vis: experimental support for lua/lpeg based syntax highlighting

The lua based lexers are searched in the following order:

 $VIS_PATH/lexers
 $HOME/.vis/lexers
 /usr/share/vis/lexers

followed by the standard lua package.path

4 files changed, 184 insertions, 5 deletions

diff --git a/lexers/diff.lua b/lexers/diff.lua
index 53b7f17..ee680aa 100644
--- a/lexers/diff.lua
+++ b/lexers/diff.lua
@@ -34,9 +34,9 @@ M._rules = {
 
 M._tokenstyles = {
   header = l.STYLE_COMMENT,
-  addition = 'fore:$(color.green)',
-  deletion = 'fore:$(color.red)',
-  change = 'fore:$(color.yellow)'
+  addition = 'fore:'..l.colors.green,
+  deletion = 'fore:'..l.colors.red,
+  change = 'fore:'..l.colors.yellow,
 }
 
 M._LEXBYLINE = true
diff --git a/lexers/lexer.lua b/lexers/lexer.lua
index 0dc9674..4d7eb60 100644
--- a/lexers/lexer.lua
+++ b/lexers/lexer.lua
@@ -974,7 +974,10 @@ local default = {
   'function', 'class', 'type', 'label', 'regex', 'embedded'
 }
 for _, v in ipairs(default) do
-  M[string_upper(v)], M['STYLE_'..string_upper(v)] = v, '$(style.'..v..')'
+  M[string_upper(v)] = v
+  if not M['STYLE_'..string_upper(v)] then
+    M['STYLE_'..string_upper(v)] = ''
+  end
 end
 -- Predefined styles.
 local predefined = {
@@ -982,7 +985,10 @@ local predefined = {
   'indentguide', 'calltip'
 }
 for _, v in ipairs(predefined) do
-  M[string_upper(v)], M['STYLE_'..string_upper(v)] = v, '$(style.'..v..')'
+  M[string_upper(v)] = v
+  if not M['STYLE_'..string_upper(v)] then
+    M['STYLE_'..string_upper(v)] = ''
+  end
 end
 
 ---
@@ -1584,4 +1590,122 @@ M.property_expanded = setmetatable({}, {
 local lexer
 ]]
 
+function M.get_style(lexer, lang, token_name)
+  return lexer['STYLE_'..string_upper(token_name)] or lang._EXTRASTYLES[token_name]
+end
+
+local files = {
+	[".as|.asc"] = "actionscript",
+	[".adb|.ads"] = "ada",
+	[".g|.g4"] = "antlr",
+	[".ans|.inp|.mac"] = "apdl",
+	[".applescript"] = "applescript",
+	[".asm|.ASM|.s|.S"] = "asm",
+	[".asa|.asp|.hta"] = "asp",
+	[".awk"] = "awk",
+	[".bat|.cmd"] = "batch",
+	[".bib"] = "bibtex",
+	[".boo"] = "boo",
+	[".cs"] = "csharp",
+	[".c|.cc|.C"] = "ansi_c",
+	[".cpp|.cxx|.c++|.h|.hh|.hpp|.hxx|.h++"] = "cpp",
+	[".ck"] = "chuck",
+	[".cmake|.cmake.in|.ctest|.ctest.in"] = "cmake",
+	[".coffee"] = "coffeescript",
+	[".css"] = "css",
+	[".cu|.cuh"] = "cuda",
+	[".d|.di"] = "dmd",
+	[".dart"] = "dart",
+	[".desktop"] = "desktop",
+	[".diff|.patch"] = "diff",
+	[".dot"] = "dot",
+	[".e|.eif"] = "eiffel",
+	[".ex|.exs"] = "elixir",
+	[".erl|.hrl"] = "erlang",
+	[".fs"] = "fsharp",
+	[".fish"] = "fish",
+	[".forth|.frt|.fs"] = "forth",
+	[".f|.for|.ftn|.fpp|.f77|.f90|.f95|.f03|.f08"] = "fortran",
+	[".g|.gd|.gi|.gap"] = "gap",
+	[".po|.pot"] = "gettext",
+	[".glslf|.glslv"] = "glsl",
+	[".dem|.plt"] = "gnuplot",
+	[".go"] = "go",
+	[".groovy|.gvy"] = "groovy",
+	[".gtkrc"] = "gtkrc",
+	[".hs"] = "haskell",
+	[".htm|.html|.shtm|.shtml|.xhtml"] = "html",
+	[".idl|.odl"] = "idl",
+	[".inf|.ni"] = "inform",
+	[".cfg|.cnf|.inf|.ini|.reg"] = "ini",
+	[".io"] = "io_lang",
+	[".bsh|.java"] = "java",
+	[".js|.jsfl"] = "javascript",
+	[".json"] = "json",
+	[".jsp"] = "jsp",
+	[".bbl|.dtx|.ins|.ltx|.tex|.sty"] = "latex",
+	[".less"] = "less",
+	[".lily|.ly"] = "lilypond",
+	[".cl|.el|.lisp|.lsp"] = "lisp",
+	[".litcoffee"] = "litcoffee",
+	[".lua"] = "lua",
+	["GNUmakefile|.iface|.mak|.mk|makefile|Makefile"] = "makefile",
+	[".md"] = "markdown",
+	[".n"] = "nemerle",
+	[".nim"] = "nim",
+	[".nsh|.nsi|.nsis"] = "nsis",
+	[".m|.mm|.objc"] = "objective_c",
+	[".caml|.ml|.mli|.mll|.mly"] = "caml",
+	[".dpk|.dpr|.p|.pas"] = "pascal",
+	[".al|.perl|.pl|.pm|.pod"] = "perl",
+	[".inc|.php|.php3|.php4|.phtml"] = "php",
+	[".pike|.pmod"] = "pike",
+	[".PKGBUILD"] = "pkgbuild",
+	[".ps1"] = "powershell",
+	[".eps|.ps"] = "ps",
+	[".prolog"] = "prolog",
+	[".props|.properties"] = "props",
+	[".sc|.py|.pyw"] = "python",
+	[".R|.Rout|.Rhistory|.Rt|Rout.save|Rout.fail"] = "rstats",
+	[".r|.reb"] = "rebol",
+	[".rst"] = "rest",
+	[".orx|.rex"] = "rexx",
+	[".erb|.rhtml"] = "rhtml",
+	[".Rakefile|.rake|.rb|.rbw"] = "ruby",
+	[".rs"] = "rust",
+	[".sass|.scss"] = "sass",
+	[".scala"] = "scala",
+	[".sch|.scm"] = "scheme",
+	[".bash|.bashrc|.bash_profile|.configure|.csh|.sh|.zsh"] = "bash",
+	[".changes|.st|.sources"] = "smalltalk",
+	[".ddl|.sql"] = "sql",
+	[".tcl|.tk"] = "tcl",
+	[".texi"] = "texinfo",
+	[".toml"] = "toml",
+	[".vala"] = "vala",
+	[".vcf|.vcard"] = "vcard",
+	[".v|.ver"] = "verilog",
+	[".vh|.vhd|.vhdl"] = "vhdl",
+	[".asa|.bas|.cls|.ctl|.dob|.dsm|.dsr|.frm|.pag|.vb|.vba|.vbs"] = "vb",
+	[".wsf"] = "wsf",
+	[".dtd|.svg|.xml|.xsd|.xsl|.xslt|.xul"] = "xml",
+	[".xtend"] = "xtend",
+	[".yaml"] = "yaml",
+}
+
+function M.lexer_name(filename)
+	-- filename = string.lower(filename)
+	for patterns, lang in pairs(files) do
+		for pattern in string.gmatch(patterns, '[^|]+') do
+			if #filename >= #pattern then
+				local s, e = string.find(filename, pattern, -#pattern, true)
+				if s ~= e and e == #filename then
+					return lang
+				end
+			end
+		end
+	end
+	return nil
+end
+
 return M
diff --git a/lexers/themes/default.lua b/lexers/themes/default.lua
new file mode 120000
index 0000000..8479b1b
--- /dev/null
+++ b/lexers/themes/default.lua
@@ -0,0 +1 @@
+solarized.lua
\ No newline at end of file
diff --git a/lexers/themes/solarized.lua b/lexers/themes/solarized.lua
new file mode 100644
index 0000000..0575056
--- /dev/null
+++ b/lexers/themes/solarized.lua
@@ -0,0 +1,54 @@
+-- Solarized color codes Copyright (c) 2011 Ethan Schoonover
+local colors = {
+	['base03'] = '#002b36',
+	['base02'] = '#073642',
+	['base01'] = '#586e75',
+	['base00'] = '#657b83',
+	['base0']  = '#839496',
+	['base1'] = '#93a1a1',
+	['base2'] = '#eee8d5',
+	['base3'] = '#fdf6e3',
+	['yellow'] = '#b58900',
+	['orange'] = '#cb4b16',
+	['red'] = '#dc322f',
+	['magenta'] = '#d33682',
+	['violet'] = '#6c71c4',
+	['blue'] = '#268bd2',
+	['cyan'] = '#2aa198',
+	['green'] = '#859900',
+} 
+
+lexers.colors = colors
+-- dark
+local fg = ',fore:'..colors.base0..','
+local bg = ',back:'..colors.base03..','
+-- light
+-- local fg = ',fore:'..colors.base03..','
+-- local bg = ',back:'..colors.base3..','
+
+lexers.STYLE_DEFAULT = bg..fg
+lexers.STYLE_NOTHING = bg
+lexers.STYLE_CLASS = 'fore:yellow'
+lexers.STYLE_COMMENT = 'fore:'..colors.base01
+lexers.STYLE_CONSTANT = 'fore:'..colors.cyan
+lexers.STYLE_DEFINITION = 'fore:'..colors.blue
+lexers.STYLE_ERROR = 'fore:'..colors.red..',italics'
+lexers.STYLE_FUNCTION = 'fore:'..colors.blue
+lexers.STYLE_KEYWORD = 'fore:'..colors.green
+lexers.STYLE_LABEL = 'fore:'..colors.green
+lexers.STYLE_NUMBER = 'fore:'..colors.cyan
+lexers.STYLE_OPERATOR = 'fore:'..colors.green
+lexers.STYLE_REGEX = 'fore:green'
+lexers.STYLE_STRING = 'fore:'..colors.cyan
+lexers.STYLE_PREPROCESSOR = 'fore:'..colors.orange
+lexers.STYLE_TAG = 'fore:'..colors.red
+lexers.STYLE_TYPE = 'fore:'..colors.yellow
+lexers.STYLE_VARIABLE = 'fore:'..colors.blue
+lexers.STYLE_WHITESPACE = ''
+lexers.STYLE_EMBEDDED = 'back:blue'
+lexers.STYLE_IDENTIFIER = fg
+
+lexers.STYLE_LINENUMBER = fg
+lexers.STYLE_CURSOR = 'fore:'..colors.base03..',back:'..colors.base0
+-- lexers.STYLE_SELECTION = 'back:'..colors.base02
+lexers.STYLE_SELECTION = 'back:white'