olexandryermilov/wax

wax :: IO FunctionalWorkshop

Collection of training materials for the functional workshop.

Day 1: Go to the classes to meet your type classes

Plan

1. Type classes.
   1. Introduce the problem.
      1. Abstraction.
      2. Composability.
      3. Extensibility.
   2. Use example with code we don’t own.
   3. Solve the problem with wrappers.
   4. Introduce idea of the type classes.
   5. Implicits (Haskell: show the difference).
2. Semigroup.
   1. Formal definition.
   2. Informal definition with example in host language.
   3. Note importance of laws for type classes.
   4. Instance examples.
   5. Checking the laws.
      1. Manually (pen and paper).
      2. Automatically (property based testing).
   6. Note that it’s very common for the data types to have multiple instances of semigroup.
   7. More examples of semigroups.
   8. H/W: write an instance that breaks the laws.
3. Monoid.
   1. Format definition.
   2. Informal definition with example in host language.
   3. Monoid laws.
   4. Instance examples.
   5. Not all semigroups are monoids. Provide examples.
4. Workshop.
   1. Fibonacci.
   2. Calculate top used words in huge amount of files.
   3. Logging.