AW: [librecat-dev] A common MARC record path language
Hi Thomas and Patrick! Thank you both for bringing the discussion forward. I must admit that I'm having some problems following here. I read your mails multiple times, really trying to understand your demands. After reading this [1], I hope I'm getting closer. I just want to sum up what I think I've understood so far. Please correct me if I'm wrong.. -- When it comes to cataloging based delimiters (punctuation), there is some inner semantic to the content of the subfields. E.g. =$b in field 245 means something different than :$b. -- There may be data you want to get at whole, which spread over multiple subfields. This information is cannot be described by the range of subfields, but with the closure through punctuation. E.g. in the field 245 00$aHeritage Books archives.$pUnderwood biographical dictionary.$nVolumes 1 2 revised$h[electronic resource] /$cLaverne Galeener-Moore. the data you want to get is Heritage Books archives. Underwood biographical dictionary. Volumes 1 2 revised [electronic resource] Is this what you mean when want to say something like Get me all from field XXX until you hit Y? I guess so. -- Therefore the order of subfields is crucial. While MARCspec allows subfields stated in any order, a result should preserve the subfield order emerging in the field. -- Some fields are linked through specific subfields. There may be some data you want to get dependent on linkage from other fields. I'm not sure if I have an example for this. Maybe you could provide one. Finally I've found a nice example on the MARC21 website [2] (section $i - Relationship information). That my question is, if you want to achieve something like this: Source: 100 1# $aVerdi, Giuseppe, $d1813-1901. 245 10 $aOtello :$bin full score /$cGiuseppe Verdi. 700 1# $iLibretto based on (work) $aShakespeare, William, $d1564-1616. $tOthello. 787 08 $ireproduction of (manifestation) $aVerdi, Giuseppe, 1813-1901. $tOtello.$d Milano: Ricordi, c1913 Result (user display): Verdi, Giuseppe, 1813-1901. Otello : in full score / Giuseppe Verdi Reproduction of Verdi, Giuseppe, 1813-1901. Otello. Milano : Ricordi, c1913 Libretto based on Shakespeare, William, 1564-1616. Othello. Is this something you want to express within a MARCspec? Anyhow a collection of use cases is a great idea. That would help to discover the tasks a MARCspec should cope. But I really need your help here. Maybe a wider audience would also be helpful? Cheers! Carsten [1] http://marc-must-die.info/index.php?title=MARC_issues [2] http://www.loc.gov/marc/bibliographic/bd76x78x.html ___ Carsten Klee Abt. Überregionale Bibliographische Dienste IIE Staatsbibliothek zu Berlin - Preußischer Kulturbesitz Fon: +49 30 266-43 44 02 -Ursprüngliche Nachricht- Von: Thomas Berger [mailto:t...@gymel.com] Gesendet: Mittwoch, 19. Februar 2014 23:06 An: Klee, Carsten; 'Patrick Hochstenbach' Cc: v...@gbv.de; librecat-...@mail.librecat.org; perl4lib@perl.org Betreff: Re: [librecat-dev] A common MARC record path language -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hi Carsten, I think the whole problem lies in the limited expressivity of strings. MARCspec is pretty much close to XPath at its approach, but without regular expressions and functions like first(), last() etc. But even with XPath it would 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 mentioned in the spec, MARCspec is not independent from the application using MARCspec. Taking regular expressions into MARCspec wouldn't make the application more usable, but would blow up the specification. Agreed, therefore regular expressions or other /general/ mechanisms should not the way to go (for specifying MARCspecs - specific implementations may realize it using a regexp implementation at hand) Thus, yes, limited expressivness of strings demands to make the most typical and most important operations on MARC records to be expressible. But if it's too limited (say it could only extract fields or has blind spots - parts of record data which cannot be accessed at all) it wouldn't be of any use. Thus MARCspec's need a convincing approach to the peculiarities of MARC records: Subfields are not always data elements in a proper sense, sometimes they are just marks interspersed into the field content. And as Patrick pointed out there is the presence of non-MARC delimiters (markup) which is crucial for processing of some (sub)fields. Many fields contain ensembles of subfields with one nature, accompanied by other, more data-like subfields of a different nature: - - Most subfields in 700 are a simple copy of some (hypothetical) authority record's 100, however $e and/or $4 denote the function of that
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. MARCspec
is pretty much close to XPath at its approach, but without regular expressions
and functions like first(), last() etc. But even with XPath it would 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
mentioned in the spec, MARCspec is not independent from the application using
MARCspec. Taking regular expressions into MARCspec wouldn't make the
application more usable, but would blow up the specification.
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 = 245.match(/(.*)\s\/\$/)
titleData = 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 = 245
titleData = 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,record)
{
// get the data before the / or = or else
regex = new RegExp((.*)\\s\\ + hitWhat + \\$)
data = getMARCspec(record, marcspec).match(regex)[1]
// now split on subfield
dataSplit = data.split(/\$[a-z0-9]/)
// loop everything into result
for (i = 1; i dataSplit.length-1; i++)
{
result += dataSplit[i] +
}
result += dataSplit[dataSplit.length]
return result
}
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 [sound
recording].
If there is any other approach you can think of, plase 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. Überregionale Bibliographische Dienste IIE
Staatsbibliothek zu Berlin - Preußischer Kulturbesitz
Fon: +49 30 266-43 44 02
-Ursprüngliche Nachricht-
Von: Thomas Berger [mailto:t...@gymel.com]
Gesendet: Mittwoch, 19. Februar 2014 01:04
An: Klee, Carsten; 'Patrick Hochstenbach'
Cc: v...@gbv.de; librecat-...@mail.librecat.org; perl4lib@perl.org
Betreff: Re: [librecat-dev] A common MARC record path language
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
Am 18.02.2014 17:47, schrieb Klee, Carsten:
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.
Your MARC however will be very much interested in / (or =) 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...
Thomas Berger
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AW: AW: [librecat-dev] A common MARC record path language
Hi Patrick,
I'm sorry for my much more late reply. Since your mail MARCspec [1] developed
a lot. But unfortunately I didn't got a solution for the issue you described.
Honestly, I'm not sure, if I understand the problem which you want to solve
here.
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.
You mentioned the typical case “Take everything from the 245 until you hit the
first / before a subfield”. I thought about this, but didn't came even close
how this could be expressed in MARCspec. How is this solved in Catmandu now?
If you have any suggestions, how this could be expressed in a string, please
give me a hint.
The only thing I can imagine, is a reference to a character within a subfield.
Something like
245$a[0]/-1
could be read as A reference to the last character of the first subfield 'a'
of field 245. Then you could check if the reference character is /. But I
think, that didn't solve your problem, right?
However I would be very glad, if MARCspec gets adopted by Catmandu. If you're
interested, I've written some algorithm rules for MARCspec parsers [2]. They
are very comprehensive. Maybe there is a smarter algorithm, but this might give
you some clue.
Cheers!
Carsten
[1] http://cklee.github.io/marc-spec/marc-spec.html
[2] https://github.com/cKlee/marc-spec/blob/master/marc-spec-parser-rules.md
___
Carsten Klee
Abt. Überregionale Bibliographische Dienste IIE
Staatsbibliothek zu Berlin – Preußischer Kulturbesitz
Fon: +49 30 266-43 44 02
-Ursprüngliche Nachricht-
Von: Patrick Hochstenbach [mailto:patrick.hochstenb...@ugent.be]
Gesendet: Dienstag, 21. Januar 2014 09:57
An: Klee, Carsten; v...@gbv.de; librecat-...@mail.librecat.org;
perl4lib@perl.org
Betreff: Re: AW: [librecat-dev] A common MARC record path language
Hi Carsten
Excuses for the late reply, it took some while to get the system booted
after winter vacations.
You are right in the discussion about which parts should be specified by a
MARCspec language and which part should be implemented as operations on
nodes found. I gave the examples not as a hit for the implementation
language (e.g. if it requires regular expressions or not) but as a
examples of MARC in the wild (non standard tags) and MARC combined with
cataloging rules (where subfields and characters in front of a subfield
have a special meaning).
In daily work I often encounter mapping rules which involve these special
subfield cases (“Take everything from the 245 until you hit the first /
before a subfield”). These things can’t be easily (can it) expressed in
Xpath when using XSTL or MARCspec when using tools like Catmandu..but are
very common and can be shared across tools. I think this would be
candidates to formalise .
Cheers
Patrick
On 06/01/14 16:33, Klee, Carsten carsten.k...@sbb.spk-berlin.de wrote:
On the other hand I could imagine something like 100[0] for the first
100 field (author) and 100[1] for the second and so on. But what is
about repeatable subfields? Maybe someone requires the first subfield a
of the second 100 field. Besides the characters [ and ] are also
valid subfield codes (see [2]).
With substrings it is more complicated. I only could imagine using
regular expressions. Maybe something like 245a[Œ\s(.*)]_10. But for
usability reasons this might be better left to the applications. Isn't
there something in Catmandu like
marc_map('245','my.title', -substring-after = 'Π'); ??
Maybe you have another solution for that?
Another issue I suspect with your last example under
https://metacpan.org/pod/Catmandu::Fix::marc_map
# Copy all 100 subfields except the digits to the 'author' field
marc_map('100^0123456789','author');
In the current MARCspec this would be interpreted as a reference to
subfields ^, 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 of field 100. This is
because ^ is a valid subfield code (see [2]).
So far... I would be happy to read more comments on this.
Cheers!
Carsten
[1] https://github.com/cKlee/marc-spec/issues
[2] http://www.loc.gov/marc/specifications/specrecstruc.html#varifields
___
Carsten Klee
Abt. Überregionale Bibliographische Dienste IIE
Staatsbibliothek zu Berlin – Preußischer Kulturbesitz
Fon: +49 30 266-43 44 02
-Ursprüngliche Nachricht-
Von: Patrick Hochstenbach [mailto:patrick.hochstenb...@ugent.be]
Gesendet: Freitag, 20. Dezember 2013 14:06
An: v...@gbv.de; librecat-...@mail.librecat.org; perl4lib@perl.org
Cc: Klee, Carsten
Betreff: Re: [librecat-dev] A common MARC record path language
Hi
Thanks for this initiative to formalise the path language for MARC
records. In Catmandu our path language is better described at:
https://metacpan.org/pod/Catmandu::Fix::marc_map. It would be an easy
fix
Re: AW: [librecat-dev] A common MARC record path language
Hi Carsten
Excuses for the late reply, it took some while to get the system booted
after winter vacations.
You are right in the discussion about which parts should be specified by a
MARCspec language and which part should be implemented as operations on
nodes found. I gave the examples not as a hit for the implementation
language (e.g. if it requires regular expressions or not) but as a
examples of MARC in the wild (non standard tags) and MARC combined with
cataloging rules (where subfields and characters in front of a subfield
have a special meaning).
In daily work I often encounter mapping rules which involve these special
subfield cases (“Take everything from the 245 until you hit the first /
before a subfield”). These things can’t be easily (can it) expressed in
Xpath when using XSTL or MARCspec when using tools like Catmandu..but are
very common and can be shared across tools. I think this would be
candidates to formalise .
Cheers
Patrick
On 06/01/14 16:33, Klee, Carsten carsten.k...@sbb.spk-berlin.de wrote:
On the other hand I could imagine something like 100[0] for the first
100 field (author) and 100[1] for the second and so on. But what is
about repeatable subfields? Maybe someone requires the first subfield a
of the second 100 field. Besides the characters [ and ] are also
valid subfield codes (see [2]).
With substrings it is more complicated. I only could imagine using
regular expressions. Maybe something like 245a[Œ\s(.*)]_10. But for
usability reasons this might be better left to the applications. Isn't
there something in Catmandu like
marc_map('245','my.title', -substring-after = 'Π'); ??
Maybe you have another solution for that?
Another issue I suspect with your last example under
https://metacpan.org/pod/Catmandu::Fix::marc_map
# Copy all 100 subfields except the digits to the 'author' field
marc_map('100^0123456789','author');
In the current MARCspec this would be interpreted as a reference to
subfields ^, 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 of field 100. This is
because ^ is a valid subfield code (see [2]).
So far... I would be happy to read more comments on this.
Cheers!
Carsten
[1] https://github.com/cKlee/marc-spec/issues
[2] http://www.loc.gov/marc/specifications/specrecstruc.html#varifields
___
Carsten Klee
Abt. Überregionale Bibliographische Dienste IIE
Staatsbibliothek zu Berlin – Preußischer Kulturbesitz
Fon: +49 30 266-43 44 02
-Ursprüngliche Nachricht-
Von: Patrick Hochstenbach [mailto:patrick.hochstenb...@ugent.be]
Gesendet: Freitag, 20. Dezember 2013 14:06
An: v...@gbv.de; librecat-...@mail.librecat.org; perl4lib@perl.org
Cc: Klee, Carsten
Betreff: Re: [librecat-dev] A common MARC record path language
Hi
Thanks for this initiative to formalise the path language for MARC
records. In Catmandu our path language is better described at:
https://metacpan.org/pod/Catmandu::Fix::marc_map. It would be an easy
fix
for us to follow Carsten¹s MARC spec rules and I will gladly implement
it
for our community.
We see these type of MARC paths in programming libraries such as the
projects mentioned below but also in products like XSTL, SolrMarc,
ILS-vendors who need them to define how to index marc, standardisation
bodies like e.g. that provide mapping rules (e.g.
http://www.loc.gov/standards/mods/mods-mapping.html). I tried to make a
small roundup in the past of these projects but it would be great to
have
more extensive look at all current pratices.
In our Catmandu project we found that Xpaths are too verbose for our
librarians to interpret and in practise tied to XSLT-programming which
requires quite some programming skills to read and interpret.
Our paths are very much simplified but still seem to lack some things
that
are available in the MARC data model which would be great to have
available in the MARCspec syntax:
- Notion of pointing to the first item (first author)
- Supporting local defined MARC (sub)fields (e.g. Ex Libris exports
contain all kind of Z30, CAT , etc fields)
- Support for pointing to a subfields that follow a specific character
(e.g. In titles I would like to point to everything after the Œ/Œ in a
245
field).
Cheers and have a nice holiday
Patrick
On 19/12/13 13:16, Jakob Voß v...@gbv.de wrote:
Hi,
Carsten Klee specified a simple path language for MARC records, called
MARC spec. In short it is a formal syntax to refer to selected parts
of a MARC record (similar to XPath for XML):
http://collidoscope.de/lld/marcspec-as-string.html
http://cklee.github.io/marc-spec/marc-spec.html#examples
Similar languages have been invented before but not with a strict
specification, as far as I know. For instance the perl Catmandu::MARC
supports references to MARC fields:
https://metacpan.org/pod/Catmandu::Fix::Inline::marc_map
https://metacpan.org/source/NICS/Catmandu-MARC-
0.103/lib/Catmandu/Fix/Inli
ne/marc_map.pm#L26
Could you
AW: [librecat-dev] A common MARC record path language
Hi Patrick! Hi everyone!
Thanks for looking into MARCspec. I opened some GitHub issues [1] concerning
your enhancement requests. Let me just give you some thoughts on these:
- Supporting local defined MARC (sub)fields (e.g. Ex Libris exports
contain all kind of Z30, CAT , etc fields)
I think this should be supported. The only problem in the current spec is that
the character X is used as a wildcard in the field tag. If someone defined a
local field tag like XYZ this gets interpreted as all fields ending with
YZ. Possible solution is to define another wildcard character like *.
- Notion of pointing to the first item (first author)
and
- Support for pointing to a subfields that follow a specific character
(e.g. In titles I would like to point to everything after the Œ/Œ in a 245
field).
I understand that both are desired very often. But I think that this is maybe a
little bit out of scope. Since XSLT provides this feature and many more like
the last element, the X element, substring-after, substring-before
etc., MARCspec should concentrate on the core MARC data model (fields,
subfields, character positions) and let the rest to the post data processing of
the applications.
If MARCspec would provide these functionalities it quickly will become very
complicated. And maybe it will come into conflicts with already defined data
processing functions in the various applications.
On the other hand I could imagine something like 100[0] for the first 100
field (author) and 100[1] for the second and so on. But what is about
repeatable subfields? Maybe someone requires the first subfield a of the
second 100 field. Besides the characters [ and ] are also valid subfield
codes (see [2]).
With substrings it is more complicated. I only could imagine using regular
expressions. Maybe something like 245a[Œ\s(.*)]_10. But for usability reasons
this might be better left to the applications. Isn't there something in
Catmandu like
marc_map('245','my.title', -substring-after = 'Π'); ??
Maybe you have another solution for that?
Another issue I suspect with your last example under
https://metacpan.org/pod/Catmandu::Fix::marc_map
# Copy all 100 subfields except the digits to the 'author' field
marc_map('100^0123456789','author');
In the current MARCspec this would be interpreted as a reference to subfields
^, 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 of field 100. This is because ^ is a
valid subfield code (see [2]).
So far... I would be happy to read more comments on this.
Cheers!
Carsten
[1] https://github.com/cKlee/marc-spec/issues
[2] http://www.loc.gov/marc/specifications/specrecstruc.html#varifields
___
Carsten Klee
Abt. Überregionale Bibliographische Dienste IIE
Staatsbibliothek zu Berlin – Preußischer Kulturbesitz
Fon: +49 30 266-43 44 02
-Ursprüngliche Nachricht-
Von: Patrick Hochstenbach [mailto:patrick.hochstenb...@ugent.be]
Gesendet: Freitag, 20. Dezember 2013 14:06
An: v...@gbv.de; librecat-...@mail.librecat.org; perl4lib@perl.org
Cc: Klee, Carsten
Betreff: Re: [librecat-dev] A common MARC record path language
Hi
Thanks for this initiative to formalise the path language for MARC
records. In Catmandu our path language is better described at:
https://metacpan.org/pod/Catmandu::Fix::marc_map. It would be an easy fix
for us to follow Carsten¹s MARC spec rules and I will gladly implement it
for our community.
We see these type of MARC paths in programming libraries such as the
projects mentioned below but also in products like XSTL, SolrMarc,
ILS-vendors who need them to define how to index marc, standardisation
bodies like e.g. that provide mapping rules (e.g.
http://www.loc.gov/standards/mods/mods-mapping.html). I tried to make a
small roundup in the past of these projects but it would be great to have
more extensive look at all current pratices.
In our Catmandu project we found that Xpaths are too verbose for our
librarians to interpret and in practise tied to XSLT-programming which
requires quite some programming skills to read and interpret.
Our paths are very much simplified but still seem to lack some things that
are available in the MARC data model which would be great to have
available in the MARCspec syntax:
- Notion of pointing to the first item (first author)
- Supporting local defined MARC (sub)fields (e.g. Ex Libris exports
contain all kind of Z30, CAT , etc fields)
- Support for pointing to a subfields that follow a specific character
(e.g. In titles I would like to point to everything after the Œ/Œ in a 245
field).
Cheers and have a nice holiday
Patrick
On 19/12/13 13:16, Jakob Voß v...@gbv.de wrote:
Hi,
Carsten Klee specified a simple path language for MARC records, called
MARC spec. In short it is a formal syntax to refer to selected parts
of a MARC record (similar to XPath for XML):
http://collidoscope.de/lld/marcspec-as-string.html
