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, 0 insertions, 58 deletions

diff --git a/lexers/protobuf.lua b/lexers/protobuf.lua
deleted file mode 100644
index c257e7e..0000000
--- a/lexers/protobuf.lua
+++ /dev/null
@@ -1,58 +0,0 @@
--- Copyright 2016 David B. Lamkins <david@lamkins.net>. See LICENSE.
--- Protocol Buffer IDL LPeg lexer.
--- <https://developers.google.com/protocol-buffers/>
-
-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 = 'protobuf'}
-
--- 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 = P('L')^-1 * l.delimited_range("'", true)
-local dq_str = P('L')^-1 * l.delimited_range('"', true)
-local string = token(l.STRING, sq_str + dq_str)
-
--- Numbers.
-local number = token(l.NUMBER, l.float + l.integer)
-
--- Keywords.
-local keyword = token(l.KEYWORD, word_match{
-  'contained', 'syntax', 'import', 'option', 'package', 'message', 'group',
-  'oneof', 'optional', 'required', 'repeated', 'default', 'extend',
-  'extensions', 'to', 'max', 'reserved', 'service', 'rpc', 'returns'
-})
-
--- Types.
-local type = token(l.TYPE, word_match{
-  'int32', 'int64', 'uint32', 'uint64', 'sint32', 'sint64', 'fixed32',
-  'fixed64', 'sfixed32', 'sfixed64', 'float', 'double', 'bool', 'string',
-  'bytes', 'enum', 'true', 'false'
-})
-
--- 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},
-}
-
-return M