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, 47 insertions, 0 deletions

diff --git a/lua/lexers/props.lua b/lua/lexers/props.lua
new file mode 100644
index 0000000..5602787
--- /dev/null
+++ b/lua/lexers/props.lua
@@ -0,0 +1,47 @@
+-- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
+-- Props 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 = 'props'}
+
+-- Whitespace.
+local ws = token(l.WHITESPACE, l.space^1)
+
+-- Comments.
+local comment = token(l.COMMENT, '#' * l.nonnewline^0)
+
+-- Equals.
+local equals = token(l.OPERATOR, '=')
+
+-- Strings.
+local sq_str = l.delimited_range("'")
+local dq_str = l.delimited_range('"')
+local string = token(l.STRING, sq_str + dq_str)
+
+-- Variables.
+local variable = token(l.VARIABLE, '$(' * (l.any - ')')^1 * ')')
+
+-- Colors.
+local xdigit = l.xdigit
+local color = token('color', '#' * xdigit * xdigit * xdigit * xdigit * xdigit *
+                             xdigit)
+
+M._rules = {
+  {'whitespace', ws},
+  {'color', color},
+  {'comment', comment},
+  {'equals', equals},
+  {'string', string},
+  {'variable', variable},
+}
+
+M._tokenstyles = {
+  color = l.STYLE_NUMBER
+}
+
+M._LEXBYLINE = true
+
+return M