AW: [librecat-dev] A common MARC record path language

Hi Thomas and Patrick!

I think the whole problem lies in the limited expressivity of strings. MARC=
spec is pretty much close to XPath at its approach, but without regular exp=
ressions and functions like first(), last() etc. But even with XPath it wou=
ld be pretty hard to get the character before a subfield in a MARCXML file.

The only solution I can think of, is using regular expressions. And I'm not=
 convinced that bringing this into MARCspec is a good idea. As I already me=
ntioned in the spec, MARCspec is not independent from the application using=
 MARCspec. Taking regular expressions into MARCspec wouldn't make the appli=
cation more usable, but would blow up the specification.=20

One example:

The data in field 245 is:

"$aConcerto per piano n. 21, K 467$h[sound recording] /$cW.A. Mozart"

The desired result is (rule: take everything from 245 until the string ' /$=
' appears):

"Concerto per piano n. 21, K 467 [sound recording]"

Imagine a MARCspec with regular expression. // pseudo code coming up!

marcspec =3D "245.match(/(.*)\s\/\$/)"
titleData =3D getMARCspec(record, marcspec)
print titleData[1]
// should result in "$aConcerto per piano n. 21, K 467$h[sound recording]"

Now pretty the same but without the regular expression in the MARCspec.

marcspec =3D "245"
titleData =3D getMARCspec(record, marcspec).match(/(.*)\s\/\$/)
print titleData[1]
// should result in "$aConcerto per piano n. 21, K 467$h[sound recording]"

You see, nothing won here.

But an application could provide a special function like

function takeEverythingFromSpecUntilYouHitBeforeSubfield(marcspec,hitWhat,r=
ecord)
{
    // get the data before the / or =3D or else
    regex =3D new RegExp("(.*)\\s\\" + hitWhat + "\\$")
    data =3D getMARCspec(record, marcspec).match(regex)[1]

    // now split on subfield
    dataSplit =3D data.split(/\$[a-z0-9]/)

    // loop everything into result
    for (i =3D 1; i < dataSplit.length-1; i++)
    {
        result +=3D dataSplit[i] + " "
    }
    result +=3D dataSplit[dataSplit.length]

    return result=20
}

In Catmandu or elsewhere the user calls the function

takeEverythingFromSpecUntilYouHitBeforeSubfield("245","/",record)

--> this should result in the desired "Concerto per piano n. 21, K 467 [sou=
nd recording]".

If there is any other approach you can think of, pleeeease make a proposal =
or give me a substantial discussion here. Otherwise I can't see any options=
 solving this problem in MARCspec.

Cheers!

Carsten
_______________________________________________
Carsten Klee
Abt. =DCberregionale Bibliographische Dienste IIE
Staatsbibliothek zu Berlin - Preu=DFischer Kulturbesitz

Fon:  +49 30 266-43 44 02

> -----Urspr=FCngliche Nachricht-----
> Von: Thomas Berger [mailto:[email protected]]
> Gesendet: Mittwoch, 19. Februar 2014 01:04
> An: Klee, Carsten; 'Patrick Hochstenbach'
> Cc: [email protected]; [email protected]; [email protected]
> Betreff: Re: [librecat-dev] A common MARC record path language
>=20
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>=20
>=20
>=20
> Am 18.02.2014 17:47, schrieb Klee, Carsten:
>=20
> > I understand that there is MARC data combined with cataloging rules. We
> > don't use this approach within our MARC. So I'm not really aware of the
> problematics.
>=20
> "Your" MARC however will be very much interested in "/" (or "=3D") as the
> first
> character of some subfield in 245 if I recall correctly. Not such a big
> difference I would think. But maybe a slight complication of the matter,
> since MARCspec should have to cope with both approaches...
>=20
> Thomas Berger
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