I'm excited to announce the first version of hsparql. HSparql makes it easy to query SPARQL-compliant servers using a relatively intuitive DSL and very simple client. SPARQL is a SQL-ish query language for stores of RDF data. So, SPARQL lets you search the structured data in several big databases. I wrote it so that I could search DBpedia [1], a neat site that pulls structured data from Wikipedia's infoboxes, and also ties it to remote data services like MusicBrainz and US Census information. HSparql isn't tied to DBpedia in any way, though, and can search any server. The DSL looks something like this:
simple :: Query [Variable] simple = do resource <- prefix (iriRef "http://dbpedia.org/resource/") dbpprop <- prefix (iriRef "http://dbpedia.org/property/") foaf <- prefix (iriRef "http://xmlns.com/foaf/0.1/")
x <- var name <- var page <- var
triple x (dbpprop .:. "genre") (resource .:. "Web_browser")
triple x (foaf .:. "name") name triple x (foaf .:. "page") page
return [name, page]
It's currently available on Hackage [2], and at the moment the source is only available from the tarball hosted there. I'd greatly appreciate any feedback on this package. Thanks! Jeff Wheeler [1] http://dbpedia.org/ [2] http://hackage.haskell.org/package/hsparql