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, 59 deletions

diff --git a/lexers/tcl.lua b/lexers/tcl.lua
deleted file mode 100644
index f76e6ee..0000000
--- a/lexers/tcl.lua
+++ /dev/null
@@ -1,59 +0,0 @@
--- Copyright 2014-2016 Joshua Krämer. See LICENSE.
--- Tcl LPeg lexer.
--- This lexer follows the TCL dodekalogue (http://wiki.tcl.tk/10259).
--- It is based on the previous lexer by Mitchell.
-
-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 = 'tcl'}
-
--- Whitespace.
-local whitespace = token(l.WHITESPACE, l.space^1)
-
--- Separator (semicolon).
-local separator = token(l.CLASS, P(';'))
-
--- Delimiters.
-local braces = token(l.KEYWORD, S('{}'))
-local quotes = token(l.FUNCTION, '"')
-local brackets = token(l.VARIABLE, S('[]'))
-
--- Argument expander.
-local expander = token(l.LABEL, P('{*}'))
-
--- Variable substitution.
-local variable = token(l.STRING, '$' * (l.alnum + '_' + P(':')^2)^0)
-
--- Backslash substitution.
-local backslash = token(l.TYPE, '\\' * ((l.digit * l.digit^-2) +
-                        ('x' * l.xdigit^1) + ('u' * l.xdigit * l.xdigit^-3) +
-                        ('U' * l.xdigit * l.xdigit^-7) + P(1)))
-
--- Comment.
-local comment = token(l.COMMENT, '#' * P(function(input, index)
-  local i = index - 2
-  while i > 0 and input:find('^[ \t]', i) do i = i - 1 end
-  if i < 1 or input:find('^[\r\n;]', i) then return index end
-end) * l.nonnewline^0)
-
-M._rules = {
-  {'whitespace', whitespace},
-  {'comment', comment},
-  {'separator', separator},
-  {'expander', expander},
-  {'braces', braces},
-  {'quotes', quotes},
-  {'brackets', brackets},
-  {'variable', variable},
-  {'backslash', backslash},
-}
-
-M._foldsymbols = {
-  _patterns = {'[{}]', '#'},
-  [l.KEYWORD] = {['{'] = 1, ['}'] = -1},
-  [l.COMMENT] = {['#'] = l.fold_line_comments('#')}
-}
-
-return M