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, 63 insertions, 0 deletions

diff --git a/lua/lexers/vbscript.lua b/lua/lexers/vbscript.lua
new file mode 100644
index 0000000..1fcc6d7
--- /dev/null
+++ b/lua/lexers/vbscript.lua
@@ -0,0 +1,63 @@
+-- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
+-- VisualBasic 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 = 'vbscript'}
+
+-- Whitespace.
+local ws = token(l.WHITESPACE, l.space^1)
+
+-- Comments.
+local comment = token(l.COMMENT, (P("'") + word_match({'rem'}, nil, true)) * l.nonnewline^0)
+
+-- Strings.
+local string = token(l.STRING, l.delimited_range('"', true, true))
+
+-- Numbers.
+local number = token(l.NUMBER, (l.float + l.integer) * S('LlUuFf')^-2)
+
+-- Keywords.
+local keyword = token(l.KEYWORD, word_match({
+  -- Control.
+  'If', 'Then', 'Else', 'ElseIf', 'While', 'Wend', 'For', 'To', 'Each',
+  'In', 'Step', 'Case', 'Select', 'Return', 'Continue', 'Do',
+  'Until', 'Loop', 'Next', 'With', 'Exit',
+  -- Operators.
+  'Mod', 'And', 'Not', 'Or', 'Xor', 'Is',
+  -- Storage types.
+  'Call', 'Class', 'Const', 'Dim', 'ReDim', 'Preserve', 'Function', 'Sub',
+  'Property', 'End', 'Set', 'Let', 'Get', 'New', 'Randomize', 'Option',
+  'Explicit', 'On', 'Error', 'Execute',
+  -- Storage modifiers.
+  'Private', 'Public', 'Default',
+  -- Constants.
+  'Empty', 'False', 'Nothing', 'Null', 'True'
+}, nil, true))
+
+-- Types.
+local type = token(l.TYPE, word_match({
+  'Boolean', 'Byte', 'Char', 'Date', 'Decimal', 'Double', 'Long', 'Object',
+  'Short', 'Single', 'String'
+}, nil, true))
+
+-- Identifiers.
+local identifier = token(l.IDENTIFIER, l.word)
+
+-- Operators.
+local operator = token(l.OPERATOR, S('=><+-*^&:.,_()'))
+
+M._rules = {
+  {'whitespace', ws},
+  {'keyword', keyword},
+  {'type', type},
+  {'comment', comment},
+  {'identifier', identifier},
+  {'string', string},
+  {'number', number},
+  {'operator', operator},
+}
+
+return M