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, 60 deletions

diff --git a/lexers/haskell.lua b/lexers/haskell.lua
deleted file mode 100644
index de247e1..0000000
--- a/lexers/haskell.lua
+++ /dev/null
@@ -1,60 +0,0 @@
--- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
--- Haskell LPeg lexer.
--- Modified by Alex Suraci.
-
-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 = 'haskell'}
-
--- 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 string = token(l.STRING, l.delimited_range('"'))
-
--- Chars.
-local char = token(l.STRING, l.delimited_range("'", true))
-
--- Numbers.
-local number = token(l.NUMBER, l.float + l.integer)
-
--- Keywords.
-local keyword = token(l.KEYWORD, word_match{
-  'case', 'class', 'data', 'default', 'deriving', 'do', 'else', 'if', 'import',
-  'in', 'infix', 'infixl', 'infixr', 'instance', 'let', 'module', 'newtype',
-  'of', 'then', 'type', 'where', '_', 'as', 'qualified', 'hiding'
-})
-
--- Identifiers.
-local word = (l.alnum + S("._'#"))^0
-local identifier = token(l.IDENTIFIER, (l.alpha + '_') * word)
-
--- Operators.
-local op = l.punct - S('()[]{}')
-local operator = token(l.OPERATOR, op)
-
--- Types & type constructors.
-local constructor = token(l.TYPE, (l.upper * word) + (P(":") * (op^1 - P(":"))))
-
-M._rules = {
-  {'whitespace', ws},
-  {'keyword', keyword},
-  {'type', constructor},
-  {'identifier', identifier},
-  {'string', string},
-  {'char', char},
-  {'comment', comment},
-  {'number', number},
-  {'operator', operator},
-}
-
-M._FOLDBYINDENTATION = true
-
-return M