Move all lua related files to lua/ subfolder

Also remove the lexers sub directory from the Lua search path.
As a result we attempt to open fewer files during startup:

 $ strace -e open -o log ./vis +q config.h && wc -l log

In order to avoid having to modifiy all lexers which `require('lexer')`
we instead place a symlink in the top level directory.

 $ ./configure --disable-lua
 $ rm -rf lua

Should result in a source tree with most lua specifc functionality
removed.

1 files changed, 21 insertions, 0 deletions

diff --git a/lua/lexers/litcoffee.lua b/lua/lexers/litcoffee.lua
new file mode 100644
index 0000000..f31a2d1
--- /dev/null
+++ b/lua/lexers/litcoffee.lua
@@ -0,0 +1,21 @@
+-- Copyright 2006-2013 Robert Gieseke. See LICENSE.
+-- Literate CoffeeScript LPeg lexer.
+-- http://coffeescript.org/#literate
+
+local l = require('lexer')
+local token = l.token
+local P = lpeg.P
+
+local M = {_NAME = 'litcoffee'}
+
+-- Embedded in Markdown.
+local markdown = l.load('markdown')
+M._lexer = markdown -- ensure markdown's rules are loaded, not HTML's
+
+-- Embedded CoffeeScript.
+local coffeescript = l.load('coffeescript')
+local coffee_start_rule = token(l.STYLE_EMBEDDED, (P(' ')^4 + P('\t')))
+local coffee_end_rule = token(l.STYLE_EMBEDDED, l.newline)
+l.embed_lexer(markdown, coffeescript, coffee_start_rule, coffee_end_rule)
+
+return M