$Id$

Rough plan for initial prototype RE.

1) Hack quick cert generator [done]

2) Hack xml-parse-test into something that can:

 - Generate XML (just compose directly, probably)
 - Encode XML in CMS using specified signing key and certs
 - Write that to a destination file

 - Pick up signed CMS from from a file
 - Check CMS signatures and extract XML
 - Validate (xmllint --relaxng) the XML
 - Decode (xml.sax) the XML and dump the result

 Log everything as we go.
 data structures.

Schema is RNC (RelaxNG Compact) syntax, xmllint wants RNG (RelaxNG
XML) syntax, so use /usr/ports/textproc/trang to convert:

    $ trang foo.rnc foo.rng

3) Whack (2) into something that does this over minimal HTTP.

4) [to be continued...]



Fun with SQL.  Tim has given me a nice SQL schema for the objects we
worked out in Prague (superset of left-right protocol).  Still
debugging that design, but broad outlines are clear.

Some question how to deal with in-memory data and SQL without going
mad.  Am assuming RE is event driven.  Current theory: pull in an
entire context (one row of the "self" table and everything that links
to that self_id), run this event with it, save out any changes before
this event terminates.  Perhaps keep an LRU cache of the last few such
contexts in which we've run, to save loading every time (eg, receipt
of an answer to an up-down or left-right protocol query is a discrete
event, would be annoying to have to read everything back from SQL
again).

If we can work out a tree that spans one such memory context (almost
there), we can just walk that tree to handle pretty much all SQL.

Basic data structures we need for every object we're going to store in
SQL:

- Object type to hold the object (duh).

- List of children in the data structure tree.

- SQL SELECT expression (including variable bindings!) to pull all
  rows matching blah blah out of SQL.  Tricky bit here is variable
  bindings, as otherwise the obvious handling would be a simple
  method.  Various possible ways to hack this in Python, perhaps just

     lambda(x,y,z): """SQL blah blah""" % dict

  Or perhaps this meta-tree is itself built from a Python class
  (probably should be) and these lambdas turn into methods of the
  meta-tree.  Or something.

- SQL to INSERT ...

- SQL to UPDATE ...

- SQL to DROP ...