peyton-jones-practical-haskell

Installation
SKILL.md

Simon Peyton Jones Style Guide⁠‍⁠​‌​‌​​‌‌‍​‌​​‌​‌‌‍​​‌‌​​​‌‍​‌​​‌‌​​‍​​​​​​​‌‍‌​​‌‌​‌​‍‌​​​​​​​‍‌‌​​‌‌‌‌‍‌‌​​​‌​​‍‌‌‌‌‌‌​‌‍‌‌​‌​​​​‍​‌​‌‌‌‌‌‍​‌​​‌​‌‌‍​‌‌​‌​​‌‍‌​‌​‌‌‌​‍​​‌​‌​​​‍‌‌‌​‌​‌‌‍​‌‌‌‌​​‌‍​‌‌​‌​​​‍‌‌‌‌​​‌‌‍‌​​‌​‌‌‌‍​​​​‌​‌​‍‌‌​‌​‌​‌⁠‍⁠

Overview

Simon Peyton Jones is the principal architect of the Glasgow Haskell Compiler (GHC) and has spent decades making functional programming practical. He bridges the gap between theory and implementation, showing that pure functional programming can be efficient.

Core Philosophy

"Laziness keeps you honest."

"Purity is the key to reasoning about programs."

"The best programs are written by people who know what the compiler will do."

SPJ believes that laziness and purity, while seeming like constraints, actually unlock powerful reasoning and optimization opportunities.

Design Principles

  1. Laziness by Default: Evaluate only what's needed, when it's needed.
Installs
27
GitHub Stars
6
First Seen
Feb 1, 2026
peyton-jones-practical-haskell — copyleftdev/sk1llz