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criterion is a library that makes accurate microbenchmarking in Haskell easy. Features The simple API hides a lot of automation and details that you shouldn’t need to worry about. Sophisticated, high-resolution analysis can accurately measure operations that run in as little as a few hundred picoseconds. Output to active HTML (with Javascript charts), CSV, and JSON. Write your own report templates

I’m pleased to introduce the third generation of my attoparsec parsing library. With a major change to its internals, it is both faster and more powerful than previous versions, while remaining backwards compatible. Comparing to C Let’s start with a speed comparison between the hand-written C code that powers Node.js’s HTTP parser and an idiomatic Haskell parser that uses attoparsec. There are goo

I threw together a little code tonight to calculate the Katz centrality of packages on Hackage. This is a measure that states that a package is important if an important package depends on it. The definition is recursive, as is the matrix computation that converges towards a fixpoint to calculate it. Here are the top hundred Hackage packages as calculated by this method, along with their numeric m

wreq is a library that makes HTTP client programming in Haskell easy. Features Simple but powerful lens-based API Over 100 tests, and built on reliable libraries like http-client and lens Session handling includes connection keep-alive and pooling, and cookie persistence Automatic decompression Powerful multipart form and file upload handling Support for JSON requests and responses, including navi

For a while now, I’ve had it in mind to improve the encoding performance of my Haskell JSON package, aeson. Over the weekend, I went from hazy notion to a proof of concept for what I think could be a reasonable approach. This post is a case of me “thinking out loud” about the initial design I came up with. I’m very interested in hearing if you have a cleaner idea. The problem with the encoding met

Over the past few months, the Sigma engineering team at Facebook has rolled out a major Haskell project: a rewrite of Sigma, an important weapon in our armory for fighting spam and malware. Sigma has a mission-critical job, and it needs to scale: its growing workload currently sees it handling tens of millions of requests per minute. The rewrite of Sigma in Haskell, using the Haxl library that Sim

Home › software › haskell › Announcing a major revision of the Haskell text library I'm pleased to announce the availability of version 0.5 of text, a library that provides fast Unicode text handling for Haskell. This version contains numerous changes compared to version 0.4, in three broad categories: I made improvements to the performance of some common functions by, in many cases, more than 10x

On behalf of the Data.Text team, I am delighted to announce the release of preview versions of two new packages: text 0.1 Fast, packed Unicode text support, using a modern stream fusion framework. text-icu 0.1 Augments the text package with comprehensive character set conversion support and normalization (and soon more), via bindings to the ICU library. These packages fill out critical pieces of f

Is there a copy’n’paste error in Prelude> dropPrefix “foolish” “football” (“lish”, “ball”) which should rather be Prelude> dropPrefix “foolish” “football” (“lish”, “tball”) ?

Home › software › haskell › The basics of applicative functors, put to practical work Applicative functors are gorgeous and versatile creatures, but as is common in Haskell, they lack a little in documentation. The paper that Conor and Ross wrote introducing them is good, but dense. What if we were to skip all the scene-setting kerfuffle, and plunge into using them by example? I won’t attempt to d

Someone showed up on #haskell yesterday, asking how to use regular expressions. This isn’t a completely straightforward question to answer. While Haskell’s regexp libraries provide the same functionality you’ll find in Perl, Python, and Java, they provide a rich and fairly abstract interface that can be daunting to newcomers. So let’s fix that, and strip away the abstractions to show how we might

Hey there I am new to the subject of thread. Can someone tell me why is the average time that using pthread_create() to creat a thread is shorter than using fork() to create a process? My thought is that because parent process has to wait for each child process. On the other hand, thr_create.c includes which only needs to wait for the last thread. Am I correct? Hi Benson, Threads are faster than a