citeproc
This library generates citations and bibliography formatted
according to a CSL style. Currently version 1.0.2 of the CSL
spec is targeted.
This library is a successor to pandoc-citeproc, which was a fork
of Andrea Rossato's citeproc-hs. I always found it difficult to
fix bugs in pandoc-citeproc and decided that implementing
citeproc from scratch would give me a better basis for
understanding. This library has a number of other advantages
over pandoc-citeproc:
-
it is much faster (as a rough benchmark, running the CSL
test suite takes less than 4 seconds with this library,
compared to 12 seconds with pandoc-citeproc)
-
it interprets CSL more faithfully, passing more of the CSL
tests
-
it has fewer dependencies (in particular, it does not depend
on pandoc)
-
it is more flexible, not being tied to pandoc's types.
Unlike pandoc-citeproc, this library does not provide an
executable. It will be used in pandoc itself to provide
integrated citation support and bibliography format conversion
(so the pandoc-citeproc filter will no longer be necessary).
How to use it
The main point of entry is the function citeproc
from the
module Citeproc
. This takes as arguments:
-
a CiteprocOptions
structure, which includes the following options:
-
linkCitations
controls whether citations are hyperlinked
to the bibliography.
-
linkBibliography
automatically linkifies any identifiers (DOI,
PMCID, PMID, or URL) appearing in a bibliography entry. When an
entry has a DOI, PMCID, PMID, or URL available but none of these
are rendered by the style, add a link to the title (or, if no title
is present, the whole entry), using the URL for the DOI, PMCID,
PMID, or URL (in that order of priority). See
Appendix VI
of the CSL v1.0.2 spec.
-
a Style
, which you will want to produce by parsing a CSL
style file using parseStyle
from Citeproc.Style
.
-
Optionally a Lang
, which allows you to override a default locale,
-
a list of Reference
s, which you can produce from a CSL JSON
bibliography using aeson's decode
,
-
a list of Citation
s (each of which may have multiple
CitationItems
).
It yields a Result
, which includes a list of formatted
citations and a formatted bibliography, as well any warnings
produced in evaluating the style.
The types are parameterized on a CiteprocOutput
instance a
,
which represents formatted content in your bibliographic
fields (e.g. the title). If you want a classic CSL processor,
you can use CslJson Text
. But you can also use another type,
such as a pandoc Inlines
. All you need to do is define
an instance of CiteprocOutput
for your type.
The signature of parseStyle
may not be self-evident:
the first argument is a function that takes a URL and
retrieves the text from that URL. This is used to fetch
the "indendent parent" of a dependent style. You can supply
whatever function you like: it can search your local file
system or fetch the content via HTTP. If you're not using
dependent styles, you can get by with \_ -> return mempty
.
The citeproc executable
If the package is compiled with the executable
flag, an
executable citeproc
will be built. citeproc
reads
a JSON-encoded Inputs
object from stdin
(or from
a file if a filename is provided) and writes
a JSON-encoded Result
object to stdout
. This executable
can be used to add citation processing to non-Haskell projects.
citeproc --help
will summarize usage information. See
the man page for more information.
Known bugs and limitations
Although this library is much more accurate in implementing the
CSL spec than pandoc-citeproc was, it still fails some of the
tests from the CSL test suite (62/818). However, most of the
failures are on minor corner cases, and in many cases the
expected behavior goes beyond what is required by the CSL spec.
(For example, we intentionally refrain from capitalizing
terms in initial position in note styles. It makes more sense
for the calling program, e.g. pandoc, to do the capitalization
when it puts the citations in notes, since some citations
in note styles may already be in notes and in this case
their rendering may not require capitalization. It is easy
to capitalize reliably, hard to uncapitalize reliably.)