SPARQL Via HTTP Methods

Querying the web might get a bit easier, with the union of SPARQL directly with HTTP. TripleSoup, a promising proposal at Apache, aims to expose Triple Stores (RDF databases) directly via HTTP.

This reminds me of URIQA, which is an effort to provide native HTTP methods for accessing metadata about a certain resource. URIQA was interesting because it allows you to say

MGET /foo HTTP/1.1

which means "Retrieve the metadata for resource `/foo`"

It looks like TripleSoup is a bit different, in that the URI in the request methods is some type of application. TripleSoup seems to be a gateway directly into the triple store, whereas URIQA masks the concept of talking to the triple store. In URIQA, it looks like the triple store *is* the server you are connecting to. With TripleSoup, the triple store is located at the URI you are sending requests to.

URIQA's advantage is that you don't need to know the URI to the application or triple store, you can just send an MGET to the resource. Of course, URIQA doesn't handle queries with SPARQL.

My first question with TripleSoup is, how would I discover the URI that I can use for querying? It's the same problem that URIQA tries to solve, "I know the URI for the resource, but I want to get its metadata." I can ask that question in SPARQL, but who do I ask?

Best of luck to the TripleSoup team, really looking forward to the code.

Popular posts from this blog

Lists and arrays in Dart

(This is Part 3 in a series about Dart. Check out Part 2, Function in Dart .) Warning : We expect the Dart libraries to undergo potentially sweeping changes before Dart goes to alpha. This document is relevant as of 2011-12-22. Intro Dart is a "batteries included" effort to help app developers build modern web apps. An important "battery" is the bundled core Dart libraries, providing common and rich functionality. Dart is building a solution for large, complex web apps, and providing well tested, integrated, and common libraries is key to helping a web app developer be more productive out of the box. The Collection libraries are a crucial set of APIs that Dart developers get for free. Much more than simple arrays and maps, the Collection library includes standard ways to filter, iterate, inspect, compose, and sort your data. This post specifically looks at List<E> , Dart's ordered, indexable collection of objects. Aside: The Dart project is lucky
Read more

Converting Array to List in Scala

Now, this has to have a built-in somewhere in Scala , because it just seems too common. So, how to convert an Array to a List in Scala? Why do I need this? I needed to drop to Java for some functionality, which in this case returns an Array. I wanted to get that Array into a List to practice my functional programming skillz. **Update**: I figured out how to convert Arrays to Lists the Scala way. Turns out it's a piece of cake. val myList = List.fromArray(Array("one", "two", "three")) or val myList = Array("one","two","three").elements.toList The call to elements returns an Iterator , and from there you can convert to a List via toList . Nice. Because my first version wasn't actually tail recursive, what follows is a true tail recursive solution, if I were to implement this by hand. The above, built in mechanism is much better, though. object ArrayUtil { def toList[a](array: Array[a]): List[a] = { d
Read more

Null-aware operators in Dart

Image
Three new language features just landed in the latest dev channel build of the Dart ! Collectively known as null-aware operators , these new features will help you reduce the code required to work with potentially null objects. I'm excited for these new abilities, because typing less is always a good thing. Read on to learn more, and be sure to try these new features on Dart Pad . ?? Use ?? when you want to evaluate and return an expression IFF another expression resolves to null. exp ?? otherExp is similar to ((x) => x == null ? otherExp : x)(exp) ??= Use ??= when you want to assign a value to an object IFF that object is null. Otherwise, return the object. obj ??= value is similar to ((x) => x == null ? obj = value : x)(obj) ?. Use ?. when you want to call a method/getter on an object IFF that object is not null (otherwise, return null). obj?.method() is similar to ((x) => x == null ? null : x.method())(obj) Yo
Read more