Beginner's Hands-On with Haskell

An interactive workshop for newcomers to Haskell and functional programming. Led at the Louisville Haskell Meetup

Transcript

1. Haskell Basics A Workshop-ish Thing
2. Tools
3. stack • Bundles useful tools • Simplifies getting started
4. ghci • GHC’s REPL • Commands are vim-like • See what’s available with `:help`
5. FP Principles
6. First-Class Functions • Functions are values • JS: var add1 = function (a) { return a + 1; }; • HS: let add1 = \a -> a + 1
7. Higher-Order Functions • Functions can be passed to other functions • JS: [1,2,3].map(add1); • HS: map add1 [1,2,3]
8. Composition • Small functions can be composed into big functions • let adder = \a b -> a + b • let add1 = \a -> adder a 1 • Partial application • let add2 = adder 2
9. (Im)Purity • Referential Transparency: – f(‘a’) will always be ‘b’ • Effects: – we can't control the world, so let's describe how it will change
10. Laziness • All data isn’t needed all of the time • head [1..]