[Attempto] Can't unparse expressions (from DRSXML) using atom_to_term/3, Single quotes lost

[Joshua TAYLOR]

Thanks for the quick response. I usually access APE via the
webservice, but I downloaded the 6.5 distribution and applied those
patches, and can parse sentences that gave me problems yesterday.

With regard to the quoting of strings, I don't think that /all/
strings need to be quoted---just matching the prolog output would be
fine.  It seems that the Prolog convention is to only quote those
strings that contain special characters. E.g, in

CL-USER 47 > (invoke-ape-webservice :text "\"ab\" is shorter than \"ab
c\"." :solo "drs")
"drs([A, B], [property(A, short, comp_than, string('ab c'))-1/5,
predicate(B, be, string(ab), A)-1/4])"

there are both string(ab) and string('ab c'). I'm not as familiar with
Prolog as with Lisp, but Lisp has a printing function which prints
Lisp-readable output. If Prolog has a similar printer, it's output
would probably suffice (modulo whatever XML entity encoding is
required).

Regards,
Joshua

On Tue, Jun 2, 2009 at 11:38 AM, Tobias Kuhn <t.kuhn at gmx.ch> wrote:
> Hi Joshua,
>
> I agree. Strings should be quoted in the XML representation of the DRS. It's
> no my todo list now and I will fix it as soon as possible.
>
> By the way, new versions of the files parser/grammar.fit and
> utils/drs_to_xml.pl are attached that should solve the problem with the XML
> output for sentences like "John likes Mary". (However, it's not yet
> systematically tested.)
>
>
> Tobias
>
>
> Joshua TAYLOR wrote:
>>
>> Hello,
>>
>> I'm having a bit of trouble unparsing expressions using
>> atom_to_term/3.  It seems that single quotes that are present in
>> Prolog output are lost in DRSXML output. For instance:
>>
>> === DRS output
>>
>> CL-USER 28 > (invoke-ape-webservice :text "\"a)b\" is good." :solo "drs")
>> "drs([A, B], [property(A, good, pos)-1/5, predicate(B, be,
>> string('a)b'), A)-1/4])"
>>
>> ?- atom_to_term("string('a)b')",X,Y).
>> X = string('a)b'),
>> Y = [].
>>
>> === DRSXML output
>>
>> <DRS domain=\"A B\">
>>  <property ref=\"A\" adj=\"good\" degree=\"pos\" sentid=\"1\"
>> tokid=\"5\"/>
>>  <predicate ref=\"B\" verb=\"be\" subj=\"string(a)b)\"
>>      obj=\"A\" sentid=\"1\" tokid=\"4\"/>
>> </DRS>"
>>
>> ?- atom_to_term("string(a)b)",X,Y).
>> ERROR: Syntax error: Operator expected
>> ERROR: string(a)
>> ERROR: ** here **
>> ERROR: b) .
>>
>> Now, I couldn't find anything that explicitly affirmed that the DRSXML
>> attribute values would be string representations of Prolog atoms, but
>> the representations seemed close enough that it was probably the case.
>>  If string contents aren't quoted, the expressions can easily become
>> ambiguous.  E.g., (a contrived example):
>>
>> CL-USER 33 > (invoke-ape-webservice :text "John dictates \"Every )
>> must be preceded by a (.\"." :solo "drsxml")
>> "<?xml version=\"1.0\" encoding=\"UTF-8\"?>
>>
>> <DRS domain=\"A\">
>>  <predicate
>>      ref=\"A\"
>>      verb=\"dictate\"
>>      subj=\"named(John)\"
>>      obj=\"string(Every ) must be preceded by a (.)\"
>>      sentid=\"1\"
>>      tokid=\"2\"/>
>> </DRS>"
>>
>> Regards,
>> Joshua
>> _______________________________________________
>> attempto mailing list
>> attempto at lists.ifi.uzh.ch
>> https://lists.ifi.uzh.ch/listinfo/attempto
>>


-- 
=====================
Joshua Taylor
tayloj at cs.rpi.edu, jtaylor at alum.rpi.edu

"A lot of good things went down one time,
  back in the goodle days."
    John Hartford