Here’s a simple program I wrote on a whim tonight, to take a very basic look at GHC’s low-level threading performance. module Main where import Control.Applicative import Control.Concurrent.MVar import Control.Concurrent import Data.Time import System.Environment main = do mv <- newEmptyMVar…

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…

Tired of imperative programmers kicking sand in your face? Send some cut-out lambdas and a postal order for 5 frobs to haskell.org, and we’ll send you a handy-dandy poster of those famous superheroes, the Monad Squad! State helps functional programmers…

POPL 08 takes place next week, so San Francisco will be flooded with an army of burly and menacing programming language researchers and type theorists. Kids, don’t say you haven’t been warned. On Wednesday evening, January 9, Phil Wadler will…

Every language’s standard library has its weak spots. In C, for example, the stdio functions don’t have a consistent notion of where the FILE * belongs in the argument list. For fwrite, it goes at the end; for fseek, it’s…

When debugging or profiling Haskell code, it’s common practice to pepper it with cost centre annotations, often called SCC (for strongly connected component set cost centre) annotations. If you compile a program using ghc -prof -auto-all, this causes all of…