parsonsmatt

timestamp :: String -> Q a -> Q a
timestamp name action = do
  start <- runIO getCurrentTime
  runIO $ putStrLn $ "Starting " <> name <> ": " <> show start
  a <- action
  end <- runIO getCurrentTime
  runIO $ do
    putStrLn $ "Ending " <> name <> ": " <> show end
    putStrLn $ "Elapased " <> name <> ": " <> show (diffUTCTime end start)
  pure a

ChrisPenner

Optics By Example Cheat Sheets

The following are appendices from Optics By Example, a comprehensive guide to optics from beginner to advanced! If you like the content below, there's plenty more where that came from; pick up the book!

• Operators
• Composition Guide
• Substitution Guide
• Optical Constarints and Types

Operator Cheat Sheet

serras

Some thoughts on building software

Lately I have been busy reading some new books on Domain Driven Design (DDD) and software architecture -- including a short yet eye-opening one in Python and a great one in F#. At the same time, it seems that more people in the Functional Programming world are looking at more formal approaches to modelling -- some examples here. This has brought some thought from the background of my brain about how we should model, organize, and architect software using the lessons we've learnt from functional programming.

Before moving on, let me be clear about this being just a dump of some thoughts, not always well-defined, definite