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:

• $VIS_PATH/lexers
• ./lua/lexers relative to the binary location (using /proc/self/exe)
• $XDG_CONFIG_HOME/vis/lexers
• /usr/local/share/vis/lexers
• /usr/share/vis/lexers
• package.path (standard lua search path)

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.txt found in this directory 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 at the end of the vis.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. At startup the default.lua theme which should be a symlink to your prefered style is used. Themes can be changed at runtime via the :set theme <name> command where <name> does not include the .lua file extension.

Dependencies

• Lua 5.1 or greater
• LPeg 0.12 or greater