon the find &
replace pane via `Ctrl+Alt+F` on Windows, Linux, and BSD, `^⌘F` on macOS, and
`M-^F` in the terminal version. All of the find options apply except for
"In Files".

#### Command Entry

The versatile command entry has many different roles. Its primary role is to
execute Lua commands and interact with Textadept's internal Lua state. In
another context it filters text through shell commands. [Lua extensions][] allow
it to do even more. Like the find & replace pane, the command entry pops in and
out as you wish. Each role has its own history that can be cycled through via
the `Up` and `Down` key bindings on Windows, Linux, BSD, and the terminal
version, and `⇡` and `⇣` on macOS.

[Lua extensions]: api.html#ui.command_entry

##### Lua Command Entry

![Command Entry](images/commandentry.png)

You can open the Lua command entry via `Ctrl+E` on Windows, Linux, and BSD,
`⌘E` on macOS, and `M-C` in the terminal version. It acts very similarly to
Lua's interactive prompt. Type in the Lua command or code to run and press
`Enter` to invoke or run it. Textadept's [Lua API][] contains all of the
application's built-in commands. For convenience, the contents of the
[`buffer`][], [`view`][], [`ui`][], and [`textadept`][] tables are considered to
be global variables, the first parameter to `buffer` and `view` functions may be
omitted, and function call parentheses can also be omitted. For example, instead
of entering `buffer:append_text('foo')`, you can enter `append_text('foo')`.
Instead of `view:split()`, you can simply use `split`. These convenience
facilities are not available in normally executed Lua code, such as code in
*~/.textadept/init.lua*.

**Warning:** if you try to cause instability of Textadept's Lua state, you will
probably succeed, so be careful.

The following key bindings apply in the Lua command entry:

* Show a documentation popup for the command under or behind the caret via
  `Ctrl+H` on Windows, Linux, and BSD, `^H` on macOS, and `M-H` or `M-S-H` in
  the terminal version.
* Show completion candidates for Lua variables, tables, functions, and fields
  via `Tab` on Windows, Linux, BSD, and the terminal version, and `⇥` on macOS.
  Use the arrow keys to make a selection and press `Enter` to insert it.

![Command Completion](images/commandentrycompletion.png)

You can specify on the command line Lua commands and code to run on startup
using the `-e` and `--execute` command line argument. This is useful when you
want to run dynamic commands that do not belong in *~/.textadept/init.lua*.

**Tip:** a side-effect of single-instance functionality in the GUI version of
Textadept is that you can remotely control the original instance of Textadept.
For example:

    ta ~/.textadept/init.lua &
    ta -e "events.emit(events.FIND, 'require')"

This will search for the first instance of the word "require" in the current
file.

[Lua API]: api.html
[`buffer`]: api.html#buffer
[`view`]: api.html#view
[`ui`]: api.html#ui
[`textadept`]: api.html#textadept

##### Shell Command Entry and Filtering Text

You can filter text through shell commands via `Ctrl+|` on Windows, Linux, and
BSD, `⌘|` on macOS, and `^\` in the terminal version. An example would be
running the shell command `sort`, which accepts lines in a buffer as standard
input (stdin), sorts those lines, and then emits them to standard output
(stdout), which Textadept replaces the original input text with.
[`textadept.editing.filter_through()`][] describes how this feature determines
stdin.

[`textadept.editing.filter_through()`]: api.html#textadept.editing.filter_through

#### Statusbar

The statusbar consists of two sections. The left section displays temporary
status messages, while the right section shows buffer status information. Buffer
status information includes:

* The current line and column number.
* The lexer language name.
* The line ending mode, or EOL mode, which is either CRLF ("\r\n") or LF ('\n').
  Line endings are the characters that separate lines.
* The indentation settings, which are a combination of an indentation character
  (either a tab or a space) and an indentation size (a measure of how many space
  characters are in one level of indentation). If tabs are used for indentation,
  then the indentation size is the number of space characters to draw for each
  tab character.
* The buffer's encoding. File and buffer encoding specifies how to interpret
  text bytes for display.

![Document Statusbar](images/docstatusbar.png)

--------------------------------------------------------------------------------
### Working with Files and Projects
--------------------------------------------------------------------------------

Textadept allows you to open files using a variety of methods:

* Open, using a standard file chooser dialog, one or more files in a single
  directory via `Ctrl+O` on Windows, Linux, and BSD, `⌘O` on macOS, and `^O` in
  the terminal version.
* Open, using a quick open dialog, one or more files in the current project or
  Textadept's current working directory via `Ctrl+Alt+Shift+P` on Windows,
  Linux, and BSD, `^⌘⇧P` on macOS, and `M-^P` in the terminal version. Typing
  part of any filename filters the list, with spaces being wildcards. The arrow
  keys move the selection up and down. Holding down `Shift` while pressing the
  arrow keys selects multiple files, as does holding down `Ctrl` while clicking.
  Pressing `Enter` or selecting `OK` opens all selected files. Double-clicking
  on a single file opens it. (The terminal requires pressing `Enter`.)
* Open, using a quick open dialog, one or more files in the directory of the
  currently opened file via `Ctrl+Alt+Shift+O` on Windows, Linux, and BSD,
  `^⌘⇧O` on macOS, and `M-S-O` in the terminal version.
* Open a file by dragging it from a file manager and dropping it into one of
  Textadept's views.
* Open a recently opened file from a list of recent files via `Ctrl+Alt+O` on
  Windows, Linux, and BSD, `^⌘O` on macOS, and `M-^O` in the terminal version.
* Open, using a quick open dialog, one or more files in *~/.textadept/* via
  `Ctrl+U` on Windows, Linux, and BSD, `⌘U` on macOS, and `^U` in the terminal
  version.
* Reopen the currently opened file, discarding any unsaved changes, via
  `Ctrl+Shift+O` on Windows, Linux, and BSD, `⌘⇧O` on macOS, and `M-O` in the
  terminal version. Textadept will prompt you to reload a file if the editor
  detects it has been modified externally.

![Quick Open](images/snapopen.png)

When it comes to projects, Textadept's only concept of a project is a parent
directory under a recognized form of version control (Git, Mercurial, SVN,
Bazaar, and Fossil). There is no "Open Project" action. Textadept can work with
multiple projects at once, since the current project depends largely on context.
The current project is determined as follows:

1. If the current buffer is a file, its parent directory is searched for a
   version control directory. If none is found, that directory's parent
   directory is searched next, and so on. If a version control directory is
   found, its parent directory is the current project.
2. If Textadept's current working directory (cwd) contains a version control
   directory, that cwd is the current project. Otherwise, the cwd's parent
   directory is searched, just like in step 1.
3. If no version control directory is found, there is no current project.

**Tip:** you can specify Textadept's current working directory by passing it on
the command line when running the application. This effectively starts Textadept
with a "default project".

By default, Textadept's quick open dialog displays nearly all types of files,
and only the first 1000 files it finds. You can assign a project or
directory-specific filter that indicates which files to display for that project
or directory by modifying [`io.quick_open_filters`][], and you can specify a
different maximum file list size that applies to all projects and directories by
setting [`io.quick_open_max`][]. For example, in your *~/.textadept/init.lua*:

    io.quick_open_filters['/path/to/project'] = {'/include', '/src'}
    io.quick_open_max = 10000 -- support huge projects

A filter consists of a comma-separated list of
[Lua patterns](#regex-and-lua-pattern-syntax) that match filenames and
directories to include or exclude. Patterns are inclusive by default. Exclusive
patterns begin with a '!'. If no inclusive patterns are given, any filename is
initially considered. As a convenience, file extensions can be specified
literally instead of as a Lua pattern (e.g. '.lua' vs. '%.lua$'), and '/' also
matches the Windows directory separator ('[/\\]' is not needed). The default
filter excludes many common binary files and version control directories from
searches.

You can mimic a more traditional approach to projects by saving and loading
project-specific sessions via the "File > Save Session..." and
"File > Load Session..." menu items, respectively. A session can be loaded on
startup using the `-s` or `--session` command line argument.

[`io.quick_open_filters`]: api.html#io.quick_open_filters
[`io.quick_open_max`]: api.html#io.quick_open_max

##### Language

When Textadept opens a file, it automatically attempts to identify the
programming language associated with that file and assigns a lexer to perform
syntax highlighting of the file's contents. The identification process is as
follows:

1. The first line of the file is checked against any Lua patterns in
   [`textadept.file_types.patterns`][]. If there is a match, the lexer
   associated with that matching pattern is used.
2. The file's extension is checked against any of the extensions in
   [`textadept.file_types.extensions`][]. If there is a match, the lexer
   associated with that matching extension is used. If the file does not have
   an extension, the entire file name is used in the check.

You can associate first line patterns, file extensions, and file names with
lexers by modifying [`textadept.file_types.patterns`][] and
[`textadept.file_types.extensions`][]. For example, in your
*~/.textadept/init.lua*:

    textadept.file_types.patterns['^#!.+/zsh'] = 'bash'
    textadept.file_types.extensions.luadoc = 'lua'

Textadept has lexers for more than 100 different programming languages and
recognizes hundreds of file types. In the event that your programming language
is not understood, you can write a [lexer][] for it, place that lexer in your
*~/.textadept/lexers/* directory, and add an extension and/or pattern for it.

For a given lexer name, Textadept attempts to find, in order, that lexer from
the following locations:

1. Your *~/.textadept/lexers/* directory.
2. Textadept's *lexers/* directory.

**Tip:** placing lexers in your user data directory avoids the possibility of
you overwriting them when you update Textadept. These lexers also take
precedence over the ones installed with Textadept.

You can manually change a buffer's lexer via `Ctrl+Shift+L` on Windows, Linux,
and BSD, `⌘⇧L` on macOS, and `M-S-L` in the terminal version. Typing part of a
lexer name in the dialog filters the list, with spaces being wildcards. The
arrow keys move the selection up and down. Pressing `Enter`, selecting `OK`, or
double-clicking on a lexer assigns it to the current buffer. (The terminal
requires pressing `Enter`.)

[`textadept.file_types.patterns`]: api.html#textadept.file_types.patterns
[`textadept.file_types.extensions`]: api.html#textadept.file_types.extensions
[lexer]: api.html#lexer

##### Encoding

Textadept has the ability to work with files encoded in one of many different
encodings, but by default it only attempts to read UTF-8, ASCII, CP1252, and
UTF-16 files, in that order. If you work with files that have other encodings,
you will need to add them to [`io.encodings`][], Textadept's known encoding
list, before attempting to open one. For example, in your
*~/.textadept/init.lua*:

    io.encodings[#io.encodings + 1] = 'UTF-32'
    table.insert(io.encodings, 3, 'Macintosh') -- before CP1252

You can convert a buffer's encoding using the "Buffer > Encoding" menu or
[`buffer.set_encoding()`][]. You can extend the menu to include more encodings.
For example, in your *~/.textadept/init.lua*:

    local menu = textadept.menu.menubar[_L['Buffer']][_L['Encoding']]
    local encoding = 'UTF-32'
    menu[#menu + 1] = {encoding, function() buffer:set_encoding(encoding) end}

The default encoding for new buffers is UTF-8, due to its wide support in other
text editors and all modern operating systems.

[`io.encodings`]: api.html#io.encodings
[`buffer.set_encoding()`]: api.html#buffer.set_encoding

##### Buffer Settings

Textadept attempts to auto-detect a file's line end mode (EOL mode), falling
back on CRLF ("\r\n") by default on Windows, and LF ('\n') on all other
platforms. You can manually change the line ending mode using the
"Buffer > EOL Mode" menu.

Textadept does not attempt to auto-detect a file's indentation. The default
indentation setting is two spaces, but you can specify your preferred
indentation settings globally, and on a language-specific basis. For example,
in your *~/.textadept/init.lua*:

    -- Default indentation settings for all buffers.
    buffer.use_tabs = true
    buffer.tab_width = 8

    -- Indentation settings for individual languages.
    events.connect(events.LEXER_LOADED, function(name)
      if name == 'python' then
        buffer.use_tabs = false
        buffer.tab_width = 4
      elseif name == 'ruby' or name == 'yaml' then
        buffer.use_tabs = false
        buffer.tab_width = 2
      end
    end)

You can manually change a buffer's indentation using the following process:

1. Toggle between using tabs and spaces via `Ctrl+Alt+Shift+T` on Windows,
   Linux, and BSD, `^⇧T` on macOS, and `M-T` or `M-S-T` in the terminal version.
2. Set the indentation size via the "Buffer > Indentation" menu.
3. Optionally convert existing indentation to the new indentation settings via
   `Ctrl+Alt+I` on Windows, Linux, and BSD, `^I` on macOS, and `M-I` in the
   terminal version.

##### View Settings

Textadept normally does not wrap long lines into view, nor does it show
whitespace characters. You can toggle line wrapping for the current buffer via
`Ctrl+Alt+\` on Windows, Linux, and BSD, and `^\` on macOS. You can toggle
whitespace visibility for the current buffer via `Ctrl+Alt+Shift+S` on Windows,
Linux, and BSD, and `^⇧S` on macOS. Visible spaces are represented by dots, and
visible tabs are represented by arrows. (The terminal version does not have
default key bindings for either of these actions.)

The GUI version of Textadept can show small guiding lines based on indentation
level, and does so by default. You can toggle the visibility of these guides for
the current view via `Ctrl+Alt+Shift+I` on Windows, Linux, and BSD, and `^⇧I` on
macOS.

The GUI version of Textadept also allows you to temporarily increase or decrease
the font size in the current view. The following key bindings apply for this
feature:

* Increase the view's font size via `Ctrl+=` on Windows, Linux, and BSD, and
  `⌘=` on macOS.
* Decrease the view's font size via `Ctrl+-` on Windows, Linux, and BSD, and
  `⌘-` on macOS.
* Reset the view's font size to its normal value via `Ctrl+0` on Windows, Linux,
  and BSD, and `⌘0` on macOS.

--------------------------------------------------------------------------------
### Adept Editing
--------------------------------------------------------------------------------

Textadept implements most of the customary key bindings for navigating text
fields on each platform, including Bash-style bindings on macOS and in the
terminal version. The editor also implements most of the usual basic editing
key bindings (e.g. undo, redo, cut, copy, paste, etc.). All of Textadept's
navigation-related key bindings are listed in the "Movement" section of the
[key bindings list][]. Textadept's basic editing key bindings are listed in the
"Edit" section of that list. (They are also shown in the "Edit" menu.)

[key bindings list]: api.html#textadept.keys

#### Brace Matching, Auto-pair, and Typeover

Textadept automatically highlights matching brace characters when the caret is
over one of them: '(', ')', '[', ']', '{', or '}'. You can jump to the current
character's complement via `Ctrl+M` on Windows, Linux, and BSD, `^M` on macOS,
and `M-M` in the terminal version. You can add highlighting for '<' and '>' by
modifying [`textadept.editing.brace_matches`][]. For example, in your
*~/.textadept/init.lua*:

    textadept.editing.brace_matches[string.byte('<')] = true
    textadept.editing.brace_matches[string.byte('>')] = true

![Matching Braces](images/matchingbrace.png)

Since braces often go together in pairs, Textadept automatically inserts the
complement of opening brace characters you type, deletes that complement if you
press `Backspace`, and moves over the complement if you type it (as opposed to
inserting it again). Textadept also exhibits this behavior for single and double
quote characters ('&apos;' and '&quot;'). You can configure or disable this
behavior by modifying [`textadept.editing.auto_pairs`][] and
[`textadept.editing.typeover_chars`][]. For example, in your
*~/.textadept/init.lua*:

    -- Auto-pair and typeover '<' and '>'.
    textadept.editing.auto_pairs[string.byte('<')] = '>'
    textadept.editing.typeover_chars[string.byte('>')] = true

    -- Disable auto-pair and typeover.
    textadept.editing.auto_pairs = nil
    textadept.editing.typeover_chars = nil

[`textadept.editing.brace_matches`]: api.html#textadept.editing.brace_matches
[`textadept.editing.auto_pairs`]: api.html#textadept.editing.auto_pairs
[`textadept.editing.typeover_chars`]: api.html#textadept.editing.typeover_chars

#### Word Highlight

Textadept can be configured to automatically highlight all occurrences of the
word under the caret, or all occurrences of the selected word (e.g. a variable
name), by setting [`textadept.editing.highlight_words`][]. For example, in your
*~/.textadept/init.lua*:

    -- Highlight all occurrences of the current word.
    textadept.editing.highlight_words = textadept.editing.HIGHLIGHT_CURRENT
    -- Highlight all occurrences of the selected word.
    textadept.editing.highlight_words = textadept.editing.HIGHLIGHT_SELECTED

Pressing `Esc` clears highlighting. By default, Textadept does not perform any
automatic highlighting.

![Word Highlight](images/wordhighlight.png)

[`textadept.editing.highlight_words`]: api.html#textadept.editing.highlight_words

#### Autocompletion and Documentation

Textadept provides buffer-based word completion. It can also autocomplete
symbols for programming languages and display documentation for functions and
other symbols.

You can show word completion candidates for partially-typed words via
`Ctrl+Enter` on Windows, Linux, and BSD, `^Esc` on macOS, and `M-Enter` in the
terminal version. Continuing to type changes the suggested completion. Use the
arrow keys to navigate within the list and press `Enter` to insert the rest of
the selected word. By default, the list of completions comes from the current
buffer. You can configure Textadept to look in all open buffers by setting
[`textadept.editing.autocomplete_all_words`][]. For example, in
*~/.textadept/init.lua*:

    textadept.editing.autocomplete_all_words = true

![Word Completion](images/wordcompletion.png)

For languages that support it, you can show symbol completion candidates at the
current position via `Ctrl+Space` on Windows, Linux, and BSD, `⌥Esc` on macOS,
and `^Space` in the terminal version.

![Autocomplete Lua](images/adeptsense_lua.png)
&nbsp;&nbsp;&nbsp;&nbsp;
![Autocomplete Lua String](images/adeptsense_string.png)

Also for languages that support it, you can show any known documentation for the
current symbol via `Ctrl+H` on Windows, Linux, and BSD, `^H` on macOS, and `M-H`
or `M-S-H` in the terminal version. Textadept has built-in autocompletion and
documentation support for Lua and C, including for its own Lua API.

![Documentation](images/adeptsense_doc.png)

Textadept's framework for providing symbol autocompletion and documentation
relies on [autocompleter][] functions and [API files][], which are often
supplied by [language][] [modules](#modules). You can use this framework to
write your own autocompletion routines.

[`textadept.editing.autocomplete_all_words`]: api.html#textadept.editing.autocomplete_all_words
[autocompleter]: api.html#textadept.editing.autocompleters
[API files]: api.html#textadept.editing.api_files
[language]: api.html#_M

#### Text Selections

Textadept has three kinds of text selections: contiguous, multiple, and
rectangular.

You can create contiguous selections as follows:

* Make an arbitrary selection anchored at the caret by pressing the arrow keys,
  home/end, page up/down, etc. while holding down the `Shift` key, or by simply
  clicking and dragging the mouse.
* The terminal version can also make an arbitrary selection by entering
  selection mode via `^^` and using normal movement keys. This feature is
  available since some terminals do not recognize `Shift` with movement keys.
  While in selection mode, swap the start and end positions via `^]` in order to
  alter the selection from its opposite side. Exit selection mode by typing
  text, deleting text, performing an action that changes text, or by
  pressing `^^` again.
* Select the current word via `Ctrl+Shift+D` on Windows, Linux, and BSD, `⌘⇧D`
  on macOS, and `M-S-W` in the terminal version. Repeated use of this action
  selects subsequent occurrences of that word as additional (multiple)
  selections.
* Select the current line via `Ctrl+Shift+N` on Windows, Linux, and BSD, `⌘⇧N`
  on macOS, and `M-S-N` in the terminal version.
* Double click to select a word, and triple-click to select a line.
* Click and optionally drag within the line number margin to select whole lines.
* Select the current paragraph via `Ctrl+Shift+P` on Windows, Linux, and BSD,
  `⌘⇧P` on macOS, and `M-S-P` in the terminal version. Paragraphs are surrounded
  by one or more blank lines.
* Select all buffer text via `Ctrl+A` on Windows, Linux, and BSD, `⌘A` on macOS,
  and `M-A` in the terminal version.
* Select text between matching delimiters (parentheses, brackets, braces, single
  quotes, double-quotes, and back quotes) via `Ctrl+Shift+M` on Windows, Linux,
  and BSD, `^⇧M` on macOS, and `M-S-M` in the terminal version. Repeated use of
  this action toggles the selection of the delimiters themselves.
* Select between HTML/XML tags via `Ctrl+<` on Windows, Linux, and BSD, `⌘<` on
  macOS, and `M-<` in the terminal version.
* Select an HTML/XML tag via `Ctrl+>` on Windows, Linux, and BSD, and `⌘>` on
  macOS.

You can create multiple selections as follows:

* Add another selection by holding down `Ctrl`, clicking, and optionally
  dragging the mouse over a range of text.
* Select as an additional selection the next occurrence of the current word via
  `Ctrl+Shift+D` on Windows, Linux, and BSD, `⌘⇧D` on macOS, and `M-S-W` in the
  terminal version.

Textadept mirrors any typed text at each selection.

You can create a rectangular selection as follows:

* Press the arrow keys, home/end, or page up/down, while holding down
  `Alt+Shift` on Windows, Linux, and BSD, `⌥⇧` on macOS, and `M-S-` in the
  terminal version.
* Click and drag the mouse while holding down the `Alt` key on Windows, Linux,
  and BSD, and `⌥` on macOS.
* Click and drag the mouse without holding down any modifiers (thus making a
  normal, multi-line selection), press and hold down the `Alt` key on Windows,
  Linux, and BSD, `⌥` on macOS, and `M-` in the terminal version, and then
  continue dragging the mouse. This feature is available because some window
  managers in Linux consume `Alt+Shift` + arrow keys and `Alt` + mouse drag.

You are permitted to create a zero-width rectangular selection that spans
multiple lines, and for this kind of selection, Textadept mirrors any typed text
on all of those lines.

![Rectangular Selection](images/rectangularselection.png)
&nbsp;&nbsp;&nbsp;&nbsp;
![Rectangular Edit](images/rectangularselection2.png)

#### Text Transformations

Textadept can apply many different transformations to the current word, line,
and selected text.

* Enclose the current word or selected text within delimiters like parentheses,
  braces, brackets, single quotes, double quotes, or HTML/XML tags using the key
  bindings listed in the "Edit > Selection" submenu.
* Convert the selected text to upper or lower case via `Ctrl+Alt+U` or
  `Ctrl+Alt+Shift+U`, respectively, on Windows, Linux, and BSD; `^U` or `^⇧U`,
  respectively, on macOS; and `M-^U` or `M-^L` in the terminal version.
* Increase or decrease the indentation of the selected lines via `Tab` or
  `Shift+Tab`, respectively, on Windows, Linux, and BSD; `⇥` or `⇧⇥`,
  respectively on macOS; and `Tab` or `S-Tab` in the terminal version. You do
  not have to select whole lines; selecting any part of a line is sufficient.
* Move the current or selected line(s) up or down via `Ctrl+Shift+Up` or
  `Ctrl+Shift+Down`, respectively, on Windows, Linux, and BSD; `^⇧⇡` or `^⇧⇣`,
  respectively, on macOS; and `S-^Up` or `S-^Down` in the terminal version. You
  do not have to select whole lines; selecting any part of a line is sufficient.
* Comment out code on the current or selected line(s) via `Ctrl+/` on Windows,
  Linux, and BSD, `⌘/` on macOS, and `M-/` in the terminal version. You do not
  have to select whole lines; selecting any part of a line is sufficient.

You can auto-enclose selected text between any typed punctuation character
(taking into account [`textadept.editing.auto_pairs`][]) by setting
[`textadept.editing.auto_enclose`][]. For example, in your
*~/.textadept/init.lua*:

    textadept.editing.auto_enclose = true

[`textadept.editing.auto_pairs`]: api.html#textadept.editing.auto_pairs
[`textadept.editing.auto_enclose`]: api.html#textadept.editing.auto_enclose

#### Navigate Through History

Textadept records buffer positions within views over time and allows for
navigating through that history. Navigate backward or forward via `Alt+,` or
`Alt+.`, respectively, on Windows, Linux, and BSD; `^,` or `^.`, respectively,
on macOS; and `M-,` or `M-.`, respectively, in the terminal version.

#### Goto Line

You can jump to a specific line in the current buffer via `Ctrl+J` on Windows,
Linux, and BSD, `⌘J` on macOS, and `^J` in the terminal version. Enter the line
number to jump to in the prompt, and press `Enter` or click `OK`.

#### Bookmarks

Bookmarks are markers attached to lines of interest. They move in sync with the
lines they were added to as buffer text is inserted and deleted. Bookmarks show
up in the left-hand margin after line numbers. Textadept allows you to bookmark
lines and jump back to them later. The following key bindings apply for
bookmarks:

* Toggle a bookmark on the current line via `Ctrl+F2` on Windows, Linux, and
  BSD, `⌘F2` on macOS, and `F1` in the terminal version.
* Jump to the next bookmarked line via `F2`.
* Jump to the previously bookmarked line via `Shift+F2` on Windows, Linux, and
  BSD, `⇧F2` on macOS, and `F3` in the terminal version.
* Jump to the bookmarked line selected from a list via `Alt+F2` on Windows,
  Linux, and BSD, `⌥F2` on macOS, and `F4` in the terminal version.
* Clear all bookmarks in the current buffer via `Ctrl+Shift+F2` on Windows,
  Linux, and BSD, `⌘⇧F2` on macOS, and `F6` in the terminal version.

#### Macros

Macros allow you to quickly record a series of edits and play them back without
having to write a custom Lua script. The following key bindings apply for
macros:

* Start recording a macro via `F9`.
* Stop recording a macro via `Shift+F9` on Windows, Linux, and BSD, `⇧F9` on
  macOS, and `F10` in the terminal version.
* Play back the most recently recorded macro via `Alt+F9` on Windows, Linux, and
  BSD, `⌥F9` on macOS, and `F12` in the terminal version.

You can use the "Tools > Macros" menu to save the most recently recorded macro
to a file, and to load one for playback on demand.

#### Snippets

Snippets are dynamic text templates that can be inserted into the buffer on
demand. They are composed of any combination of plain text, placeholders for
interactive input, mirrors and transforms for interactive input, and arbitrary
Lua and Shell code. Snippets eliminate the need for typing repetitive code
constructs like class definitions, getters and setters, control structures, API
calls, and more.

![Snippet](images/snippet.png)
&nbsp;&nbsp;&nbsp;&nbsp;
![Snippet Expanded](images/snippet2.png)

A snippet has a trigger word associated with snippet text in the [`snippets`][]
table. Language-specific snippets are in a subtable assigned to their language's
lexer name, and are often supplied by [language][] [modules](#modules). Snippets
may also be the contents of files in a snippet directory, with file names being
the trigger word. The [snippets documentation][] describes snippets and their
contents in more detail.

The following key bindings apply for snippets:

* Insert a snippet from a list of available snippets via `Ctrl+Shift+K` on
  Windows, Linux, and BSD, `⌥⇧⇥` on macOS, and `M-S-K` in the terminal version.
  Typing part of a snippet trigger in the dialog filters the list, with spaces
  being wildcards. The arrow keys move the selection up and down. Pressing
  `Enter`, selecting `OK`, or double-clicking on a snippet inserts it into the
  current buffer. (The terminal requires pressing `Enter`.)
* Show completion candidates for a partially-typed snippet trigger word via
  `Ctrl+K` on Windows, Linux, and BSD, `⌥⇥` on macOS, and `M-K` in the terminal
  version. Continuing to type changes the suggested completion. Use the arrow
  keys to navigate within the list and press `Enter` to insert the rest of the
  trigger word.
* Insert a snippet based on the trigger word behind the caret via `Tab` on
  Windows, Linux, BSD, and in the terminal version, and `⇥` on macOS. You can
  insert another snippet within an active snippet. A previously active snippet
  will pick up where it left off after a nested snippet finishes.
* Navigate to the next placeholder in the current snippet via `Tab` on Windows,
  Linux, BSD, and in the terminal version, and `⇥` on macOS.
* Navigate to the previous placeholder in the current snippet via `Shift+Tab` on
  Windows, Linux, and BSD, `⇧⇥` on macOS, and `S-Tab` in the terminal version.
  If there is no previous placeholder, the current snippet is canceled.
* Cancel the current snippet via `Esc`.

[`snippets`]: api.html#_G.snippets
[language]: api.html#_M
[snippets documentation]: api.html#textadept.snippets

#### Code Folding

Textadept can temporarily hide blocks of code in supported languages. Markers in
the margin to the left of code denote fold points. Clicking on those markers
toggles folding. You can toggle folding for the current block via `Ctrl+*` on
Windows, Linux, and BSD, `⌘*` on macOS, and `M-*` in the terminal version.

![Folding](images/folding.png)

#### Virtual Space

Textadept normally constrains the caret to remain within text lines. Enabling
virtual space allows you to move the caret into the space beyond the ends of
lines. Toggle virtual space via `Ctrl+Alt+Shift+V` on Windows, Linux, and BSD,
and `^⇧V` in macOS. (The terminal version does not have a default key binding
for toggling virtual space.)

#### Key Bindings

Key bindings are simply commands (Lua functions) assigned to key sequences in
the [`keys`][] table. Key sequences are composed of an ordered combination of
modifier keys followed by either the key's inserted character or, if no such
character exists, the string representation of the key according to
[`keys.KEYSYMS`][]. Language-specific keys are in a subtable assigned to their
language's lexer name, and are often supplied by [language][]
[modules](#modules). Key sequences can also be assigned tables of key bindings
to create key chains (e.g. Emacs `C-x` prefix). Key bindings can be grouped into
modes such that while a mode is active, Textadept ignores all key bindings
outside that mode until the mode is unset (e.g. Vim-style modal editing). The
[keys documentation][] describes all of this in more detail.

[`keys`]: api.html#keys
[`keys.KEYSYMS`]: api.html#keys.KEYSYMS
[language]: api.html#_M
[keys documentation]: api.html#keys

--------------------------------------------------------------------------------
### Compile, Run, Build, and Test
--------------------------------------------------------------------------------

Textadept knows most of the commands that compile and/or run code in source
files. It also knows some of the commands that build projects, and you can tell
the editor how to run your project's test suite. Textadept recognizes many of
the warning and error messages emitted by those commands and marks them as they
occur in compile/run/build/test output. Double-clicking on a line with a warning
or error jumps to its source.

The following key bindings apply for compiling and running source files, and
for building projects and running tests:

* Compile the current file via `Ctrl+Shift+R` on Windows, Linux, and BSD, `⌘⇧R`
  on macOS, and `M-^R` in the terminal version.
* Run the current file via `Ctrl+R` on Windows, Linux, and BSD, `⌘R` on macOS,
  and `^R` in the terminal version.
* Set, using an interactive dialog, the command line arguments for the current
  file's compile and run commands via `Ctrl+Shift+A` on Windows, Linux, and BSD,
  and `⌘⇧A` on macOS. (The terminal version does not have a default key binding
  for setting command line arguments.) Enter the command line arguments for each
  command and press `Enter` or click `OK`.
* Build the current project via `Ctrl+Shift+B` on Windows, Linux, and BSD, `⌘⇧B`
  on macOS, and `M-^B` in the terminal version.
* Run tests for the current project via `Ctrl+Shift+T` on Windows, Linux, and
  BSD, `⌘⇧T` on macOS, and `M-^T` in the terminal version.
* Stop the currently running compile, run, build, or test process via
  `Ctrl+Shift+X` on Windows, Linux, and BSD, `⌘⇧X` on macOS, and `M-^X` in the
  terminal version.
* Jump to the source of the next recognized warning or error via `Ctrl+Alt+E` on
  Windows, Linux, and BSD, `^⌘E` on macOS, and `M-X` in the terminal version.
* Jump to the source of the previously recognized warning or error via
  `Ctrl+Alt+Shift+E` on Windows, Linux, and BSD, `^⌘⇧E` on macOS, and `M-S-X` in
  the terminal version.
* Jump to the source of the recognized warning or error on the current line via
  `Enter`.

![Runtime Error](images/runerror.png)

When you execute a compile, run, build, or test command, that command's output
is printed to a temporary buffer in real-time. You can configure Textadept to
print output in the background by setting [`textadept.run.run_in_background`][].
For example, in your *~/.textadept/init.lua*:

    textadept.run.run_in_background = true

You can change or add compile, run, build, and test commands by modifying the
[`textadept.run.compile_commands`][], [`textadept.run.run_commands`][],
[`textadept.run.build_commands`][], and [`textadept.run.test_commands`][]
tables, respectively. You can add Lua patterns that recognize warning and error
output by modifying the [`textadept.run.error_patterns`][] table. For example,
in your *~/.textadept/init.lua*:

    textadept.run.compile_commands.foo = 'foo "%f"'
    textadept.run.run_commands.foo = './"%e"'
    textadept.run.error_patterns.foo = {'^(.-):(%d+): (.+)$'} -- bar.foo:1: oops

    textadept.run.build_commands['/path/to/project'] = 'make -C src -j4'
    textadept.run.test_commands['/path/to/project'] = 'lua tests.lua'

**Tip:** you can set compile and run commands on a per-filename basis, and these
commands can contain arguments so that you do not have to invoke
"Tools > Set Arguments..."

[`textadept.run.run_in_background`]: api.html#textadept.run.run_in_background
[`textadept.run.compile_commands`]: api.html#textadept.run.compile_commands
[`textadept.run.run_commands`]: api.html#textadept.run.run_commands
[`textadept.run.build_commands`]: api.html#textadept.run.build_commands
[`textadept.run.test_commands`]: api.html#textadept.run.test_commands
[`textadept.run.error_patterns`]: api.html#textadept.run.error_patterns

--------------------------------------------------------------------------------
### Modules
--------------------------------------------------------------------------------

Modules are packages of Lua code that provide functionality for Textadept. Most
of the editor's features come from individual modules (see Textadept's *core/*
and *modules/* directories). Textadept can load modules when the application
starts up, or it can load modules on-demand in response to events. Once a module
is loaded, it persists in memory and is never unloaded. Textadept attempts to
load, in order, a given module from the following locations:

1. Your *~/.textadept/modules/* directory.
2. Textadept's *modules/* directory.

**Tip:** placing modules in your user data directory avoids the possibility of
you overwriting them when you update Textadept. These modules also take
precedence over the ones installed with Textadept.

Textadept will only load modules it is explicitly told to load (e.g. from your
*~/.textadept/init.lua*). For example, in your *~/.textadept/init.lua*:

    local ctags = require('ctags')
    ctags.f12 = ctags.goto_tag

    events.connect(events.LEXER_LOADED, function(name)
      if name == 'lua' then require('lua.extras') end
    end)

The only exception to this auto-loading prohibition is modules that have the
same name as a lexer language. These so-called "[language modules][]" will be
automatically loaded when an appropriate source file is opened, or when the
module's associated lexer is loaded for a buffer.

**Note:** lexer language names are typically the names of lexer files in your
*~/.textadept/lexers/* directory and Textadept's *lexers/* directory.

#### Developing Modules

Modules follow the Lua package model: a module is either a single Lua file or
a group of Lua files in a directory that contains an *init.lua* file (which is
the module's entry point). The name of the module is its file name or directory
name, respectively. Here are some basic guidelines for developing modules and
some things to keep in mind:

* Modules should return a table of functions and fields that are defined
  locally, rather than globally. (This is standard Lua practice.) That way, the
  construct `local foo = require('foo')` behaves as expected.
* Modules should not define global variables, as all modules share the same Lua
  state.
* Only [language modules][] should be named after lexer languages.
* Modules must not call any functions that create buffers and views (e.g.
  `ui.print()`, `io.open_file()`, and `buffer.new()`) at file-level scope.
  Buffers and views can only be created within functions assigned to keys,
  associated with menu items, or connected to events.
* Additional documentation on creating language modules can be found in the
  the [language modules][] documentation.

**Tip:** you do not need to have a language module in order to have
language-specific editing features. You can simply put language-specific
features inside an [`events.LEXER_LOADED`][] event handler. For example, in your
*~/.textadept/init.lua*:

    -- Auto-pair and brace-match '<' and '>' only in HTML and XML files.
    events.connect(events.LEXER_LOADED, function(name)
      local is_markup = name == 'html' or name == 'xml'
      textadept.editing.auto_pairs[string.byte('<')] = is_markup and '>'
      textadept.editing.brace_matches[string.byte('<')] = is_markup
      textadept.editing.brace_matches[string.byte('>')] = is_markup
    end)

[language modules]: api.html#_M
[`events.LEXER_LOADED`]: api.html#events.LEXER_LOADED

--------------------------------------------------------------------------------
### Themes
--------------------------------------------------------------------------------

Themes customize Textadept's look and feel. The editor comes with three built-in
themes: "light", "dark", and "term". The default theme for the GUI and terminal
versions is "light" and "term", respectively.

<span style="display: block; clear: right;"></span>

![Light Theme](images/lighttheme.png)
&nbsp;&nbsp;
![Dark Theme](images/darktheme.png)
&nbsp;&nbsp;
![Term Theme](images/termtheme.png)

A theme consists of a single Lua file, and is typically responsible for:

* Defining the [colors][] and [text display settings][] (styles) used in syntax
  highlighting.
* Assigning colors to various UI elements such as the caret, text selections,
  margin markers, and documentation popups.
* Specifying what symbols to use for margin markers and how to display visual
  elements like the brace match indicator and snippet placeholders.

[colors]: api.html#lexer.colors
[text display settings]: api.html#lexer.styles

Textadept attempts to load, in order, a given theme from the following
locations:

1. Your *~/.textadept/themes/* directory.
2. Textadept's *themes/* directory.

**Tip:** placing themes in your user data directory avoids the possibility of
you overwriting them when you update Textadept. These themes also take
precedence over the ones installed with Textadept.

You can set Textadept's theme using [`view.set_theme()`][]. You can also tweak a
theme's styles on a per-language basis. For example, in your
*~/.textadept/init.lua*:

    if not CURSES then
      view:set_theme('light', {font = 'DejaVu Sans Mono', size = 12})
    end

    -- Color Java functions black instead of the default orange.
    events.connect(events.LEXER_LOADED, function(name)
      if name ~= 'java' then return end
      local default_fore = view.style_fore[view.STYLE_DEFAULT]
      view.style_fore[buffer:style_of_name('function')] = default_fore
    end)

**Tip:** you can experiment with themes without having to restart Textadept by
using the [`reset()`][] command in the [Lua Command Entry](#lua-command-entry).
Once you make changes to either your *~/.textadept/init.lua* or theme file,
issuing the `reset` command will reload your changes.

[`view.set_theme()`]: api.html#view.set_theme
[`reset()`]: api.html#reset

The widgets in the GUI version of Textadept cannot be themed using Lua theme
files. Instead, you must use [GTK Resource Files][], which are part of the GUI
toolkit Textadept uses.

**Note:** Textadept's pre-built binaries are built for and linked against GTK 2,
not GTK 3.

[GTK Resource Files]: https://developer.gnome.org/gtk3/stable/gtk3-Resource-Files.html

--------------------------------------------------------------------------------
### Scripting
--------------------------------------------------------------------------------

Nearly every aspect of Textadept can be scripted, or controlled, using Lua.
Textadept contains its own internal copy of [Lua 5.3][], which is largely
unmodified compared to the official Lua release. The main difference is that
Textadept's Lua does not have any compatibility options turned on for previous
versions of Lua.

Being an event-driven application, Textadept simply responds to input like key
presses, mouse clicks, and state changes by running Lua code (more specifically,
executing Lua functions). For example, when you press a key, Textadept emits an
`events.KEYPRESS` event, which its *core/keys.lua* is listening for. When a
sequence like `Ctrl+O` on Windows, Linux, and BSD is recognized, *core/keys.lua*
looks up which Lua function is assigned to the `keys['ctrl+o']` key. By default,
it is `io.open_file()`, so that function is executed and the user is prompted
for a file to open. You could bind a different function to that key and
Textadept will duly execute it. Similarly, when the editor opens a file via
`io.open_file()`, that function emits a `events.FILE_OPENED` event, which
*modules/textadept/file_types.lua* is listening for. When a Lua file is opened,
*modules/textadept/file_types.lua* designates the "lua" lexer to perform syntax
highlighting on that file and also loads the Lua language module if it has not
already been loaded. You could also listen for `events.FILE_OPENED` in your
*~/.textadept/init.lua* and perform your own action, such as loading some
project-specific tools for editing that file.

Your *~/.textadept/init.lua* is the entry point to scripting Textadept. In this
file you can set up custom key bindings, menu items, and event handlers that
will perform custom actions. Here are some ideas:

* Define custom key bindings and menu items that manipulate buffer contents via
  the extensive [`buffer`][] API.
* Extend Textadept's File menu with a menu item that prompts for a commit
  message using an [interactive dialog][], and then invokes a shell command that
  commits the current file to version control using the provided message.
* Listen for the `events.FILE_SAVED` [event][] and [spawn][] an asynchronous
  process that runs a syntax checker, linter, or formatter on a source file when
  it is saved.
* Start searches with the word under the caret by substituting the
  "Search > Find" menu item and key binding functions with a custom function
  that pre-populates `ui.find.find_entry_text` before calling `ui.find.focus()`
  to show the find & replace pane.
* Auto-save files as you switch between buffers by listening for the
  `events.BUFFER_BEFORE_SWITCH` event and calling `buffer:save()` for buffers
  that have a `buffer.filename`. In the GUI version, you can even auto-save on
  a timer via `timeout()`.
* Overload Textadept's find & replace capabilities to use Lua patterns instead
  of regex by reacting to `events.FIND` and `events.REPLACE` before Textadept
  can, and then determining whether or not the editor's default routines should
  handle those events.

Textadept's [Lua API][] is extensively documented and serves as the ultimate
resource when it comes to scripting the editor. The claim "Textadept gives you
complete control over nearly the entire application using Lua" is not an
exaggeration!

If you are looking for a more structured scripting resource,
[Textadept Quick Reference][] contains a wealth of knowledge on how to script
and configure Textadept. It groups the editor's rich API into a series of tasks
in a convenient and easy-to-use manner.

[Lua 5.3]: https://www.lua.org/manual/5.3
[`buffer`]: api.html#buffer
[interactive dialog]: api.html#ui.dialogs
[event]: api.html#events
[spawn]: api.html#os.spawn
[Lua API]: api.html
[Textadept Quick Reference]: book.html

#### Generate Autocompletion and Documentation Files

You can generate for use with Textadept
[autocompletion and documentation](#autocompletion-and-documentation) files for
your Lua modules. Simply run [LuaDoc][] with Textadept's *modules/lua/tadoc.lua*
doclet. For example:

    luadoc -d [output_path] --doclet _HOME/modules/lua/tadoc.lua [module(s)]

where `_HOME` is the path where you installed Textadept and `output_path` is an
arbitrary path to write the generated *tags* and *api* files to. You can then
have Textadept load and use those autocompletion and documentation files when
editing Lua code. For example, in your *~/.textadept/init.lua*:

    local loaded_tags = false
    events.connect(events.LEXER_LOADED, function(name)
      if name ~= 'lua' or loaded_tags then return
      _M.lua.tags[#_M.lua.tags + 1] = '/path/to/tags'
      loaded_tags = true
    end)
    table.insert(textadept.editing.api_files.lua, '/path/to/api')

[LuaDoc]: https://keplerproject.github.com/luadoc

--------------------------------------------------------------------------------
### Compiling
--------------------------------------------------------------------------------

Textadept is a bit unusual in that building it is only supported on Linux and
BSD, or within a [Docker][] [image][]. The application is cross-compiled for
Windows and macOS from Linux. While it is certainly possible to compile
Textadept natively on those platforms, it is simply not supported in any
official capacity.

#### Requirements

The requirements for compiling Textadept on Linux or BSD should be readily
available from a package manager. The requirements for cross-compiling Textadept
for Windows from Linux should also be easily obtainable.

Linux requirements:

* [GNU C compiler][] (*gcc*) 7.1+ (circa mid-2017)
* [GNU Make][] (*make*)
* [GTK][] 2.24+ development libraries for the GUI version
* [ncurses][](w) development libraries (wide character support) for the terminal
  version
* _**OR**_
* [Docker][]

**Note:** on Ubuntu for example, these dependencies would be provided by the
`build-essential`, `libgtk2.0-dev`, `libncurses5-dev`, `libncursesw5-dev`, and
`docker.io` packages.

BSD requirements:

* [GNU C compiler][] (*gcc*) 7.1+ or [Clang][] 4.0+
* [GNU Make][] (*gmake*)
* [pkg-config][]
* [libiconv][]
* [GTK][] 2.24+ development libraries for the GUI version
* [ncurses][](w) development libraries (wide character support) for the terminal
  version

Windows cross-compiling requirements:

* [mingw-w64][] 5.0+ with GCC 7.1+
* _**OR**_
* [Docker][]

**Note:** on Ubuntu for example, the compiler dependency would be provided by
the `gcc-mingw-w64` and `g++-mingw-w64` packages.

macOS cross-compiling requirements:

* [OSX cross toolchain][] with [Clang][] 4.0+
* _**OR**_
* [Docker][]

**Note:** Textadept's *src/Dockerfile* contains an example of how to build an
OSX cross toolchain.

[Docker]: https://www.docker.com
[image]: https://hub.docker.com/repository/docker/textadept/build
[GNU C compiler]: https://gcc.gnu.org
[GNU Make]: https://www.gnu.org/software/make
[Clang]: https://clang.llvm.org
[pkg-config]: https://www.freedesktop.org/wiki/Software/pkg-config
[libiconv]: https://www.gnu.org/software/libiconv
[GTK]: https://www.gtk.org/download/linux.php
[ncurses]: https://invisible-island.net/ncurses/#download_ncurses
[mingw-w64]: http://mingw-w64.org
[OSX cross toolchain]: https://github.com/tpoechtrager/osxcross

#### Compiling

Textadept is built from its *src/* directory and binaries are placed in the
application's root directory. The general procedure is to have Textadept build
its dependencies first, and then its binaries. Textadept is self-contained,
meaning you do not have to install it; it can run from its current location.

The following table provides a brief summary of `make` rules for building
Textadept on Linux and BSD. (On BSD, substitute `make` with `gmake`.)

Command              |Description
---------------------|-----------
`make deps`          |Downloads and builds all of Textadept's core dependencies
`make deps NIGHTLY=1`|Optionally downloads and builds bleeding-edge dependencies
`make`               |Builds Textadept, provided all dependencies are in place
`make GTK3=1`        |Builds Textadept using GTK 3.x
`make DEBUG=1`       |Optionally builds Textadept with debug symbols
`make install`       |Optionally installs Textadept (to */usr/local* by default)
`make curses`        |Builds the terminal version of Textadept
`make curses install`|Optionally installs the terminal version of Textadept
`make uninstall`     |Uninstalls Textadept (from */usr/local* by default)
`make clean`         |Deletes all compiled files, leaving only source files
`make clean-deps`    |Deletes all unpacked dependencies, leaving only downloads
`make win32-deps`    |Downloads and builds Textadept's Windows dependencies
`make win32`         |Cross-compiles Textadept for Windows
`make win32-curses`  |Cross-compiles the terminal version for Windows
`make osx-deps`      |Downloads and builds Textadept's macOS dependencies
`make osx`           |Cross-compiles Textadept for macOS
`make osx-curses`    |Cross-compiles the terminal version for macOS
`make osx-app`       |Builds *Textadept.app*

If you want to install Textadept into a non-standard location, you can specify
that location using the `DESTDIR` variable. For example:

    make install DESTDIR=/prefix/to/install/to

**Linux and BSD note:** if any of Textadept's dependencies are installed under a
prefix that your compiler flags do not include by default (e.g. */usr/local/*),
you will have to run something like:

    make CFLAGS="-I/usr/local/include" \
      CXXFLAGS="-I/usr/local/include -L/usr/local/lib"

Also, if you want to compile with Clang, you will have to run something like:

    make CC=cc CXX=c++

##### Compiling using Docker

You can use [Docker][] to build Textadept for Windows, macOS, or Linux. The
[image][] required to do so is about 2.5GB in size. For example:

    localhost$ docker pull ghcr.io/orbitalquark/textadept-build:v1.0
    localhost$ docker run -t -i -v /path/to/textadept:/ta -w /ta/src \
      ghcr.io/orbitalquark/textadept-build:v1.0
    container# make deps
    container# make
    container# exit

If you prefer to build your own Docker image instead of pulling one, you can
run `docker build .` from Textadept's *src/* directory, which contains the
relevant *Dockerfile*.

You can issue within the container any of the build commands given in
the previous table, though the install commands are meaningless.

**Linux note:** if, when running one of the Linux binaries produced, you get an
error like `/<path>/libstdc++.so.6: version 'GLIBCXX_<version>' not found`, then
try compiling with the following flags:

    container# make CXXFLAGS="-0s -std=c++17 -static-libstdc++"

If you still get an error, this time like
`/<path>/libc.so.6: version 'GLIBC_<version>' not found`, then you will have to
compile Textadept manually without Docker.

[Docker]: https://www.docker.com
[image]: https://github.com/users/orbitalquark/packages/container/textadept-build

--------------------------------------------------------------------------------
### Appendix
--------------------------------------------------------------------------------

#### Regex and Lua Pattern Syntax

The following table outlines Regex and Lua Pattern syntax:

Regex       |Lua      |Meaning
------------|---------|-------
.           |.        |Matches any character
[[:alpha:]] |%a       |Matches any letter
\d          |%d       |Matches any digit
[[:lower:]] |%l       |Matches any lower case character
[[:punct:]] |%p       |Matches any punctuation character
\s          |%s       |Matches any space character
[[:upper:]] |%u       |Matches any upper case character
\w          |%w       |Matches any alphanumeric character (Regex includes '_')
[[:xdigit:]]|%x       |Matches any hexadecimal digit
[*set*]     |[*set*]  |Matches any character in *set*, including ranges like A-Z
[^*set*]    |[^*set*] |Matches the complement of *set*
\*          |\*       |Matches the previous item (Regex) or class (Lua) 0+ times
\+          |+        |Matches the previous item or class 1+ times
\*?         |-        |Matches the previous item or class 0+ times, non-greedily
\+?         |         |Matches the previous item 1+ times, non-greedily
?           |?        |Matches the previous item or class once or not at all
{*m*,*n*}   |         |Matches the previous item between *m* and *n* times
{*m*,}      |         |Matches the previous item at least *m* times
{*m*}       |         |Matches the previous item exactly *m* times
\|          |         |Matches either the previous item or the next item
&nbsp;      |%b*xy*   |Matches a balanced string bounded by *x* and *y*
&nbsp;      |%f[*set*]|Matches a position between characters not in and in *set*
\\<         |         |Matches the beginning of a word
\\>         |         |Matches the end of a word
\b          |         |Matches a word boundary
^           |^        |Matches the beginning of a line unless inside a set
$           |$        |Matches the end of a line unless inside a set
(           |(        |The beginning of a captured matching region
)           |)        |The end of a captured matching region
(?:*...*)   |         |Consider matched "*...*" as a single, uncaptured item
\\*n*       |%*n*     |The *n*th captured matching region's text<sup>a</sup>
\\*x*       |%*x*     |Non-alphanumeric character *x*, ignoring special meaning

<sup>a</sup>In replacement text, "\0" (Regex) or "%0" (Lua) represents all
matched text.

Textadept's regular expressions are based on the C++11 standard for ECMAScript.
There are a number of references for this syntax on the internet, including:

* [ECMAScript syntax C++ reference](https://www.cplusplus.com/reference/regex/ECMAScript/)
* [Modified ECMAScript regular expression grammar](https://en.cppreference.com/w/cpp/regex/ecmascript)
* [Regular Expressions (C++)](https://docs.microsoft.com/en-us/cpp/standard-library/regular-expressions-cpp)

More information on Lua patterns can be found in the
[Lua 5.3 Reference Manual](https://www.lua.org/manual/5.3/manual.html#6.4.1).

#### Terminal Version Compatibility

Textadept's terminal version requires a font with good glyph support (like
DejaVu Sans Mono or Liberation Mono), and lacks some GUI features due to the
terminal's constraints:

* No alpha values or transparency.
* No images in autocompletion lists. Instead, autocompletion lists show the
  first character in the string passed to [`buffer.register_image()`][].
* No buffered or two-phase drawing.
* Carets cannot have a period, line style, or width.
* No drag and drop.
* Edge lines may be obscured by text.
* No extra line ascent or descent.
* No fold lines above and below lines.
* No hotspot underlines on mouse hover.
* No indicators other than `INDIC_ROUNDBOX` and `INDIC_STRAIGHTBOX`, although
  neither has translucent drawing and `INDIC_ROUNDBOX` does not have rounded
  corners.
* Some complex marker symbols are not drawn properly or at all.
* No mouse cursor types.
* Only up to 16 colors recognized, regardless of how many colors the terminal
  supports. Unrecognized colors default to white.
* Not all key sequences are recognized properly.
* No style settings like font name, font size, or italics.
* No X selection, primary or secondary, integration with the clipboard.
* No zoom.
* When using the mouse in the Windows console, Shift+Double-click extends
  selections and quadruple-clicking inside a selection collapses it.

[`buffer.register_image()`]: api.html#buffer.register_image

#### Directory Structure

Textadept's directory structure is organized as follows:

* *core/*: Contains Textadept's core Lua modules. These modules are essential
  for the application to run. They provide Textadept's Lua to C interface, event
  framework, file interactions, and localization.
* *lexers/*: Houses the lexer modules that analyze source code for syntax
  highlighting.
* *modules/*: Contains modules for editing text and source code, as well as
  language modules.
* *themes/*: Contains built-in themes that customize the look and feel of
  Textadept.
* *etc/*, *lib/*, and *share/*: GTK support directories and only appear in the
  Windows and macOS packages.

#### Technologies

Textadept is composed of the following technologies:

* [GTK][]: cross-platform GUI toolkit
* [ncurses][]: terminal UI library for Linux, macOS, and BSD
* [pdcurses][]: terminal UI library for Windows
* [gtDialog][]: interactive GUI and terminal UI dialog library
* [cdk][]: terminal UI widget toolkit
* [libtermkey][]: terminal keyboard entry handling library
* [Scintilla][]: core text editing component
* [Lexilla][]: core syntax highlighting library for Scintilla
* [Scinterm][]: curses (terminal) platform for Scintilla
* [Scintillua][]: syntax highlighting for Scintilla using Lua lexers
* [Lua][]: core scripting language
* [LPeg][]: Lua pattern matching library for syntax highlighting
* [LuaFileSystem][]: Lua library for accessing the host filesystem

[GTK]: https://www.gtk.org
[Scintilla]: https://scintilla.org
[Lexilla]: https://scintilla.org/Lexilla.html
[Scinterm]: https://orbitalquark.github.io/scinterm
[Scintillua]: https://orbitalquark.github.io/scintillua
[Lua]: https://www.lua.org
[LPeg]: http://www.inf.puc-rio.br/~roberto/lpeg/lpeg.html
[LuaFileSystem]: https://keplerproject.github.io/luafilesystem
[gtDialog]: https://orbitalquark.github.io/gtdialog
[ncurses]: https://invisible-island.net/ncurses
[pdcurses]: http://pdcurses.sourceforge.net
[cdk]: https://invisible-island.net/cdk
[libtermkey]: http://www.leonerd.org.uk/code/libtermkey

#### Migrating from Textadept 10 to 11

##### API Changes

Old API                    |Change  |New API
---------------------------|:------:|-------
**buffer**                 |        |
set_theme()                |Renamed |[view:set_theme()][]
style_name[n]              |Replaced|[name_of_style][](n)
CASEINSENSITIVEBEHAVIOUR\_*|Renamed |CASEINSENSITIVEBEHAVIOR\_*
INDIC\_GRADIENTCENTRE      |Renamed |INDIC\_GRADIENTCENTER
MARGIN\_COLOUR             |Renamed |MARGIN\_COLOR
auto\_c\_case_insensitive\_behaviour|Renamed|auto\_c\_case\_insensitive\_behavior
colourise                  |Renamed |colorize
edge\_colour               |Renamed |edge\_color
set\_fold\_margin\_\*colour|Renamed |set\_fold\_margin\_\*color
vertical\_centre\_caret    |Renamed |vertical\_center\_caret
**events**                 |        |
AUTO\_C\_CANCELLED         |Renamed |AUTO\_C\_CANCELED
N/A                        |Added   |[COMMAND_TEXT_CHANGED][]
N/A                        |Added   |[FILE_BEFORE_RELOAD][]
N/A                        |Added   |[FILE_AFTER_RELOAD][]
N/A                        |Added   |[FIND_RESULT_FOUND][]
N/A                        |Added   |[FIND_TEXT_CHANGED][]
N/A                        |Added   |[SESSION_SAVE][]
N/A                        |Added   |[SESSION_LOAD][]
N/A                        |Added   |[UNFOCUS][]
**io**                     |        |
reload_file()              |Renamed |[buffer:reload()][]
save_file()                |Renamed |[buffer:save()][]
save_file_as()             |Renamed |[buffer:save_as()][]
close_buffer()             |Renamed |[buffer:close()][]
**keys**                   |        |
MODE                       |Renamed |[mode][]
**lexer**                  |        |
N/A                        |Added   |[to_eol()][]
delimited\_range()         |Replaced|[range()][]
nested\_pair()             |Replaced|[range()][]
fold\_line\_comments()     |Replaced|[fold_consecutive_lines()][]<sup>a</sup>
N/A                        |Added   |[number][]
N/A                        |Added   |[colors][]
N/A                        |Added   |[styles][]
N/A                        |Added   |[folding][] and other fold\* properties
**lfs**                    |        |
dir\_foreach()             |Replaced|for filename in [lfs.walk()][] do ... end
**textadept.bookmarks**    |        |
toggle(line, on)           |Changed |[toggle()][]
**textadept.editing**      |        |
block\_comment()           |Renamed |[toggle_comment()][]
highlight_word()           |Replaced|[highlight_words][]
**textadept.file_types**   |        |
lexers                     |Removed |N/A<sup>b</sup>
**textadept.find**         |        |
find\_incremental()        |Replaced|[incremental][]<sup>c</sup>
find\_incremental\_keys    |Removed |
N/A                        |Added   |[highlight_all_matches][]
**textadept.history**      |Added   |[textadept.history][]
**textadept.run**          |        |
N/A                        |Added   |[set_arguments][]
**textadept.snippets**     |        |
\_insert()                 |Renamed |[insert()][]
\_previous()               |Renamed |[previous()][]
\_cancel_current()         |Renamed |[cancel_current()][]
\_select()                 |Renamed |[select()][]
\_paths                    |Renamed |[paths][]
**ui**                     |        |
bufstatusbar\_text         |Renamed |[buffer_statusbar_text][]
**ui.command_entry**       |        |
N/A                        |Added   |[active][]
N/A                        |Added   |[append_history][]
**ui.dialogs**             |        |
N/A                        |Added   |[progressbar()][]
**ui.find**                |        |
find\_in\_files\_timeout   |Removed |N/A
N/A                        |Added   |[active][]
**view**                   |        |
N/A                        |Added   |_buffer functions and fields_<sup>d</sup>

<sup>a</sup>Returns prefix and function, instead of just function.<br/>
<sup>b</sup>Use `for name in buffer:private_lexer_call(_SCINTILLA.functions.property_names[1]):gmatch('[^\n]+') do ... end`.<br/>
<sup>c</sup>Use `textadept.menu.menubar[_L['Search']][_L['Find Incremental']][2]`.<br/>
<sup>d</sup>Most buffer functions and fields are available in views now. See
section below.

[view:set_theme()]: api.html#view.set_theme
[name_of_style]: api.html#buffer.name_of_style
[COMMAND_TEXT_CHANGED]: api.html#events.COMMAND_TEXT_CHANGED
[FILE_BEFORE_RELOAD]: api.html#events.FILE_BEFORE_RELOAD
[FILE_AFTER_RELOAD]: api.html#events.FILE_AFTER_RELOAD
[FIND_RESULT_FOUND]: api.html#events.FIND_RESULT_FOUND
[FIND_TEXT_CHANGED]: api.html#events.FIND_TEXT_CHANGED
[SESSION_SAVE]: api.html#events.SESSION_SAVE
[SESSION_LOAD]: api.html#events.SESSION_LOAD
[UNFOCUS]: api.html#events.UNFOCUS
[buffer:reload()]: api.html#buffer.reload
[buffer:save()]: api.html#buffer.save
[buffer:save_as()]: api.html#buffer.save_as
[buffer:close()]: api.html#buffer.close
[mode]: api.html#keys.mode
[to_eol()]: api.html#lexer.to_eol
[range()]: api.html#lexer.range
[fold_consecutive_lines()]: api.html#lexer.fold_consecutive_lines
[number]: api.html#lexer.number
[colors]: api.html#lexer.colors
[styles]: api.html#lexer.styles
[folding]: api.html#lexer.folding
[lfs.walk()]: api.html#lfs.walk
[toggle()]: api.html#textadept.bookmarks.toggle
[toggle_comment()]: api.html#textadept.editing.toggle_comment
[highlight_words]: api.html#textadept.editing.highlight_words
[incremental]: api.html#ui.find.incremental
[highlight_all_matches]: api.html#ui.find.highlight_all_matches
[textadept.history]: api.html#textadept.history
[set_arguments]: api.html#textadept.run.set_arguments
[insert()]: api.html#textadept.snippets.insert
[previous()]: api.html#textadept.snippets.previous
[cancel_current()]: api.html#textadept.snippets.cancel_current
[select()]: api.html#textadept.snippets.select
[paths]: api.html#textadept.snippets.paths
[buffer_statusbar_text]: api.html#ui.buffer_statusbar_text
[active]: api.html#ui.command_entry.active
[append_history]: api.html#ui.command_entry.append_history
[progressbar()]: api.html#ui.dialogs.progressbar
[active]: api.html#ui.find.active

##### Buffer Indexing Changes

All buffer positions, lines, and countable entities now start from `1` instead
of `0`. For example, `buffer:get_line(1)` now returns the contents of the first
line instead of `buffer:get_line(0)`, and marker and indicator numbers now count
from 1 instead of 0.

While this change may seem daunting for migrating user scripts, in practice it
is not, since most usage is internal, and an offset of 1 or 0 does not matter.
In migrating Textadept's internals, the following changes were made:

* Themes that loop through marker numbers will need to be updated from something
  like `for i = 25, 31 do ... end` to either `for i = 26, 32 do ... end` or
  `for i = buffer.MARKNUM_FOLDEREND, buffer.MARKNUM_FOLDEROPEN do ... end`.
* Most references of `buffer.length` will need to be changed to
  `buffer.length + 1`. For example, something like
  `buffer:goto_pos(buffer.length)` needs to be
  `buffer:goto_pos(buffer.length + 1)`. The exceptions are when `buffer.length`
  is not used as a position, as in
  `buffer:indicator_clear_range(1, buffer.length)`, which is still valid.
* Any `buffer` function calls and property indexing with bare numbers should be
  changed to calls or indexes with those numbers plus 1. For example,
  `buffer:contracted_fold_next(0)` changes to `buffer:contracted_fold_next(1)`,
  and `buffer.margin_n_width[1] = ...` changes to
  `buffer.margin_n_width[2] = ...`.
* Any looping through lines, margins, and selections via
  `for i = 0, buffer.{line_count,margins,selections} - 1 do ... end` needs to be
  `for i = 1, buffer.{line_count,margins,selections} do ... end`.
* Similarly, any language modules that loop back through lines (e.g. to
  determine types for autocompletion) via
  `for i = current_line, 0, -1 do ... end` needs to be
  `for i = current_line, 1, -1 do ... end`.
* Marker or indicator masks are produced by subtracting 1 from marker or
  indicator numbers. For example, `1 << textadept.bookmarks.MARK_BOOKMARK`
  changes to `1 << textadept.bookmarks.MARK_BOOKMARK - 1`.
* Logic that depends on the return value of `buffer:get_cur_line()` may need to
  be changed. For example, any subsequent references to `pos` after
  `local line, pos = buffer:get_cur_line()` like `if line:sub(1, pos) ... end`
  need to be changed to `if line:sub(1, pos - 1) ... end`.

I found it helpful to quickly scan source files for syntax-highlighted numbers
and then seeing if those numbers needed to be changed. Searching for "- 1",
"+ 1", "buffer.length", etc. was also helpful.

##### View API Additions and Buffer API Changes

Textadept's [buffer][] API is largely based on the [Scintilla API][], which does
not distinguish between buffer- and view-specific functionality. Textadept 11
now attempts to separate this functionality, but only superficially. Buffers and
views may be used interchangeably for the most part, but the [buffer][] and
[view][] API provides _guidance_ (not hard requirements) on which functions and
fields are more appropriate for their respective objects. _User scripts do not
need to be updated and will continue to function normally_. The following "Find"
regex can be used to help convert `buffer.*` functionality to `view.*`:

<pre style="word-wrap: break-word;">
<code>(\w+)([.:])\b(additional_caret_fore|additional_carets_blink|additional_carets_visible|additional_sel_alpha|additional_sel_back|additional_sel_fore|all_lines_visible|annotation_visible|auto_c_max_height|auto_c_max_width|call_tip_fore_hlt|call_tip_pos_start|call_tip_position|call_tip_use_style|caret_fore|caret_line_back|caret_line_back_alpha|caret_line_frame|caret_line_visible|caret_line_visible_always|caret_period|caret_style|caret_width|cursor|edge_colour|edge_column|edge_mode|end_at_last_line|extra_ascent|extra_descent|first_visible_line|fold_display_text_style|fold_expanded|fold_flags|h_scroll_bar|highlight_guide|idle_styling|indentation_guides|indic_alpha|indic_fore|indic_hover_fore|indic_hover_style|indic_outline_alpha|indic_style|indic_under|line_visible|lines_on_screen|margins|margin_back_n|margin_cursor_n|margin_left|margin_mask_n|margin_options|margin_right|margin_sensitive_n|margin_type_n|margin_width_n|marker_alpha|marker_back|marker_back_selected|marker_fore|mouse_dwell_time|mouse_selection_rectangular_switch|property|property_expanded|property_int|rectangular_selection_modifier|representation|rgba_image_height|rgba_image_scale|rgba_image_width|scroll_width|scroll_width_tracking|sel_alpha|sel_eol_filled|size|style_back|style_bold|style_case|style_changeable|style_eol_filled|style_font|style_fore|style_italic|style_size|style_underline|style_visible|tab_draw_mode|v_scroll_bar|view_eol|view_ws|whitespace_size|wrap_indent_mode|wrap_mode|wrap_start_indent|wrap_visual_flags|wrap_visual_flags_location|x_offset|zoom|ANNOTATION_BOXED|ANNOTATION_HIDDEN|ANNOTATION_STANDARD|ANNOTATION_INDENTED|CARETSTYLE_BLOCK|CARETSTYLE_INVISIBLE|CARETSTYLE_LINE|CARET_EVEN|CARET_JUMPS|CARET_SLOP|CARET_STRICT|EDGE_BACKGROUND|EDGE_LINE|EDGE_MULTILINE|EDGE_NONE|FOLDACTION_CONTRACT|FOLDACTION_EXPAND|FOLDACTION_TOGGLE|FOLDDISPLAYTEXT_HIDDEN|FOLDDISPLAYTEXT_STANDARD|FOLDDISPLAYTEXT_BOXED|INDIC_BOX|INDIC_COMPOSITIONTHICK|INDIC_COMPOSITIONTHIN|INDIC_DASH|INDIC_DIAGONAL|INDIC_DOTBOX|INDIC_DOTS|INDIC_FULLBOX|INDIC_GRADIENT|INDIC_GRADIENTCENTRE|INDIC_HIDDEN|INDIC_PLAIN|INDIC_POINT|INDIC_POINTCHARACTER|INDIC_ROUNDBOX|INDIC_SQUIGGLE|INDIC_SQUIGGLELOW|INDIC_SQUIGGLEPIXMAP|INDIC_STRAIGHTBOX|INDIC_STRIKE|INDIC_TEXTFORE|INDIC_TT|MOD_ALT|MOD_CTRL|MOD_META|MOD_SHIFT|MOD_SUPER|MOUSE_DRAG|MOUSE_PRESS|MOUSE_RELEASE|WS_INVISIBLE|WS_VISIBLEAFTERINDENT|WS_VISIBLEALWAYS|WS_VISIBLEONLYININDENT|ALPHA_NOALPHA|ALPHA_OPAQUE|ALPHA_TRANSPARENT|CASE_CAMEL|CASE_LOWER|CASE_MIXED|CASE_UPPER|CURSORARROW|CURSORNORMAL|CURSORREVERSEARROW|CURSORWAIT|FOLDFLAG_LEVELNUMBERS|FOLDFLAG_LINEAFTER_CONTRACTED|FOLDFLAG_LINEAFTER_EXPANDED|FOLDFLAG_LINEBEFORE_CONTRACTED|FOLDFLAG_LINEBEFORE_EXPANDED|FOLDFLAG_LINESTATE|IV_LOOKBOTH|IV_LOOKFORWARD|IV_NONE|IV_REAL|MARGINOPTION_NONE|MARGINOPTION_SUBLINESELECT|MARGIN_BACK|MARGIN_COLOUR|MARGIN_FORE|MARGIN_NUMBER|MARGIN_RTEXT|MARGIN_SYMBOL|MARGIN_TEXT|MARK_ARROW|MARK_ARROWDOWN|MARK_ARROWS|MARK_BACKGROUND|MARK_BOOKMARK|MARK_BOXMINUS|MARK_BOXMINUSCONNECTED|MARK_BOXPLUS|MARK_BOXPLUSCONNECTED|MARK_CHARACTER|MARK_CIRCLE|MARK_CIRCLEMINUS|MARK_CIRCLEMINUSCONNECTED|MARK_CIRCLEPLUS|MARK_CIRCLEPLUSCONNECTED|MARK_DOTDOTDOT|MARK_EMPTY|MARK_FULLRECT|MARK_LCORNER|MARK_LCORNERCURVE|MARK_LEFTRECT|MARK_MINUS|MARK_PIXMAP|MARK_PLUS|MARK_RGBAIMAGE|MARK_ROUNDRECT|MARK_SHORTARROW|MARK_SMALLRECT|MARK_TCORNER|MARK_TCORNERCURVE|MARK_UNDERLINE|MARK_VERTICALBOOKMARK|MARK_VLINE|MASK_FOLDERS|TD_LONGARROW|TD_STRIKEOUT|TIME_FOREVER|WRAPINDENT_DEEPINDENT|WRAPINDENT_FIXED|WRAPINDENT_INDENT|WRAPINDENT_SAME|WRAPVISUALFLAGLOC_DEFAULT|WRAPVISUALFLAGLOC_END_BY_TEXT|WRAPVISUALFLAGLOC_START_BY_TEXT|WRAPVISUALFLAG_END|WRAPVISUALFLAG_MARGIN|WRAPVISUALFLAG_NONE|WRAPVISUALFLAG_START|WRAP_CHAR|WRAP_NONE|WRAP_WHITESPACE|WRAP_WORD|STYLE_BRACEBAD|STYLE_BRACELIGHT|STYLE_CALLTIP|STYLE_CONTROLCHAR|STYLE_DEFAULT|STYLE_FOLDDISPLAYTEXT|STYLE_INDENTGUIDE|STYLE_LINENUMBER|STYLE_MAX|UPDATE_H_SCROLL|UPDATE_V_SCROLL|VISIBLE_SLOP|VISIBLE_STRICT|brace_bad_light|brace_bad_light_indicator|brace_highlight|brace_highlight_indicator|call_tip_active|call_tip_cancel|call_tip_pos_start|call_tip_set_hlt|call_tip_show|clear_registered_images|clear_representation|contracted_fold_next|doc_line_from_visible|ensure_visible|ensure_visible_enforce_policy|fold_all|fold_children|fold_line|get_default_fold_display_text|hide_lines|line_scroll|line_scroll_down|line_scroll_up|marker_define|marker_define_pixmap|marker_define_rgba_image|marker_enable_highlight|marker_symbol_defined|multi_edge_add_line|multi_edge_clear_all|register_image|register_rgba_image|scroll_caret|scroll_to_end|scroll_to_start|scroll_range|set_default_fold_display_text|set_fold_margin_colour|set_fold_margin_hi_colour|set_sel_back|set_sel_fore|set_visible_policy|set_whitespace_back|set_whitespace_fore|set_x_caret_policy|set_y_caret_policy|show_lines|style_clear_all|style_reset_default|text_height|text_width|toggle_fold|toggle_fold_show_text|vertical_centre_caret|visible_from_doc_line|wrap_count|zoom_in|zoom_out|split|unsplit|goto_buffer)\b</code>
</pre>

"Replace" with

    view\2\3

It is not recommended to blindly "Replace All". Each change should be manually
confirmed.

[buffer]: api.html#buffer
[Scintilla API]: https://scintilla.org/ScintillaDoc.html
[Scintilla]: https://scintilla.org
[view]: api.html#view

##### Theme and Lexer Changes

Themes and lexers have a new, optional API for defining and using colors and
styles. Previously, all definitions and access to colors and styles was
accomplished through `buffer.property` and `buffer.property_int`. Now it can be
done via the `lexer.colors` and `lexer.styles` variables. For example:

    -- Textadept 10
    local property, property_int = buffer.property, buffer.property_int
    property['color.blue'] = 0xFF0000
    property['style.keyword'] = 'fore:$(color.blue),bold'
    buffer.edge_colour = property_int['color.grey']

    -- Textadept 11
    local colors, styles = lexer.colors, lexer.styles
    colors.blue = 0xFF0000
    styles.keyword = {fore = colors.blue, bold = true}
    view.edge_color = colors.grey

Any additional settings passed `view:set_theme()` are available as global
variables in the theme. Textadept's themes make use of `font` and `size` (the
latter of which used to be `fontsize`) for easily configuring font and size
per-user.

Lexers can also utilize these new features. For example:

    -- Textadept 10
    lex:add_rule('custom_rule', token('custom', P('word')))
    lex:add_style('custom', lexer.STYLE_KEYWORD .. 'italic')

    -- Textadept 11
    lex:add_rule('custom_rule', token('custom', P('word')))
    lex:add_style('custom', lexer.styles.keyword .. {italic = true})

Note that these features are optional. Themes and lexers setting property
strings is still supported.

##### Localization Changes

GUI mnemonics in localization keys have been removed. For example, `_L['_New']`
should be changed to `_L['New']`. Mnemonics can still be used in localization
values; it's just the keys that have changed. See Textadept's *core/locale.conf*
for examples.

##### Key Bindings Changes

Key sequence modifiers have changed from their shortened form to a longer form
that is more intuitive. `'c'` is now `'ctrl'`, `'a'` is now `'alt'`, `'m'` is
now `'cmd'` on macOS and `'meta'` in the terminal version, and `'s'` is now
`'shift'`. For example, `keys.cn = ...` is now `keys['ctrl+n'] = ...` and
`keys['m<'] = ...` is now `keys['cmd+<'] = ...` or `keys['meta+<'] = ...`.

The key binding for inserting a user-specified snippet from a dialog has changed
from `Ctrl+K` (`⌥⇥` on macOS | `M-K` on the terminal) to `Ctrl+Shift+K`
(`⌥⇧⇥` | `M-S-K`). `Ctrl+K` (`⌥⇥` | `M-K`) now autocompletes snippet names.

##### Session Changes

Textadept saves and loads session from Lua data files instead of structured text
files. As a result, Textadept 11 cannot load session files from 10.x or before.

##### Miscellaneous Changes

* *~/.textadept/?.lua* and *~/.textadept/?.{so,dll}* has been removed from
  `package.path` and `package.cpath`, respectively. All modules should be placed
  in *~/.textadept/modules/*.
* The command entry no longer recognizes a Lua 5.1-style '`=`' prefix for
  printing return values. Printing return values has been the default for quite
  some time.