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, 62 insertions, 0 deletions

diff --git a/lua/lexers/coffeescript.lua b/lua/lexers/coffeescript.lua
new file mode 100644
index 0000000..366d390
--- /dev/null
+++ b/lua/lexers/coffeescript.lua
@@ -0,0 +1,62 @@
+-- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
+-- CoffeeScript LPeg lexer.
+
+local l = require('lexer')
+local token, word_match = l.token, l.word_match
+local P, S = lpeg.P, lpeg.S
+
+local M = {_NAME = 'coffeescript'}
+
+-- Whitespace.
+local ws = token(l.WHITESPACE, l.space^1)
+
+-- Comments.
+local block_comment = '###' * (l.any - '###')^0 * P('###')^-1
+local line_comment = '#' * l.nonnewline_esc^0
+local comment = token(l.COMMENT, block_comment + line_comment)
+
+-- Strings.
+local sq_str = l.delimited_range("'")
+local dq_str = l.delimited_range('"')
+local regex_str = #P('/') * l.last_char_includes('+-*%<>!=^&|?~:;,([{') *
+                  l.delimited_range('/', true) * S('igm')^0
+local string = token(l.STRING, sq_str + dq_str) + token(l.REGEX, regex_str)
+
+-- Numbers.
+local number = token(l.NUMBER, l.float + l.integer)
+
+-- Keywords.
+local keyword = token(l.KEYWORD, word_match{
+  'all', 'and', 'bind', 'break', 'by', 'case', 'catch', 'class', 'const',
+  'continue', 'default', 'delete', 'do', 'each', 'else', 'enum', 'export',
+  'extends', 'false', 'for', 'finally', 'function', 'if', 'import', 'in',
+  'instanceof', 'is', 'isnt', 'let', 'loop', 'native', 'new', 'no', 'not', 'of',
+  'off', 'on', 'or', 'return', 'super', 'switch', 'then', 'this', 'throw',
+  'true', 'try', 'typeof', 'unless', 'until', 'var', 'void', 'with', 'when',
+  'while', 'yes'
+})
+
+-- Fields: object properties and methods.
+local field = token(l.FUNCTION, '.' * (S('_$') + l.alpha) *
+                                (S('_$') + l.alnum)^0)
+
+-- Identifiers.
+local identifier = token(l.IDENTIFIER, l.word)
+
+-- Operators.
+local operator = token(l.OPERATOR, S('+-/*%<>!=^&|?~:;,.()[]{}'))
+
+M._rules = {
+  {'whitespace', ws},
+  {'keyword', keyword},
+  {'field', field},
+  {'identifier', identifier},
+  {'comment', comment},
+  {'number', number},
+  {'string', string},
+  {'operator', operator},
+}
+
+M._FOLDBYINDENTATION = true
+
+return M