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/vala.lua b/lua/lexers/vala.lua
new file mode 100644
index 0000000..46f074c
--- /dev/null
+++ b/lua/lexers/vala.lua
@@ -0,0 +1,75 @@
+-- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
+-- Vala 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 = 'vala'}
+
+-- 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("'", true)
+local dq_str = l.delimited_range('"', true)
+local tq_str = '"""' * (l.any - '"""')^0 * P('"""')^-1
+local ml_str = '@' * l.delimited_range('"', false, true)
+local string = token(l.STRING, tq_str + sq_str + dq_str + ml_str)
+
+-- Numbers.
+local number = token(l.NUMBER, (l.float + l.integer) * S('uUlLfFdDmM')^-1)
+
+-- Keywords.
+local keyword = token(l.KEYWORD, word_match{
+  'class', 'delegate', 'enum', 'errordomain', 'interface', 'namespace',
+  'signal', 'struct', 'using',
+  -- Modifiers.
+  'abstract', 'const', 'dynamic', 'extern', 'inline', 'out', 'override',
+  'private', 'protected', 'public', 'ref', 'static', 'virtual', 'volatile',
+  'weak',
+  -- Other.
+  'as', 'base', 'break', 'case', 'catch', 'construct', 'continue', 'default',
+  'delete', 'do', 'else', 'ensures', 'finally', 'for', 'foreach', 'get', 'if',
+  'in', 'is', 'lock', 'new', 'requires', 'return', 'set', 'sizeof', 'switch',
+  'this', 'throw', 'throws', 'try', 'typeof', 'value', 'var', 'void', 'while',
+  -- Etc.
+  'null', 'true', 'false'
+})
+
+-- Types.
+local type = token(l.TYPE, word_match{
+  'bool', 'char', 'double', 'float', 'int', 'int8', 'int16', 'int32', 'int64',
+  'long', 'short', 'size_t', 'ssize_t', 'string', 'uchar', 'uint', 'uint8',
+  'uint16', 'uint32', 'uint64', 'ulong', 'unichar', 'ushort'
+})
+
+-- Identifiers.
+local identifier = token(l.IDENTIFIER, l.word)
+
+-- Operators.
+local operator = token(l.OPERATOR, S('+-/*%<>!=^&|?~:;.()[]{}'))
+
+M._rules = {
+  {'whitespace', ws},
+  {'keyword', keyword},
+  {'type', type},
+  {'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