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, 91 insertions, 0 deletions

diff --git a/lua/lexers/fortran.lua b/lua/lexers/fortran.lua
new file mode 100644
index 0000000..2a1fe97
--- /dev/null
+++ b/lua/lexers/fortran.lua
@@ -0,0 +1,91 @@
+-- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
+-- Fortran 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 = 'fortran'}
+
+-- Whitespace.
+local ws = token(l.WHITESPACE, l.space^1)
+
+-- Comments.
+local c_comment = l.starts_line(S('Cc')) * l.nonnewline^0
+local d_comment = l.starts_line(S('Dd')) * l.nonnewline^0
+local ex_comment = l.starts_line('!') * l.nonnewline^0
+local ast_comment = l.starts_line('*') * l.nonnewline^0
+local line_comment = '!' * l.nonnewline^0
+local comment = token(l.COMMENT, c_comment + d_comment + ex_comment +
+                      ast_comment + line_comment)
+
+-- Strings.
+local sq_str = l.delimited_range("'", true, true)
+local dq_str = l.delimited_range('"', true, true)
+local string = token(l.STRING, sq_str + dq_str)
+
+-- Numbers.
+local number = token(l.NUMBER, (l.float + l.integer) * -l.alpha)
+
+-- Keywords.
+local keyword = token(l.KEYWORD, word_match({
+  'include', 'program', 'module', 'subroutine', 'function', 'contains', 'use',
+  'call', 'return',
+  -- Statements.
+  'case', 'select', 'default', 'continue', 'cycle', 'do', 'while', 'else', 'if',
+  'elseif', 'then', 'elsewhere', 'end', 'endif', 'enddo', 'forall', 'where',
+  'exit', 'goto', 'pause', 'stop',
+  -- Operators.
+  '.not.', '.and.', '.or.', '.xor.', '.eqv.', '.neqv.', '.eq.', '.ne.', '.gt.',
+  '.ge.', '.lt.', '.le.',
+  -- Logical.
+  '.false.', '.true.'
+}, '.', true))
+
+-- Functions.
+local func = token(l.FUNCTION, word_match({
+  -- I/O.
+  'backspace', 'close', 'endfile', 'inquire', 'open', 'print', 'read', 'rewind',
+  'write', 'format',
+  -- Type conversion, utility, and math.
+  'aimag', 'aint', 'amax0', 'amin0', 'anint', 'ceiling', 'cmplx', 'conjg',
+  'dble', 'dcmplx', 'dfloat', 'dim', 'dprod', 'float', 'floor', 'ifix', 'imag',
+  'int', 'logical', 'modulo', 'nint', 'real', 'sign', 'sngl', 'transfer',
+  'zext', 'abs', 'acos', 'aimag', 'aint', 'alog', 'alog10', 'amax0', 'amax1',
+  'amin0', 'amin1', 'amod', 'anint', 'asin', 'atan', 'atan2', 'cabs', 'ccos',
+  'char', 'clog', 'cmplx', 'conjg', 'cos', 'cosh', 'csin', 'csqrt', 'dabs',
+  'dacos', 'dasin', 'datan', 'datan2', 'dble', 'dcos', 'dcosh', 'ddim', 'dexp',
+  'dim', 'dint', 'dlog', 'dlog10', 'dmax1', 'dmin1', 'dmod', 'dnint', 'dprod',
+  'dreal', 'dsign', 'dsin', 'dsinh', 'dsqrt', 'dtan', 'dtanh', 'exp', 'float',
+  'iabs', 'ichar', 'idim', 'idint', 'idnint', 'ifix', 'index', 'int', 'isign',
+  'len', 'lge', 'lgt', 'lle', 'llt', 'log', 'log10', 'max', 'max0', 'max1',
+  'min', 'min0', 'min1', 'mod', 'nint', 'real', 'sign', 'sin', 'sinh', 'sngl',
+  'sqrt', 'tan', 'tanh'
+}, nil, true))
+
+-- Types.
+local type = token(l.TYPE, word_match({
+  'implicit', 'explicit', 'none', 'data', 'parameter', 'allocate',
+  'allocatable', 'allocated', 'deallocate', 'integer', 'real', 'double',
+  'precision', 'complex', 'logical', 'character', 'dimension', 'kind',
+}, nil, true))
+
+-- Identifiers.
+local identifier = token(l.IDENTIFIER, l.alnum^1)
+
+-- Operators.
+local operator = token(l.OPERATOR, S('<>=&+-/*,()'))
+
+M._rules = {
+  {'whitespace', ws},
+  {'comment', comment},
+  {'keyword', keyword},
+  {'function', func},
+  {'type', type},
+  {'number', number},
+  {'identifier', identifier},
+  {'string', string},
+  {'operator', operator},
+}
+
+return M