colorize verbatims

colorVerb.lua

luatexbase.provides_module({
  name        = 'colorVerb',
  date        = '2011/01/20',
  version     = 0.1,
  description = 'Colorize Commands/Braces/Brackets in Verbatim',
  author      = 'Dohyun Kim',
  license     = 'Public Domain',
})

colorVerb = colorVerb or {}
local colorVerb = colorVerb

local colors = {
  cscolor      = {0,    0.5,  0.5},
  bracecolor   = {0.9,  0,    0  },
  bracketcolor = {0.9,  0,    0  },
  parencolor   = {0.9,  0,    0  },
  commentcolor = {0.5,  0.5,  0.5},
  operatecolor = {0.5,  0.5,  0  },
}
colorVerb.colors = colors

local cscolor       = colors.cscolor
local bracecolor    = colors.bracecolor
local bracketcolor  = colors.bracketcolor
local parencolor    = colors.parencolor
local commentcolor  = colors.commentcolor
local operatecolor  = colors.operatecolor

local attrVerb      = luatexbase.attributes.attrVerb
local glyph         = node.id("glyph")
local hlist         = node.id("hlist")
local vlist         = node.id("vlist")
local kern          = node.id("kern")
local nodecopy      = node.copy
local nodetail      = node.tail
local has_attr      = node.has_attribute
local insert_before = node.insert_before
local insert_after  = node.insert_after
local stringchar    = unicode.utf8.char
local concat        = table.concat
local addtocallback = luatexbase.add_to_callback
local colorpush     = node.new("whatsit", "pdf_colorstack")
colorpush.stack     = 0
colorpush.command   = 1
local colorpop      = nodecopy(colorpush)
colorpop.command    = 2

local parenchars = {
  ["("] = parencolor,
  [")"] = parencolor,
  ["{"] = bracecolor,
  ["}"] = bracecolor,
  ["["] = bracketcolor,
  ["]"] = bracketcolor,
  ["&"] = operatecolor,
}

local keywords = {
  { }, -- TeX --
  {    -- Lua --
    ["and"]       = operatecolor,
    ["break"]     = cscolor,
    ["do"]        = operatecolor,
    ["else"]      = operatecolor,
    ["elseif"]    = operatecolor,
    ["end"]       = operatecolor,
    ["error"]     = cscolor,
    ["false"]     = {1, 0, 0},
    ["for"]       = operatecolor,
    ["function"]  = cscolor,
    ["if"]        = operatecolor,
    ["in"]        = operatecolor,
    ["ipairs"]    = cscolor,
    ["local"]     = operatecolor,
    ["next"]      = cscolor,
    ["nil"]       = {1, 0, 0},
    ["not"]       = operatecolor,
    ["or"]        = operatecolor,
    ["pairs"]     = cscolor,
    ["require"]   = cscolor,
    ["return"]    = cscolor,
    ["then"]      = operatecolor,
    ["tonumber"]  = cscolor,
    ["tostring"]  = cscolor,
    ["true"]      = {1, 0, 0},
    ["type"]      = cscolor,
    ["while"]     = operatecolor,
  },
  { -- MetaPost --
    ["beginfig"]          = cscolor,
    ["btex"]              = cscolor,
    ["buildcycle"]        = cscolor,
    ["color"]             = operatecolor,
    ["cosd"]              = cscolor,
    ["cycle"]             = operatecolor,
    ["dashed"]            = operatecolor,
    ["decimal"]           = cscolor,
    ["def"]               = operatecolor,
    ["dir"]               = cscolor,
    ["dotlabel"]          = cscolor,
    ["draw"]              = cscolor,
    ["drawarrow"]         = cscolor,
    ["drawoptions"]       = cscolor,
    ["else"]              = operatecolor,
    ["elseif"]            = operatecolor,
    ["enddef"]            = operatecolor,
    ["endfig"]            = cscolor,
    ["endfor"]            = operatecolor,
    ["etex"]              = cscolor,
    ["expr"]              = operatecolor,
    ["fi"]                = operatecolor,
    ["fill"]              = cscolor,
    ["for"]               = operatecolor,
    ["if"]                = operatecolor,
    ["intersectionpoint"] = operatecolor,
    ["label"]             = cscolor,
    ["pair"]              = operatecolor,
    ["path"]              = operatecolor,
    ["picture"]           = operatecolor,
    ["scaled"]            = operatecolor,
    ["sind"]              = cscolor,
    ["shifted"]           = operatecolor,
    ["sqrt"]              = cscolor,
    ["thelabel"]          = cscolor,
    ["unfill"]            = cscolor,
    ["uniformdeviate"]    = cscolor,
    ["upto"]              = operatecolor,
    ["vardef"]            = operatecolor,
    ["withcolor"]         = operatecolor,
    ["xpart"]             = cscolor,
    ["ypart"]             = cscolor,
  },
}

local function do_colorize(head, start, stop, color)
  local colorstart = nodecopy(colorpush)
  local colorstop  = nodecopy(colorpop)
  color = concat(color," ")
  colorstart.data = color:find(" rg") and color or color.." rg"
  head = insert_before(head, start, colorstart)
  head, colorstop = insert_after (head, stop, colorstop)
  return head, colorstop
end

local function do_color_Verb (head)
  local curr = head
  while curr do
    local id = curr.id
    if id == hlist or id == vlist then
      curr.head = do_color_Verb(curr.head)
    elseif id == glyph then
      local attr = has_attr(curr, attrVerb)
      -- attrVerb == 1 : TeX
      -- attrVerb == 2 : Lua
      -- attrVerb == 3 : MetaPost
      if attr then
        local chr = stringchar(curr.char)
        if attr ~= 1 and chr == "\"" or chr == "\'" then
          local nn = curr.next
          while nn do
            curr = nn
            if nn.id == glyph then
              local thischr = stringchar(nn.char)
              if thischr == "\\" then
                nn = nn.next
                if not nn then break end
              elseif thischr == chr then
                break
              end
            end
            nn = nn.next
          end
        elseif chr == "\\" then
          local nn = curr.next
          local startnode, stopnode = curr, nn
          while nn and nn.id == glyph and stringchar(nn.char):find("%a") do
            stopnode = nn
            nn = nn.next
          end
          if stopnode then
            head, curr = do_colorize(head, startnode, stopnode, cscolor)
          end
        elseif attr ~= 1 and chr:find("[%a%._]") then
          local startnode, t = curr, { chr }
          local nn = curr.next
          while nn and nn.id == glyph do
            local chr = stringchar(nn.char)
            if chr:find("[%a%._]") then
              t[#t + 1] = chr
              curr = nn
              nn = nn.next
            else
              break
            end
          end
          local color = keywords[attr][concat(t)]
          if color then
            head, curr = do_colorize(head, startnode, curr, color)
          end
        elseif parenchars[chr] then
          head, curr = do_colorize(head, curr, curr, parenchars[chr])
        elseif chr == "%" and attr ~= 2 then -- TeX, MetaPost comment
          return do_colorize(head, curr, nodetail(curr), commentcolor)
        elseif chr == "-" and attr == 2 then -- Lua comment; box comment is not supported
          local nn = curr.next
          if nn.id == kern and nn.kern == 0 then
            local nn = nn.next
            if nn.id == glyph and stringchar(nn.char) == chr then
              return do_colorize(head, curr, nodetail(curr), commentcolor)
            end
          end
        end
      end
    end
    curr = curr.next
  end
  return head
end

addtocallback("pre_output_filter", do_color_Verb, "colorVerb.pre_output")

colorVerb.sty

% written by Dohyun Kim
% Public Domain

\ProvidesPackage{colorVerb}
  [2011/01/20 v0.1 Color Commands/Braces/Brackets in Verbatim]

\ifx\directlua\undefined
  \let\usecolorVerb\relax
  \let\usecolorLua\relax
  \let\usecolorMP\relax
  \def\colorVerbextractcolor#1 to #2{}
\endinput\fi

\newluatexattribute\attrVerb
\def\usecolorVerb{\attrVerb\@ne}
\def\usecolorLua {\attrVerb\tw@}
\def\usecolorMP  {\attrVerb\thr@@}

\RequireLuaModule{colorVerb}

\def\cscolor     #1{\directlua{ colorVerb.colors.cscolor      = {"#1"} }}
\def\bracecolor  #1{\directlua{ colorVerb.colors.bracecolor   = {"#1"} }}
\def\bracketcolor#1{\directlua{ colorVerb.colors.bracketcolor = {"#1"} }}
\def\parencolor  #1{\directlua{ colorVerb.colors.parencolor   = {"#1"} }}
\def\commentcolor#1{\directlua{ colorVerb.colors.commentcolor = {"#1"} }}

%%% extract color defined with xcolor.sty
%   eg. \colorVerbextractcolor{green!45!blue} to \cscolor
\def\colorVerbextractcolor#1 to #2{%
  \begingroup
  \def\set@color{#2{\current@color}}%
  \color{#1}%
  \endgroup
}