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, 76 insertions, 0 deletions

diff --git a/lua/lexers/fsharp.lua b/lua/lexers/fsharp.lua
new file mode 100644
index 0000000..383ab6a
--- /dev/null
+++ b/lua/lexers/fsharp.lua
@@ -0,0 +1,76 @@
+-- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
+-- F# 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 = 'fsharp'}
+
+-- Whitespace.
+local ws = token(l.WHITESPACE, l.space^1)
+
+-- Comments.
+local line_comment = P('//') * l.nonnewline^0
+local block_comment = l.nested_pair('(*', '*)')
+local comment = token(l.COMMENT, line_comment + block_comment)
+
+-- Strings.
+local sq_str = l.delimited_range("'", true)
+local dq_str = l.delimited_range('"', true)
+local string = token(l.STRING, sq_str + dq_str)
+
+-- Numbers.
+local number = token(l.NUMBER, (l.float + l.integer * S('uUlL')^-1))
+
+-- Preprocessor.
+local preproc_word = word_match{
+  'ifndef', 'ifdef', 'if', 'else', 'endif', 'light', 'region', 'endregion'
+}
+local preproc = token(l.PREPROCESSOR,
+                      l.starts_line('#') * S('\t ')^0 * preproc_word *
+                      (l.nonnewline_esc^1 + l.space * l.nonnewline_esc^0))
+
+-- Keywords.
+local keyword = token(l.KEYWORD, word_match{
+  'abstract', 'and', 'as', 'assert', 'asr', 'begin', 'class', 'default',
+  'delegate', 'do', 'done', 'downcast', 'downto', 'else', 'end', 'enum',
+  'exception', 'false', 'finaly', 'for', 'fun', 'function', 'if', 'in',
+  'iherit', 'interface', 'land', 'lazy', 'let', 'lor', 'lsl', 'lsr', 'lxor',
+  'match', 'member', 'mod', 'module', 'mutable', 'namespace', 'new', 'null',
+  'of', 'open', 'or', 'override', 'sig', 'static', 'struct', 'then', 'to',
+  'true', 'try', 'type', 'val', 'when', 'inline', 'upcast', 'while', 'with',
+  'async', 'atomic', 'break', 'checked', 'component', 'const', 'constructor',
+  'continue', 'eager', 'event', 'external', 'fixed', 'functor', 'include',
+  'method', 'mixin', 'process', 'property', 'protected', 'public', 'pure',
+  'readonly', 'return', 'sealed', 'switch', 'virtual', 'void', 'volatile',
+  'where',
+  -- Booleans.
+  'true', 'false'
+})
+
+-- Types.
+local type = token(l.TYPE, word_match{
+  'bool', 'byte', 'sbyte', 'int16', 'uint16', 'int', 'uint32', 'int64',
+  'uint64', 'nativeint', 'unativeint', 'char', 'string', 'decimal', 'unit',
+  'void', 'float32', 'single', 'float', 'double'
+})
+
+-- 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