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, 115 deletions

diff --git a/lexers/yaml.lua b/lexers/yaml.lua
deleted file mode 100644
index 2263f3f..0000000
--- a/lexers/yaml.lua
+++ /dev/null
@@ -1,115 +0,0 @@
--- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
--- YAML LPeg lexer.
--- It does not keep track of indentation perfectly.
-
-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 = 'yaml'}
-
--- Whitespace.
-local indent = #l.starts_line(S(' \t')) *
-               (token(l.WHITESPACE, ' ') + token('indent_error', '\t'))^1
-local ws = token(l.WHITESPACE, S(' \t')^1 + l.newline^1)
-
--- Comments.
-local comment = token(l.COMMENT, '#' * l.nonnewline^0)
-
--- Strings.
-local string = token(l.STRING, l.delimited_range("'") + l.delimited_range('"'))
-
--- Numbers.
-local integer = l.dec_num + l.hex_num + '0' * S('oO') * R('07')^1
-local special_num = '.' * word_match({'inf', 'nan'}, nil, true)
-local number = token(l.NUMBER, special_num + l.float + integer)
-
--- Timestamps.
-local ts = token('timestamp', l.digit * l.digit * l.digit * l.digit * -- year
-                              '-' * l.digit * l.digit^-1 * -- month
-                              '-' * l.digit * l.digit^-1 * -- day
-                              ((S(' \t')^1 + S('tT'))^-1 * -- separator
-                               l.digit * l.digit^-1 * -- hour
-                               ':' * l.digit * l.digit * -- minute
-                               ':' * l.digit * l.digit * -- second
-                               ('.' * l.digit^0)^-1 * -- fraction
-                               ('Z' + -- timezone
-                                S(' \t')^0 * S('-+') * l.digit * l.digit^-1 *
-                                (':' * l.digit * l.digit)^-1)^-1)^-1)
-
--- Constants.
-local constant = token(l.CONSTANT,
-                       word_match({'null', 'true', 'false'}, nil, true))
-
--- Types.
-local type = token(l.TYPE, '!!' * word_match({
-  -- Collection types.
-  'map', 'omap', 'pairs', 'set', 'seq',
-  -- Scalar types.
-  'binary', 'bool', 'float', 'int', 'merge', 'null', 'str', 'timestamp',
-  'value', 'yaml'
-}, nil, true) + '!' * l.delimited_range('<>'))
-
--- Document boundaries.
-local doc_bounds = token('document', l.starts_line(P('---') + '...'))
-
--- Directives
-local directive = token('directive', l.starts_line('%') * l.nonnewline^1)
-
-local word = (l.alpha + '-' * -l.space) * (l.alnum + '-')^0
-
--- Keys and literals.
-local colon = S(' \t')^0 * ':' * (l.space + -1)
-local key = token(l.KEYWORD,
-                  #word * (l.nonnewline - colon)^1 * #colon *
-                  P(function(input, index)
-                    local line = input:sub(1, index - 1):match('[^\r\n]+$')
-                    return not line:find('[%w-]+:') and index
-                  end))
-local value = #word * (l.nonnewline - l.space^0 * S(',]}'))^1
-local block = S('|>') * S('+-')^-1 * (l.newline + -1) * function(input, index)
-  local rest = input:sub(index)
-  local level = #rest:match('^( *)')
-  for pos, indent, line in rest:gmatch('() *()([^\r\n]+)') do
-    if indent - pos < level and line ~= ' ' or level == 0 and pos > 1 then
-      return index + pos - 1
-    end
-  end
-  return #input + 1
-end
-local literal = token('literal', value + block)
-
--- Indicators.
-local anchor = token(l.LABEL, '&' * word)
-local alias = token(l.VARIABLE, '*' * word)
-local tag = token('tag', '!' * word * P('!')^-1)
-local reserved = token(l.ERROR, S('@`') * word)
-local indicator_chars = token(l.OPERATOR, S('-?:,[]{}!'))
-
-M._rules = {
-  {'indent', indent},
-  {'whitespace', ws},
-  {'comment', comment},
-  {'doc_bounds', doc_bounds},
-  {'key', key},
-  {'literal', literal},
-  {'timestamp', ts},
-  {'number', number},
-  {'constant', constant},
-  {'type', type},
-  {'indicator', tag + indicator_chars + alias + anchor + reserved},
-  {'directive', directive},
-}
-
-M._tokenstyles = {
-  indent_error = 'back:red',
-  document = l.STYLE_CONSTANT,
-  literal = l.STYLE_DEFAULT,
-  timestamp = l.STYLE_NUMBER,
-  tag = l.STYLE_CLASS,
-  directive = l.STYLE_PREPROCESSOR,
-}
-
-M._FOLDBYINDENTATION = true
-
-return M