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, 37 insertions, 0 deletions

diff --git a/lua/lexers/man.lua b/lua/lexers/man.lua
new file mode 100644
index 0000000..557e11d
--- /dev/null
+++ b/lua/lexers/man.lua
@@ -0,0 +1,37 @@
+-- Copyright 2015-2016 David B. Lamkins <david@lamkins.net>. See LICENSE.
+-- man/roff 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 = 'man'}
+
+-- Whitespace.
+local ws = token(l.WHITESPACE, l.space^1)
+
+-- Markup.
+local rule1 = token(l.STRING,
+                    P('.') * (P('B') * P('R')^-1 + P('I') * P('PR')^-1) *
+                    l.nonnewline^0)
+local rule2 = token(l.NUMBER, P('.') * S('ST') * P('H') * l.nonnewline^0)
+local rule3 = token(l.KEYWORD,
+                    P('.br') + P('.DS') + P('.RS') + P('.RE') + P('.PD'))
+local rule4 = token(l.LABEL, P('.') * (S('ST') * P('H') + P('.TP')))
+local rule5 = token(l.VARIABLE,
+                    P('.B') * P('R')^-1 + P('.I') * S('PR')^-1 + P('.PP'))
+local rule6 = token(l.TYPE, P('\\f') * S('BIPR'))
+local rule7 = token(l.PREPROCESSOR, l.starts_line('.') * l.alpha^1)
+
+M._rules = {
+  {'whitespace', ws},
+  {'rule1', rule1},
+  {'rule2', rule2},
+  {'rule3', rule3},
+  {'rule4', rule4},
+  {'rule5', rule5},
+  {'rule6', rule6},
+  {'rule7', rule7},
+}
+
+return M