Haskell Weekly

Welcome to another issue of Haskell Weekly! Haskell is a safe, purely functional programming language with a fast, concurrent runtime. This is a weekly summary of what’s going on in its community.

Featured

• Я ☞ Context-free effects with Monoidal functors by Murat Kasimov

  Monoidal functor is a special kind of functor between categories with some tensor. You can think on tensor as a placeholder for either a product or a sum of objects.

• Chat Bots Revisited by Solomon Bothwell

  It has been a long while since my last post on chat bots; quite a bit longer then I intended to be honest. I would like to summarize here where the project has gotten as I think it has some cool ideas worth documenting.

• Generic-case: automatic case analysis with no boilerplate by Frederick Pringle

  Data.Maybe.maybe, Data.Bool.bool and Data.Either.either all follow a pattern, which is sometimes called “case analysis”: for each constructor of a given type T, provide me a function from the product of the constructor types to a result type r; and I’ll give you back a function from T to r. generic-case unifies this pattern and generalises it for any type with an instance of Generic from generics-sop.

• “Learn Haskell by Example” book presentation by Philipp Hagenlocher

  In Learn Haskell by Example, you’ll build your Haskell skills by working through hands-on challenges and conundrums. You’ll learn to look at each project through a Haskell lens, and then solve it using features like lazy evaluation, immutable data structures, and monads.

In brief

• containers 0.8

  See the changelog for what’s changed.

Show & tell

• How to use GHC 7.10 by Janus Troelsen

  I managed to get a working GHC 7.10 setup, and I wanted to put all the necessary information in one place, just for future reference.

Call for participation

• hs-bindgen: Generate type-level bindings for certain macros
• nix-output-monitor: Nom build shows “Exited with traces” rather than finished