Lua LPeg lexers for vis

Vis reuses the Lua LPeg based lexers from the Scintillua project.

Vis integration

Vis searches the lexers in the following locations (check the end of the :help output for the exact paths used by your binary):

• $VIS_PATH/lexers
• ./lua/lexers relative to the binary location (using /proc/self/exe)
• $XDG_CONFIG_HOME/vis/lexers where $XDG_CONFIG_HOME refers to $HOME/.config if unset.
• /etc/vis/lexers
• /usr/local/share/vis/lexers or /usr/share/vis/lexers depending on the build configuration
• package.path the standard Lua search path is queried for lexers/$name

At runtime a specific lexer can be loded by means of :set syntax <name> where <name> corresponds to the filename without the .lua extension.

Adding new lexers

To add a new lexer, start with the template quoted below or a lexer of a similiar language. Read the lexer module documentation. The LPeg introduction might also be useful.

For development purposes it is recommended to test the lexers from a lua script as described in the Scintillua manual.

To enable auto syntax highlighting when opening a file you can associate your new lexer with a set of file extensions by adding a corresponding entry into the table found in plugins/filetype.lua file.

Changes to existing lexers should also be sent upstream for consideration.

A template for new lexers:

-- ? LPeg lexer.

local l = require('lexer')
local token, word_match = l.token, l.word_match
local P, R, S = lpeg.P, lpeg.R, lpeg.S

local M = {_NAME = '?'}

-- Whitespace.
local ws = token(l.WHITESPACE, l.space^1)

M._rules = {
  {'whitespace', ws},
}

M._tokenstyles = {

}

return M

Color Themes

The ../themes directory contains the color schemes. Depending on the number of colors supported by your terminal, vis will start with either the default-16 or default-256 theme. Symlink it to your prefered style or add a command like the following one to your visrc.lua:

vis:command("set theme solarized")

Dependencies

• Lua 5.1 or greater
• LPeg 0.12 or greater