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A Haskell library that simplifies access to remote data, such as databases or web-based services.

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Statistics on Haxl

Number of watchers on Github 3069
Number of open issues 6
Average time to close an issue 28 days
Main language Haskell
Average time to merge a PR 1 day
Open pull requests 6+
Closed pull requests 35+
Last commit over 2 years ago
Repo Created about 6 years ago
Repo Last Updated about 2 years ago
Size 396 KB
Organization / Authorfacebook
Latest Release0.5.1.0
Page Updated
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Haxl is a Haskell library that simplifies access to remote data, such as databases or web-based services. Haxl can automatically

  • batch multiple requests to the same data source,
  • request data from multiple data sources concurrently,
  • cache previous requests.

Having all this handled for you behind the scenes means that your data-fetching code can be much cleaner and clearer than it would otherwise be if it had to worry about optimizing data-fetching. We'll give some examples of how this works in the pages linked below.

There are two Haskell packages here:

  • haxl: The core Haxl framework
  • haxl-facebook (in example/facebook): An (incomplete) example data source for accessing the Facebook Graph API

To use Haxl in your own application, you will likely need to build one or more data sources: the thin layer between Haxl and the data that you want to fetch, be it a database, a web API, a cloud service, or whatever.

There is a generic datasource in Haxl.DataSource.ConcurrentIO that can be used for performing arbitrary IO operations concurrently, given a bit of boilerplate to define the IO operations you want to perform.

The haxl-facebook package shows how we might build a Haxl data source based on the existing fb package for talking to the Facebook Graph API.

Where to go next?

Build Status

Haxl open issues Ask a question     (View All Issues)
  • almost 5 years bounded caches
Haxl open pull requests (View All Pulls)
  • Aeson 0.11
  • Specialised requests
  • Equivalence classes on requests.
  • Bounded cache
  • Made ghc 8 not yell at me
  • Update dependencies.
Haxl questions on Stackoverflow (View All Questions)
  • Concurrent data access as in Haxl and Stitch
Haxl list of languages used
Other projects in Haskell