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, 64 insertions, 0 deletions

diff --git a/lua/lexers/javascript.lua b/lua/lexers/javascript.lua
new file mode 100644
index 0000000..f879948
--- /dev/null
+++ b/lua/lexers/javascript.lua
@@ -0,0 +1,64 @@
+-- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
+-- JavaScript 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 = 'javascript'}
+
+-- Whitespace.
+local ws = token(l.WHITESPACE, l.space^1)
+
+-- Comments.
+local line_comment = '//' * l.nonnewline_esc^0
+local block_comment = '/*' * (l.any - '*/')^0 * P('*/')^-1
+local comment = token(l.COMMENT, line_comment + block_comment)
+
+-- Strings.
+local sq_str = l.delimited_range("'")
+local dq_str = l.delimited_range('"')
+local template_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 + template_str) +
+               token(l.REGEX, regex_str)
+
+-- Numbers.
+local number = token(l.NUMBER, l.float + l.integer)
+
+-- Keywords.
+local keyword = token(l.KEYWORD, word_match{
+  'abstract', 'boolean', 'break', 'byte', 'case', 'catch', 'char', 'class',
+  'const', 'continue', 'debugger', 'default', 'delete', 'do', 'double', 'else',
+  'enum', 'export', 'extends', 'false', 'final', 'finally', 'float', 'for',
+  'function', 'goto', 'if', 'implements', 'import', 'in', 'instanceof', 'int',
+  'interface', 'let', 'long', 'native', 'new', 'null', 'of', 'package',
+  'private', 'protected', 'public', 'return', 'short', 'static', 'super',
+  'switch', 'synchronized', 'this', 'throw', 'throws', 'transient', 'true',
+  'try', 'typeof', 'var', 'void', 'volatile', 'while', 'with', 'yield'
+})
+
+-- Identifiers.
+local identifier = token(l.IDENTIFIER, l.word)
+
+-- Operators.
+local operator = token(l.OPERATOR, S('+-/*%^!=&|?:;,.()[]{}<>'))
+
+M._rules = {
+  {'whitespace', ws},
+  {'keyword', keyword},
+  {'identifier', identifier},
+  {'comment', comment},
+  {'number', number},
+  {'string', string},
+  {'operator', operator},
+}
+
+M._foldsymbols = {
+  _patterns = {'[{}]', '/%*', '%*/', '//'},
+  [l.OPERATOR] = {['{'] = 1, ['}'] = -1},
+  [l.COMMENT] = {['/*'] = 1, ['*/'] = -1, ['//'] = l.fold_line_comments('//')}
+}
+
+return M