# Preferences

At this point the manual assumes you are at least familiar with the basics of
[Lua][]. You do not have to know a lot of the language to configure Textadept.

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

## User Init

Textadept executes a *~/.textadept/init.lua*, your user-init file, on startup.
If this file does not exist, Textadept creates it for you. This file allows you
to indicate what you want Textadept to do when the application starts, such as
change the settings of existing modules, load new ones, and/or run plain Lua
code.

### Modules

Try to refrain from modifying the default modules that come with Textadept, even
if you just want to change an option in a generic module, modify the buffer
settings for a language-specific module, edit file types, or add a small bit of
custom code. Upgrading Textadept to a new version may overwrite those changes.
Instead you have two options: load your own module instead of the default one,
or run your custom module code after the default module loads. For the most
part, use the second option because it is simpler and more compatible with
future releases. The manual discusses both options below in the context of
generic and language-specific modules.

#### Generic

Many of Textadept's generic modules have configurable settings changeable from
*~/.textadept/init.lua* after Textadept loads the module. The module's
[LuaDoc][] lists these settings. For example, to disable character autopairing
with typeover and stripping whitespace on save, add the following to your
*~/.textadept/init.lua*:

    _M.textadept.editing.AUTOPAIR = false
    _M.textadept.editing.TYPEOVER_CHARS = false
    _M.textadept.editing.STRIP_TRAILING_SPACES = false

Now suppose you want to load all of Textadept's default modules except for the
menu. You cannot do this after-the-fact from *~/.textadept/init.lua*. Instead
you need Textadept to load your own module rather than the default one. Copy the
`textadept` module's *init.lua* (located in the *modules/textadept/* directory)
to *~/.textadept/modules/textadept/* and change

    M.menu = require 'textadept.menu'

to

    --M.menu = require 'textadept.menu'

Now when Textadept looks for *modules/textadept/init.lua*, it loads yours in
place of its own, thus loading everything but the menu. If instead you want to
completely change the menu structure, first create a new *menu.lua* and then put
it in *~/.textadept/modules/textadept/*. Textadept now loads your *menu.lua*
rather than its own.

[LuaDoc]: api/index.html

#### Language-Specific

Similar to generic modules, putting your own language-specific module in
*~/.textadept/modules/* causes Textadept to load that module for editing the
language's code instead of the default one in *modules/* (if the latter exists).
For example, copying the default Lua language-specific module from
*modules/lua/* to *~/.textadept/modules/* results in Textadept loading that
module for editing Lua code in place of its own. However, if you make custom
changes to that module and upgrade Textadept later, the module may no longer be
compatible. Rather than potentially wasting time merging changes, run custom
code independent of a module in the module's *post_init.lua* file. In this case,
instead of copying the `lua` module and creating an
`events.LANGUAGE_MODULE_LOADED` event handler to use tabs, simply put the event
handler in *~/.textadept/modules/lua/post_init.lua*:

    events.connect(events.LANGUAGE_MODULE_LOADED, function(lang)
      if lang == 'lua' then buffer.use_tabs = true end
    end)

Similarly, use *post_init.lua* to change the module's [compile and run][]
commands, load more [Adeptsense tags][], and add additional
[key bindings](#Key.Bindings) and [snippets](#Snippets) (instead of in
*~/.textadept/init.lua*). For example:

    _M.textadept.run.run_command.lua = 'lua5.2'
    _M.lua.sense:load_ctags('/path/to/my/projects/tags')
    keys.lua['c\n'] = function()
      buffer:line_end() buffer:add_text('end') buffer:new_line()
    end
    snippets.lua['ver'] = '%<_VERSION>'

[compile and run]: 07_Modules.html#Compile.and.Run
[Adeptsense tags]: api/_M.textadept.adeptsense.html#load_ctags

### Loading Modules

After creating or downloading a generic module called `foo` that you want to
load along with the default modules, simply add the following to your
*~/.textadept/init.lua*:

    _M.foo = require 'foo'

Textadept automatically loads language-specific modules when opening a source
file of that language, so simply installing the language-specific module is
sufficient.

### Key Bindings

For simple changes to key bindings, *~/.textadept/init.lua* is a good place to
put them. For example, maybe you want `Ctrl+Shift+C` to create a new buffer
instead of `Ctrl+N`:

    keys.cC = buffer.new
    keys.cn = nil

If you plan on redefining most key bindings, copy or create a new *keys.lua* and
put it in *~/.textadept/modules/textadept/* to get Textadept to load your set
instead of its own. Learn more about key bindings and how to define them in the
[key bindings LuaDoc][].

[key bindings LuaDoc]: api/keys.html

### Snippets

Define your own global snippets in *~/.textadept/init.lua*, such as:

    snippets['file'] = '%<buffer.filename>'
    snippets['path'] = "%<(buffer.filename or ''):match('^.+[/\\]')>"

So typing `file` or `path` and then pressing `Tab` (`⇥` on Mac OSX | `Tab` in
curses) inserts the snippet, regardless of the current programming language.
Learn more about snippet syntax in the [snippets LuaDoc][].

[snippets LuaDoc]: api/_M.textadept.snippets.html

## Buffer Properties

Since Textadept runs *~/.textadept/init.lua* only once on startup, it is not the
appropriate place to set per-buffer properties like indentation size or
view-related properties like the behaviors for scrolling and autocompletion.
If you do set such properties in *~/.textadept/init.lua*, those settings only
apply to the first buffer and view -- subsequent buffers and split views will
not inherit those settings. Instead, put your settings in a
*~/.textadept/properties.lua* file which runs after creating a new buffer or
split view. Any settings there override Textadept's default *properties.lua*
settings. For example, to use tabs rather than spaces and have a tab size of 4
spaces by default, your *~/.textadept/properties.lua* would contain:

    buffer.tab_width = 4
    buffer.use_tabs = true

(Remember that in order to have per-filetype properties, you need to have a
[language-specific module][].)

Textadept's *properties.lua* is a good reference to see available properties to
set. It also has many commented out properties that you can copy to your
*~/.textadept/properties.lua* and uncomment to turn on or change the value of.
Use [Adeptsense][] to view a property's documentation or read the [LuaDoc][].

[language-specific module]: 07_Modules.html#Buffer.Properties
[Adeptsense]: 06_AdeptEditing.html#Adeptsense
[LuaDoc]: api/buffer.html

## Locale

Textadept attempts to auto-detect your locale settings using the "$LANG"
environment variable, falling back on the English locale. To set the locale
manually, copy the desired locale file from the *core/locales/* folder to
*~/.textadept/locale.conf*. If Textadept does not support your language yet,
please translate the English messages in *core/locale.conf* to your language and
send the modified *locale.conf* file to [me][]. I will include it in a future
release.

[me]: README.html#Contact

## File Types

Textadept recognizes a wide range of programming language files by any of the
following:

* File extension.
* Keywords in the file's shebang ("#!/path/to/exe") line.
* A pattern that matches the text of the file's first line.

*modules/textadept/mime_types.conf* contains built-in file types. Override or
add to them in your *~/.textadept/mime_types.conf*:

    % Recognize .luadoc files as Lua code.
    luadoc lua

    % Change .html files to be recognized as XML files.
    html xml

### Detect by Extension

The syntax for mapping a file extension to a lexer is:

    file_ext lexer

Note: `file_ext` should not start with a '.' (period).

### Detect by Shebang

The syntax for mapping a word contained in a shebang line (the first line of a
file whose first two characters are "#!") to a lexer is:

    #shebang_word lexer

Examples of `shebang_word`s are "lua", "ruby", "python" which match lines like
"#!/usr/bin/lua", "#!/usr/env/ruby", and "#!/usr/bin/python3", respectively.

### Detect by Pattern

The syntax for mapping a Lua pattern that matches the first line of a file to a
lexer is:

    /pattern lexer

Patterns use [Lua pattern syntax][] with only the last space, the one separating
the pattern from the lexer, being significant. No spaces in the pattern need
escaping.

[Lua pattern syntax]: 14_Appendix.html#Lua.Patterns