[NTG-context] Tabulator in database file not passed to Lua

23 Jan 2014

      Dear list,

I use the database module to load the lines of a file with some
data.  The lines are then separated with a lua script.  I use lua,
because I need to do some other things with the data (rounding
numbers, combining some fields etc.)  Please consider the following
minimal working example:

\usemodule[database]
\defineseparatedlist [Data]
[
	before=,
	after=,
	separator={},
	commentchar=\letterpercent,
	command=\Tabrow,
]

\startluacode
function explode(sep,str)
if (sep=="") then return false end
  local pos,arr = 0,{}
  -- for each separator found
  for st,sp in function() return string.find(str,sep,pos,true) end do
    -- Attach chars left of current separator 
    table.insert(arr,string.sub(str,pos,st-1))
    -- Jump past current separator
    pos = sp + 1
  end
  -- Attach chars right of last separator
  table.insert(arr,string.sub(str,pos))
return arr
end

function tabrow(fileline)
	local tabarray = explode(";",fileline)
	local tabline = ""
	for index,value in ipairs(tabarray) do
		tabline = tabline .. " / " .. value
	end
	return tabline
end
\stopluacode

\define[1]\Tabrow{\ctxlua{context(tabrow("#1"))}}

\starttext
\processseparatedfile[Data][Test.dat]
\stoptext

This is the content of the file Test.dat:
Eins;zwei;drei;vier

Of course the line separation could be done easier with the database
module.  However, I thought this way I could use the tabulator as the
separator in my file.  But when I change the separator from ";" to
"\\t", it doesn't work.  I suppose this is because the tabulators are
passed to Lua as spaces.  Or is "\\t" the wrong code?  Would it be
possible to use tabulators as separators, if I load the file with lua
and not with the database module?

Kind regards,
Joshua Krämer