Neil Mitchell's Blog (Haskell etc)

Summary: The rough rule I use for teams I'm on is make at least one PR per day. One of the principles I've used quite successfully i...

Summary: A very high-level view of the engineering aspects of Shake. The theory behind Shake is now well documented in the Build Systems a l...

Summary: HLint is going to switch to the GHC parser over the next few months. The plan is below. For some time, HLint has been accumulating ...

Summary: Hoogle 5.0.17.6 and below have an XSS vulnerability, fixed in later versions. On Friday afternoon I got an email from Alexander Gug...

Summary: Shake now does that Applicative trick from Haxl. In Shake 0.17.9 and below, need xs >> need ys builds xs in parallel, then ...

Summary: The foldr function seems simple, but is actually very complex, with lots of layers. This post dives through the layers. The foldr ...

Summary: The only way to understand a code base is to ask someone who works on it. This weekend a relative asked me how can we tell who wrot...

Summary: Code review is not a yes/no decision - mostly I say yes with suggestions. As I wrote previously , I didn't used to be a fan of ...

Summary: GHC rebuild times are slow. Using the Shake profiler and Hadrian we can find out why. I just checked out GHC , and using Hadrian (...

Summary: For large data types, deriving Generic can take a long time to compile. I was building GHC using Hadrian , and part of that proce...

On behalf of Digital Asset I'm delighted to announce ghc-lib , a repackaging of the GHC API to allow it to be used on different GHC ver...

Summary: HLint detects unused extensions in LANGUAGE pragmas, including over 17,000 on Hackage. HLint has detected unused LANGUAGE pragma...

Summary: There are two steps that delay new versions of packages in Stackage. I aim to get the latest version of my software out to as many ...

Summary: HLint now has more ways to ignore hints you don't like. HLint makes suggestions about how to improve your Haskell code. But no...

Summary: The story of another bug, from report, patch, revisions, to merge. I recently posted the story of a GHC bug that took 3 months to ...

Summary: The story of a bug, from report, proposal, patch, revisions, to merge. A while ago I found a bug in GHC . Like all good bugs, this ...

Summary: Haskell uses :: as the type operator. That was a mistake that costs us over 1 million characters of source code. Haskell uses :: f...

Summary: I wanted to download the latest version of every package in Hackage. Here's a script and explanation of how to do it. Imagine y...

Summary: profiterole reformats GHC profile reports so they are easier to read. Do you often work with GHC time profiling reports? Do you fi...

I'm delighted to announce Shake 0.17. As always, the full changelog is on GitHub , but I'd like to highlight three areas that have s...