[Dev-luatex] Module searching

[Heiko Oberdiek]

On Tue, Dec 11, 2007 at 10:25:57AM +0100, Hans Hagen wrote:

> Heiko Oberdiek wrote:
> 
> > Reimplementing kpse library in Lua with analyzing texmf.cnf
> > files, path expansion, ls-R lookup, ...?
> 
> in this case i was more thinking of looking in the paths reported by 
> kpse (given that the path variable can be expanded), so, no lookup, but 
> looling at the file system; another option is that you just put the file 
> alongside the tex file, lookup the tex file, replace the suffix and load 
> the file; personally i see no need to put lua files that belong to tex 
> in the scripts path;

That is not the ide behind TDS. File searching in large trees
is expensive. Thus the directory structure of TDS differentiates
between file types to reduce the search space.

> > The other file types are covered: TeX files, tfm files, type 1 files, ...
> > Missing is a proper support for lua scripts.
> 
> lua scripts as such are like perl, ruby, whatever scripts; the 
> texmfscript path is not for tex related (runtime embedded or whatever) 
> scripts ... makes packaging a mess when we get a duplicate tree there, 
> apart from clashes

A TeX distribution could precompile lua scripts and put them
in a definite place, e.g.
  TDS:scripts/lua-compiled//
(eventually adding a os component, afaik precompiled scripts
aren't portable).

Then texmf.cnf could contain:
  TEXMFSCRIPTS.lua = $TEXMF/scripts/lua-compiled//:$TEXMF/scripts//

Then as first component only contains compiled lua files, few
files, compared to all files below TDS:/scripts// or even
TDS:tex//.

Also not all Lua scripts must depend on LuaTeX. There could be
standalone variants, libraries for stuff not directly related to TeX.

> a solution indeed, but as said ... i wonder if texmfscripts is meant for 
> that [...]

Using TDS:tex// you will have the same problem, if a module wants
to have path components. At least TDS has stricter unique constraints
below TDS:tex//. Two packages of the same format must not share
same file names.

Yours sincerely
  Heiko <oberdiek at uni-freiburg.de>