Functional Programming Fundamentals

This skill covers the foundational concepts of functional programming. Master these before diving into fp-ts types like Option, Either, and Task. These concepts apply universally across functional programming languages and libraries.

Why Functional Programming?

Functional programming provides:

• Predictability: Pure functions always produce the same output for the same input
• Testability: No mocking of global state or dependencies
• Composability: Small functions combine into complex behavior
• Maintainability: Isolated pieces are easier to understand and change
• Parallelization: Pure functions can safely run concurrently

1. Pure Functions and Referential Transparency

What is a Pure Function?