Lua layer

Table of ContentsClose

1. Description
- 1.1. Features:
2. Install
- 2.1. Layer
- 2.2. Backends
  - 2.2.1. Lua mode
  - 2.2.2. LSP
3. Key bindings
- 3.1. LSP
- 3.2. Commands

1. Description

This layer adds support for editing Lua.

1.1. Features:

Editing lua files using lua-mode
Code-Completion with lsp or company-lua
Sending code to a lua REPL
Code linting using Luacheck
Cross references (definitions, references, rename…)

2. Install

2.1. Layer

To use this configuration layer, add it to your ~/.spacemacs. You will need to add lua to the existing dotspacemacs-configuration-layers list in this file.

In order to enable code linting, install Luacheck.

2.2. Backends

Supported backends are:

lua-mode using emacs packages
lsp using one of below LSP servers
- emmy LSP server (default)
- lua-language-server.
- lua-lsp.

2.2.1. Lua mode

This backend provides basic support via pure emacs packages. It requires less setup than a full blown LSP setup but also provides less features. To enable it set the lua-backend to lua-mode.

(lua :variables
     lua-backend 'lua-mode)

2.2.2. LSP

This is the prefered backend choice. It relies on an external server implementing the LSP protocol. It requires installing one of the supported server implementations below:

Once it is installed the key bindings are provided by LSP layer allowing consistent key bindings among different layers.

To enable LSP set lua-backend to lsp. If lua-backend is nil and the LSP layer is loaded LSP will be used automatically otherwise it will fallback to lua-mode.

(lua :variables
     lua-backend 'lsp)

Emmy server setup
To use the emmy lsp server, please download the EmmyLua-LS-all.jar and put it into ~/.emacs.d/. Then set the layer variable lua-lsp-server to emmy. This is also the default choice if no specific lsp server has been selected.

emmy requires a working java installation in the path as well as the path to the LSP server jar. The java path and the path to the server executable can be configured as is shown below:
```
(lua :variables
     lua-backend 'lsp
     lua-lsp-server 'emmy
     lsp-clients-emmy-lua-jar-path "~/.emacs.d/.cache/lsp/EmmyLua-LS-all.jar" ; default path
     lsp-clients-emmy-lua-java-path "java") ; default path
```

Lua-language server setup

To use the lua-language-server lsp server, please follow lua-language-server to compile the standalone binary. Then set the layer variables as shown below:

(lua :variables
     lua-backend 'lsp
     lua-lsp-server 'lua-language-server
     lsp-clients-lua-language-server-bin "~/.emacs.d/.cache/lsp/lua-language-server/bin/Linux/lua-language-server" ; default path
     lsp-clients-lua-language-server-main-location "~/.emacs.d/.cache/lsp/lua-language-server/main.lua") ; default path

Lua-lsp server setup
To use the lua-lsp lsp server, please follow lua-lsp to install the server via luarocks. Remember that the capabilities of this server are mainly dependent on the installed luarocks packages, so make sure you have them all installed for maximum benefit.

To instruct Spacemacs to use this server set your config as shown below:
```
(lua :variables
     lua-backend 'lsp
     lua-lsp-server 'lua-lsp
     lsp-clients-luarocks-bin-dir "~/.luarocks/bin/") ; default path
```

3. Key bindings

3.1. LSP

The default key bindings for the LSP implementations are defined and documented in the LSP layer.

3.2. Commands

Key binding	Description
`SPC m d`	lookup thing at point in lua documentation
`SPC m s b`	send buffer contents to REPL
`SPC m s f`	send current function to REPL
`SPC m s l`	send current line to REPL
`SPC m s r`	send current region to REPL
`SPC m '`	open repl buffer