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, 68 insertions, 0 deletions

diff --git a/lua/lexers/ada.lua b/lua/lexers/ada.lua
new file mode 100644
index 0000000..7258431
--- /dev/null
+++ b/lua/lexers/ada.lua
@@ -0,0 +1,68 @@
+-- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
+-- Ada 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 = 'ada'}
+
+-- Whitespace.
+local ws = token(l.WHITESPACE, l.space^1)
+
+-- Comments.
+local comment = token(l.COMMENT, '--' * l.nonnewline^0)
+
+-- Strings.
+local string = token(l.STRING, l.delimited_range('"', true, true))
+
+-- Numbers.
+local hex_num = 'O' * S('xX') * (l.xdigit + '_')^1
+local integer = l.digit^1 * ('_' * l.digit^1)^0
+local float = integer^1 * ('.' * integer^0)^-1 * S('eE') * S('+-')^-1 * integer
+local number = token(l.NUMBER, hex_num + S('+-')^-1 * (float + integer) *
+                               S('LlUuFf')^-3)
+
+-- Keywords.
+local keyword = token(l.KEYWORD, word_match{
+  'abort', 'abs', 'accept', 'all', 'and', 'begin', 'body', 'case', 'declare',
+  'delay', 'do', 'else', 'elsif', 'end', 'entry', 'exception', 'exit', 'for',
+  'generic', 'goto', 'if', 'in', 'is', 'loop', 'mod', 'new', 'not', 'null',
+  'or', 'others', 'out', 'protected', 'raise', 'record', 'rem', 'renames',
+  'requeue', 'reverse', 'select', 'separate', 'subtype', 'task', 'terminate',
+  'then', 'type', 'until', 'when', 'while', 'xor',
+  -- Preprocessor.
+  'package', 'pragma', 'use', 'with',
+  -- Function
+  'function', 'procedure', 'return',
+  -- Storage class.
+  'abstract', 'access', 'aliased', 'array', 'at', 'constant', 'delta', 'digits',
+  'interface', 'limited', 'of', 'private', 'range', 'tagged', 'synchronized',
+  -- Boolean.
+  'true', 'false'
+})
+
+-- Types.
+local type = token(l.TYPE, word_match{
+  'boolean', 'character', 'count', 'duration', 'float', 'integer', 'long_float',
+  'long_integer', 'priority', 'short_float', 'short_integer', 'string'
+})
+
+-- 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