Modul:Str

  local Str = {} 

    function Str.len(frame)
      return mw.ustring.len(frame.args[1])
    end

    function Str.left(frame)
      local idx = tonumber(frame.args[2])
      if (not idx) or idx < 1 then
        return ""
      end
      return mw.ustring.sub(frame.args[1],1,idx)
    end

    function Str.right(frame)
      local laenge = tonumber(frame.args[2])
      if (not laenge) or laenge < 1 then
        return ""
      else
      laenge = - laenge
      end
      return mw.ustring.sub(frame.args[1],laenge,-1)
    end

    function Str.index(frame)
      local idx = tonumber(frame.args[2])
      if (not idx) or idx < 1 then
        return ""
      end
      return mw.ustring.sub(frame.args[1],idx,idx)
    end

    function Str.sub(frame)
      local von = tonumber(frame.args[2])
      local laenge = tonumber(frame.args[3])
      if (not von) or (not laenge) then
        return ""
      end
      if (von < 1) then
        von = 1
      end      
      local bis = von + laenge - 1
      if (bis < von) then
        return ""
      end
      return mw.ustring.sub(frame.args[1],von,bis)
    end

    function Str.crop(frame)
      local s = frame.args[1]
      local cut = tonumber(frame.args[2])
      local laenge =  mw.ustring.len(s)
      if (not cut) or (cut < 1) then
        return s
      end
      return mw.ustring.sub(s,1,laenge - cut)
    end

    function Str.cropleft(frame)
      local s = frame.args[1]
      local cut = tonumber(frame.args[2])
      local laenge =  mw.ustring.len(s)
      if (not cut) or (cut < 1) then
        return s
      end
      return mw.ustring.sub(s,cut+1,-1)
    end

    function Str.find(frame)
      if not frame.args[2] or frame.args[2] == "" then
        return 1
      end
      local  idx = mw.ustring.find(frame.args[1], frame.args[2],1, true)
      if idx then
          return idx
      else
          return -1
      end
    end

    function Str.hex2dez(frame)
      a = tonumber(frame.args[1],16)
      if a then
        return a
      else
        return 0
      end
    end

    function Str.match(frame)
        local text = frame.args[1] or ""
        local pattern = frame.args[2] or ""
        local index = tonumber(frame.args[3]) or 0
        if (text == "" or pattern == "") then return "" end
 
        -- return all captures (denoted by brackets in the pattern) if index is zero, otherwise return only the index-th capture
        if index <= 0 then
            return mw.ustring.match(text, pattern)
        else
            return ({mw.ustring.match(text, pattern)})[index]
        end
    end

function escape_lua_regex(str)
	return mw.ustring.gsub(str, ".", {
	    ["%"] = "%%";
	    ["^"] = "%^";
	    ["$"] = "%$";
	    ["."] = "%.";
	    ["("] = "%(";
	    [")"] = "%)";
	    ["["] = "%[";
	    ["]"] = "%]";
	    ["?"] = "%?";
	    ["*"] = "%*";
	    ["+"] = "%+";
	    ["-"] = "%-";
	    ["\0"] = "%z";
  	})
end
 
function Str.replace(frame)	
	local text = frame.args[1] or ""      -- Text, der bearbeitet werden soll
	local search = frame.args[2] or ""    -- Textstellen innerhalb von "text" die ersetzt werden sollen
	if text == "" or search == "" then return "" end 
 
	local replace = frame.args[3] or ""   -- Ersetzungstext
	local count = tonumber(frame.args[4]) -- Anzahl der Ersetzungen (optional)
	local regexsearch = frame.args[5]     -- beliebiger Wert um dafür zu sorgen, dass der Suchtext "search" als Lua-regulärer Ausdruck behandelt werden soll
 
	if not regexsearch or regexsearch == "" then
		search = escape_lua_regex(search)
		replace = mw.ustring.gsub(replace, "%%", "%%%%")
	end
 
	local result
	if count then
		result,_ = mw.ustring.gsub(text, search, replace, count)
	else
		result,_ = mw.ustring.gsub(text, search, replace)
	end
	return result
end

	-- richtet Zahlen numerisch aus
	function Str.adjustnumber(frame)
		local ausgabe;
		local text  = frame.args[1] or ""      -- Text, der bearbeitet werden soll, i.d.R. eine Dezimalzahl
		local i_li = math.floor(tonumber(frame.args[2])) or 2;     -- maximale Stellen links vom Trennzeichen
		local i_re = math.floor(tonumber(frame.args[3])) or 2;    -- maximale Stellen rechts vom Trennzeichen
		local sign  = frame.args['Z'] or ","   -- Trennzeichen
		local zeroes='00000000000000000000';   -- 20 duerften ausreichen.
		local zpos = 0;
		local len =  mw.ustring.len(text);
		if not text  or sign == "" then
			zpos = len + 1;
		else
			zpos = mw.ustring.find(text, sign,1, true) or len;
		end

		local zl = 0;
		local zr = 0;
		local t_li = "";
		local t_re = "";
		local z_li ="";
		local z_re ="";

		if zpos > 1 then 
			t_li = mw.ustring.sub(text,1, zpos-1);
		else
			t_li="";
		end

		if len-zpos > 0 then 
			t_re = mw.ustring.sub(text,zpos+1,-1);
		else
			t_re="";
		end

		zl = i_li -  mw.ustring.len(t_li);
		if zl < 1 then
			zl = 0;
			z_li = "";
		else
			z_li = '<span style="visibility:hidden;">' .. mw.ustring.sub(zeroes,1,zl) .. '</span>';
		end

		zr = i_re -  mw.ustring.len(t_re);
		if zr < 1 then
			zr = 0;
			z_re ="";
		else
			z_re ='<span style="visibility:hidden;">' ..  mw.ustring.sub(zeroes,1,zr) .. '</span>';
		end
		ausgabe = z_li .. t_li  .. sign .. t_re .. z_re;
		return ausgabe;
	end
 return Str