Note on maintenance 

2009-12-30

(This note is of interest only to the maintainer; it may safely be
ignored by others.)

Xerophily is dual-licensed uder the W3C license and the LGPL.  

We considered putting both licenses into the source and saying "user
gets to choose", but this seems to require complicated text about
whether the user has to preserve the right to choose the license for
later users in the chain, etc.  So we decided just to have two copies
of the source on the Web, one with the W3C license and one with the
LGPL.

When maintenance is performed, changes are made in the parent
directory, and then all files are copied down into this directory with
appropriate changes, thus:

  cd xsdl-regex

  # edit LGPL/temp.lgpl.asc to give it the right dates for the things
  # you've just changed ...

  for f in *.pl *.xsl re.xml README 
    do echo "$f ..."
       sed -f LGPL/changelicense.sed < $f > LGPL/$f
       echo "... $f"
  done

A couple of things have special status:

(1) The module license.pl defines a data structure for the W3C
license.  At one time the intent was to add calls to :- license(w3c)
to each source file; that no longer seems like a good idea, so the
code is not in fact used.  Since it's here, however, it will be copied
by the command given above, and it needs to be changed: its call to :-
license(w3c) should be changed to :- license(lgpl).

(2) The file lookahead.dcg.pl carries no W3C copyright notice and no
LGPL notice; this is intentional, because it's copied pretty much
directly from O'Keefe, Craft of Prolog.