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, 124 insertions, 0 deletions

diff --git a/lua/lexers/nim.lua b/lua/lexers/nim.lua
new file mode 100644
index 0000000..8fa438c
--- /dev/null
+++ b/lua/lexers/nim.lua
@@ -0,0 +1,124 @@
+-- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
+-- Nim 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 = 'nim'}
+
+-- Whitespace.
+local ws = token(l.WHITESPACE, l.space^1)
+
+-- Comments.
+local comment = token(l.COMMENT, '#' * l.nonnewline_esc^0)
+
+-- Strings.
+local sq_str = l.delimited_range("'", true)
+local dq_str = l.delimited_range('"', true)
+local triple_dq_str = '"""' * (l.any - '"""')^0 * P('"""')^-1
+local raw_dq_str = 'r' * l.delimited_range('"', false, true)
+local string = token(l.STRING, triple_dq_str + sq_str + dq_str + raw_dq_str)
+
+-- Numbers.
+local dec = l.digit^1 * ('_' * l.digit^1)^0
+local hex = '0' * S('xX') * l.xdigit^1 * ('_' * l.xdigit^1)^0
+local bin = '0' * S('bB') * S('01')^1 * ('_' * S('01')^1)^0
+local oct = '0o' * R('07')^1
+local integer = S('+-')^-1 * (bin + hex + oct + dec) *
+                ("'" * S('iIuUfF') * (P('8') + '16' + '32' + '64'))^-1
+local float = l.digit^1 * ('_' * l.digit^1)^0 * ('.' * ('_' * l.digit)^0)^-1 *
+              S('eE') * S('+-')^-1 * l.digit^1 * ('_' * l.digit^1)^0
+local number = token(l.NUMBER, l.float + integer)
+
+-- Keywords.
+local keyword = token(l.KEYWORD, word_match({
+  'addr', 'and', 'as', 'asm', 'atomic', 'bind', 'block', 'break', 'case',
+  'cast', 'const', 'continue', 'converter', 'discard', 'distinct', 'div', 'do',
+  'elif', 'else', 'end', 'enum', 'except', 'export', 'finally', 'for', 'from',
+  'generic', 'if', 'import', 'in', 'include', 'interface', 'is', 'isnot',
+  'iterator', 'lambda', 'let', 'macro', 'method', 'mixin', 'mod', 'nil', 'not',
+  'notin', 'object', 'of', 'or', 'out', 'proc', 'ptr', 'raise', 'ref', 'return',
+  'shared', 'shl', 'static', 'template', 'try', 'tuple', 'type', 'var', 'when',
+  'while', 'with', 'without', 'xor', 'yield'
+}, nil, true))
+
+-- Functions.
+local func = token(l.FUNCTION, word_match({
+  -- Procs.
+  'defined', 'definedInScope', 'new', 'unsafeNew', 'internalNew', 'reset',
+  'high', 'low', 'sizeof', 'succ', 'pred', 'inc', 'dec', 'newSeq', 'len',
+  'incl', 'excl', 'card', 'ord', 'chr', 'ze', 'ze64', 'toU8', 'toU16', 'toU32',
+  'abs', 'min', 'max', 'contains', 'cmp', 'setLen', 'newString',
+  'newStringOfCap', 'add', 'compileOption', 'quit', 'shallowCopy', 'del',
+  'delete', 'insert', 'repr', 'toFloat', 'toBiggestFloat', 'toInt',
+  'toBiggestInt', 'addQuitProc', 'substr', 'zeroMem', 'copyMem', 'moveMem',
+  'equalMem', 'swap', 'getRefcount', 'clamp', 'isNil', 'find',   'contains',
+  'pop', 'each', 'map', 'GC_ref', 'GC_unref', 'echo', 'debugEcho',
+  'getTypeInfo', 'Open', 'repopen', 'Close', 'EndOfFile', 'readChar',
+  'FlushFile', 'readAll', 'readFile', 'writeFile', 'write', 'readLine',
+  'writeln', 'getFileSize', 'ReadBytes', 'ReadChars', 'readBuffer',
+  'writeBytes', 'writeChars', 'writeBuffer', 'setFilePos', 'getFilePos',
+  'fileHandle', 'cstringArrayToSeq', 'allocCStringArray', 'deallocCStringArray',
+  'atomicInc', 'atomicDec', 'compareAndSwap', 'setControlCHook',
+  'writeStackTrace', 'getStackTrace', 'alloc', 'alloc0', 'dealloc', 'realloc',
+  'getFreeMem', 'getTotalMem', 'getOccupiedMem', 'allocShared', 'allocShared0',
+  'deallocShared', 'reallocShared', 'IsOnStack', 'GC_addCycleRoot',
+  'GC_disable', 'GC_enable', 'GC_setStrategy', 'GC_enableMarkAndSweep',
+  'GC_disableMarkAndSweep', 'GC_fullCollect', 'GC_getStatistics',
+  'nimDestroyRange', 'getCurrentException', 'getCurrentExceptionMsg', 'onRaise',
+  'likely', 'unlikely', 'rawProc', 'rawEnv', 'finished', 'slurp', 'staticRead',
+  'gorge', 'staticExec', 'rand', 'astToStr', 'InstatiationInfo', 'raiseAssert',
+  'shallow', 'compiles', 'safeAdd', 'locals',
+  -- Iterators.
+  'countdown', 'countup', 'items', 'pairs', 'fields', 'fieldPairs', 'lines',
+  -- Templates.
+  'accumulateResult', 'newException', 'CurrentSourcePath', 'assert', 'doAssert',
+  'onFailedAssert', 'eval',
+  -- Threads.
+  'running', 'joinThread', 'joinThreads', 'createThread', 'threadId',
+  'myThreadId',
+  -- Channels.
+  'send', 'recv', 'peek', 'ready'
+}, nil, true))
+
+-- Types.
+local type = token(l.TYPE , word_match({
+  'int', 'int8', 'int16', 'int32', 'int64', 'uint', 'uint8', 'uint16', 'uint32',
+  'uint64', 'float', 'float32', 'float64', 'bool', 'char', 'string', 'cstring',
+  'pointer', 'Ordinal', 'auto', 'any', 'TSignedInt', 'TUnsignedInt', 'TInteger',
+  'TOrdinal', 'TReal', 'TNumber', 'range', 'array', 'openarray', 'varargs',
+  'seq', 'set', 'TSlice', 'TThread', 'TChannel',
+  -- Meta Types.
+  'expr', 'stmt', 'typeDesc', 'void',
+}, nil, true))
+
+-- Constants.
+local constant = token(l.CONSTANT, word_match{
+  'on', 'off', 'isMainModule', 'CompileDate', 'CompileTime', 'NimVersion',
+  'NimMajor', 'NimMinor', 'NimPatch', 'cpuEndian', 'hostOS', 'hostCPU',
+  'appType', 'QuitSuccess', 'QuitFailure', 'inf', 'neginf', 'nan'
+})
+
+-- Identifiers.
+local identifier = token(l.IDENTIFIER, l.word)
+
+-- Operators.
+local operator = token(l.OPERATOR, S('=+-*/<>@$~&%|!?^.:\\`()[]{},;'))
+
+M._rules = {
+  {'whitespace', ws},
+  {'keyword', keyword},
+  {'function', func},
+  {'type', type},
+  {'constant', constant},
+  {'identifier', identifier},
+  {'comment', comment},
+  {'string', string},
+  {'number', number},
+  {'operator', operator},
+}
+
+M._FOLDBYINDENTATION = true
+
+return M