[developers] Whoa, missed someting, sorry

Ann Copestake Ann.Copestake at cl.cam.ac.uk
Fri Mar 21 13:50:17 CET 2008

kiefer at dfki.de said:
> as you may know, Yi Zhang has implemented a C++ version of the MRS code  that
> outputs the MRSs in XML format.

I wasn't aware of this - does it allow the same options as the Lisp code does?
(Unfortunately, as I recently became aware, the existing Lisp code no longer 
has the desired behaviour for some of the teaching grammars when used `out of 
the box'.)

kiefer at dfki.de said:
> Could the producers of MRS maybe  test this code by comparing the new outputs
> against their tree banks? I understood that there is some code out there to
> check the equality of  two MRSs.

you mean the grammar writers whose grammars produce MRSs?  I don't think that 
using the MRS equality checking code is the right thing in this context - I'd 
suggest looking for equivalence of the XML (modulo whitespace, but XML 
comparisons should ignore whitespace anyway).  The MRS comparison code that I 
know about is designed to check for various degrees of semantic equivalence, 
but to ignore difference such as order of EPs - however these matter for human 

kiefer at dfki.de said:
> And i have another question regarding the (R)MRS formats that are  produced
> by PET now: would it be possible to generate the other formats  from what is
> available in the XML format, especially for RMRS, or is  there something
> missing, which might eventually be added to the current  XML output? 

I think that the XML format for RMRS is complete.  I routinely store XML and 
use that as the reference format - RMRS was designed with this in mind from 
the start.  For MRS, the situation is not so straightforward, since the XML 
output was just something I put in for convenience.  One issue is the 
different treatments of sorts on the variables.  There is also information in 
the Lisp structures which is not preserved on output - I don't know whether 
any of it should be.  I hope we can make progress on agreeing what sensible 
options are for MRS fairly soon but I think there will be some further changes.

kiefer at dfki.de said:
> My hope behind this is that we can remove all ecl/lisp stuff from pet in  the
> (hopefully not so) long run because of all the problems that it  generates.

of course someone will then have to keep the C++ version of the MRS code in 
synch with the Lisp version

> And having one output format that can be transformed  externally or
> internally would simplify and modularize things further.



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