[developers] [incr tsdb()] question

Stephan Oepen oe at ifi.uio.no
Mon Nov 12 09:10:44 CET 2007

hi emily,

> Is it already possible to combine the compare > detail
> function and the discrinimants to find the discrinimants
> which identify the parses in each subcolumn of derivation
> when "derivation" is part of the intersection?  I'm thinking
> of something like a button that takes you into the compare
> trees view, with the (g)old trees in one color, the shared
> trees in another, and the new trees in a third.  Then 
> you could play around with the discriminants to see what's
> allowing parses in one grammar but not another.   I think
> this would be an extremely useful grammar debugging aid.

yes, i see where you are headed.  the functionality you describe is not
currently available in [incr tsdb()].  it would be non-trivial to add,
as the discriminant tool is built on the assumption that it can rebuild
parse trees, using the grammar currently loaded into its host platform,
i.e. the LKB.  in the scenario you describe, part of these trees would
actually not rebuild with the current grammar.  so, to approximate what
you suggest one would have to build a variant of the discriminant tool:
one to not rebuild the derivations; in this mode, it will be impossible
to draw trees with abbreviatory category labels, but i believe it would
be possible to extract discriminants.

for larger sets of derivation differences this would not be useful, but 
are you aware of the double-click functionality on derivations?  as you
double-click on any of the red numbers (which indicate set cardinality)
in the `< = >' table, this will show the underlying set.  for the case 
of derivations, each derivation in the new window will again be red, so
you can double-click to either (a) have it rebuilt and its tree shown;
or (b) have [incr tsdb()] detect where rebuilding failed and print that
information to the console (typically the *common-lisp* buffer).

--- obviously this is not quite what you suggested, so feel free to add
to the [incr tsdb()] wish list page on the wiki.

                                                       all best  -  oe

+++ Universitetet i Oslo (IFI); Boks 1080 Blindern; 0316 Oslo; (+47) 2284 0125
+++     CSLI Stanford; Ventura Hall; Stanford, CA 94305; (+1 650) 723 0515
+++       --- oe at ifi.uio.no; oe at csli.stanford.edu; stephan at oepen.net ---

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