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, 75 insertions, 0 deletions

diff --git a/lua/lexers/scala.lua b/lua/lexers/scala.lua
new file mode 100644
index 0000000..d455996
--- /dev/null
+++ b/lua/lexers/scala.lua
@@ -0,0 +1,75 @@
+-- Copyright 2006-2013 JMS. See LICENSE.
+-- Scala 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 = 'scala'}
+
+-- 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 symbol = "'" * l.word
+local dq_str = l.delimited_range('"', true)
+local tq_str = '"""' * (l.any - '"""')^0 * P('"""')^-1
+local string = token(l.STRING, tq_str + symbol + dq_str)
+
+-- Numbers.
+local number = token(l.NUMBER, (l.float + l.integer) * S('LlFfDd')^-1)
+
+-- Keywords.
+local keyword = token(l.KEYWORD, word_match{
+  'abstract', 'case', 'catch', 'class', 'def', 'do', 'else', 'extends', 'false',
+  'final', 'finally', 'for', 'forSome', 'if', 'implicit', 'import', 'lazy',
+  'match', 'new', 'null', 'object', 'override', 'package', 'private',
+  'protected', 'return', 'sealed', 'super', 'this', 'throw', 'trait', 'try',
+  'true', 'type', 'val', 'var', 'while', 'with', 'yield'
+})
+
+-- Types.
+local type = token(l.TYPE, word_match{
+  'Array', 'Boolean', 'Buffer', 'Byte', 'Char', 'Collection', 'Double', 'Float',
+  'Int', 'Iterator', 'LinkedList', 'List', 'Long', 'Map', 'None', 'Option',
+  'Set', 'Short', 'SortedMap', 'SortedSet', 'String', 'TreeMap', 'TreeSet'
+})
+
+-- Identifiers.
+local identifier = token(l.IDENTIFIER, l.word)
+
+-- Operators.
+local operator = token(l.OPERATOR, S('+-/*%<>!=^&|?~:;.()[]{}'))
+
+-- Functions.
+local func = token(l.FUNCTION, l.word) * #P('(')
+
+-- Classes.
+local class_sequence = token(l.KEYWORD, P('class')) * ws^1 *
+                       token(l.CLASS, l.word)
+
+M._rules = {
+  {'whitespace', ws},
+  {'class', class_sequence},
+  {'keyword', keyword},
+  {'type', type},
+  {'function', func},
+  {'identifier', identifier},
+  {'string', string},
+  {'comment', comment},
+  {'number', number},
+  {'operator', operator},
+}
+
+M._foldsymbols = {
+  _patterns = {'[{}]', '/%*', '%*/', '//'},
+  [l.OPERATOR] = {['{'] = 1, ['}'] = -1},
+  [l.COMMENT] = {['/*'] = 1, ['*/'] = -1, ['//'] = l.fold_line_comments('//')}
+}
+
+return M