FP101x – Introduction to Functional Programming

This week, I started the Functional Programming course on edX! Almost all of my recreational programming time has been devoted to Go lately, which is decidedly not functional. But I’m excited about the release of Elixir 1.0 and I’ve been meaning to do more with Clojure, so I think I’ve got a lot more functional programming in my future. Perhaps this course will give me a boost!

Haskell

The course is not a Haskell course per se, but that’s what it uses for all the examples. I installed the Glasgow Haskell Compiler with

sudo apt-get install ghc

That was easy. Thanks, Debian!

$ cat hello.hs
module Main
    where
      main=putStrLn "Hello, World!"
$ ghc -o hello hello.hs
[1 of 1] Compiling Main             ( hello.hs, hello.o )
Linking hello ...
$ ./hello 
Hello, World!

Emacs

Next I configured Emacs for Haskell by adding

(depends-on "haskell-mode")

to my Cask file and

(use-package haskell-mode
  :init
  (progn
    (add-hook 'haskell-mode-hook 'haskell-indent-mode)
    (add-hook 'haskell-mode-hook 'interactive-haskell-mode)))

to my Emacs init file. Now I’m ready to try the first set of exercises!

Figure 2: Emacs in haskell-mode and ghci in terminal