High-level introduction to Functional Programming and Haskell

This is suitable for software developers but also for other team members with a general technical understanding of programming.

The goals of this course are to

•  Understand what functional programming is about, what differences between functional languages exist, and how Haskell fits into this space
•  Contrast the approaches of different programming languages to programming problems by example
•  Look at several examples of how to solve programming problems in Haskell
•  Discuss how the type system of Haskell helps in precisely modelling domains, thereby not just preventing all kinds of errors at an early stage, but also helping with development
•  Allow participants to develop a superficial understanding of Haskell syntax and how to read it
•  Write a few very small Haskell programs

The position of Haskell among programming languages

•  Imperative, object-oriented and functional programming languages
•  Dynamic vs static types
•  High-level vs low-level (systems) languages
•  Higher-order functions
•  Lazy vs eager evaluation
•  Implicit vs explicit (side) effects

Algebraic datatypes for domain modelling

•  Nominal vs structural type systems
•  Light-weight type safety by introducing meaningful domain-specific concepts
•  Controlling the interface of user-defined datatypes
•  Optional values, union types
•  Sum types, enumeration types
•  Parameterized datatypes and polymorphism
•  How types can provide guidance during programming

Advantages of parametric polymorphism

•  How making a function more generic restricts its implementation in a good way
•  How to make true statements about functions just by looking at their types
•  Contrasting with other forms of polymorphism

Compositionality and higher order functions

•  The power of abstraction (and when to use it)
•  How to decompose functional programming problems into smaller parts
•  Lazy vs eager evaluation
•  How the evaluation strategy affects program structure

Explicit effects

•  How Haskell makes side effects explicit
•  The IO type
•  Advantages of explicit effects
•  Using explicit effects
•  Embedded domain-specific languages with multiple interpreters