citeproc-hs-0.3.2: A Citation Style Language implementation in Haskell

MaintainerAndrea Rossato <>




citeproc-hs is a library for automatically formatting bibliographic reference citations into a variety of styles using a macro language called Citation Style Language (CSL). More details on CSL can be found here:

This module documents and exports the library API.



citeproc-hs provides functions for reading bibliographic databases, for reading and parsing CSL files and for generating citations in an internal format, FormattedOutput, that can be easily rendered into different final formats. At the present time only Pandoc and plain text rendering functions are provided by the library.

The library also provides a wrapper around hs-bibutils, the Haskell bindings to Chris Putnam's bibutils, a library that interconverts between various bibliography formats using a common MODS-format XML intermediate. For more information about hs-bibutils see here:

citeproc-hs can natively read MODS and JSON formatted bibliographic databases. The JSON format is only partially documented. It is used by citeproc-js, by the CSL processor test-suite and is derived by the CSL scheme. More information can be read here:

A (git) repository of styles can be found here:

Overview: A Simple Example

The following example assumes you have installed citeproc-hs with hs-bibutils support (which is the default).

Suppose you have a small bibliographic database, like this one:

 author="Andrea Rossato",
 title="My Second Book",

 author="Roberto Caso",
 title="Roberto's Book",

Save it as mybibdb.bib.

Then you can grab one of the CSL styles that come with the test-suite for CSL processors. Suppose this one:

saved locally as apa-x.csl.

This would be a simple program that formats a list of citations according to that style:

 import Text.CSL

 cites :: [Cite]
 cites = [emptyCite { citeId = "Caso2007"
                    , citeLabel = "page"
                    , citeLocator = "15"}
         ,emptyCite { citeId = "Rossato2006"
                    , citeLabel = "page"
                    , citeLocator = "10"}

 main :: IO ()
 main = do
   m <- readBiblioFile "mybibdb.bib"
   s <- readCSLFile "apa-x.csl"
   let result = citeproc procOpts s m $ [cites]
   putStrLn . unlines . map (renderPlainStrict) . citations $ result

The result would be:

 (Caso, 2007, p. 15; Rossato, 2006, p. 10)

Reading Bibliographic Databases

readBiblioFile :: FilePath -> IO [Reference]Source

Read a file with a bibliographic database. The database format is recognized by the file extension.

Supported formats are: json, mods, bibtex, biblatex, ris, endnote, endnotexml, isi, medline, and copac.

readModsFile :: FilePath -> IO ReferenceSource

Read a file with a single MODS record.

readModsCollectionFile :: FilePath -> IO [Reference]Source

Read a file with a collection of MODS records.

Reference Representation

setNearNote :: Style -> [[Cite]] -> [[Cite]]Source

CSL Parser, Representation, and Processing

readCSLFile :: FilePath -> IO StyleSource

Read and parse a CSL style file into the internal style representation, the Style.

The Style Types

data Style Source

The representation of a parsed CSL style.

data Affix Source


Eq Affix 
Data Affix 
Ord Affix 
Read Affix 
Show Affix 
Typeable Affix 
JSON Affix

Needed for the test-suite.

High Level Processing

data ProcOpts Source




bibOpts :: BibOpts

citeproc :: ProcOpts -> Style -> [Reference] -> Citations -> BiblioDataSource

With a Style, a list of References and the list of Citations, produce the FormattedOutput for each citation group and the bibliography.

processCitations :: ProcOpts -> Style -> [Reference] -> Citations -> [[FormattedOutput]]Source

With a Style, a list of References and the list of citation groups (the list of citations with their locator), produce the FormattedOutput for each citation group.

processBibliography :: ProcOpts -> Style -> [Reference] -> [[FormattedOutput]]Source

With a Style and the list of References produce the FormattedOutput for the bibliography.

data BiblioData Source




The output and the rendering functions

data FormattedOutput Source

The formatted output, produced after post-processing the evaluated citations.

renderPlain :: [FormattedOutput] -> StringSource

Render the FormattedOutput into a plain text string.

renderPlainStrict :: [FormattedOutput] -> StringSource

Same as renderPlain , but will not clean up the produced output.

renderPandoc :: Style -> [FormattedOutput] -> [Inline]Source

With a Style and the formatted output generate a String in the native Pandoc formats (i.e. immediately readable by pandoc).

renderPandoc' :: Style -> [FormattedOutput] -> BlockSource

Same as renderPandoc, but the output is wrapped in a pandoc paragraph block.