The Power of Composition

on YouTube ↗01h 02m

" summary

Argues composition builds large systems from tiny reusable functions and types, demonstrated with a Roman‑numerals pipeline, a composable FizzBuzz using a two‑track result type, and a complete object‑free web app (F# examples, C# shown where helpers are needed). Shows currying and partial application turn multi‑arg functions into chainable one‑arg functions, uses bind/flatMap for branching results (monads), and Kleisli-style composition for HTTP handlers (async option httpContext, used in Giraffe). All examples are implemented and shown working.

AI-written summary · about

" chapters (11)

1. 0:00Start
2. 0:47The Power Of Composition
3. 1:58Prerequisites for understanding composition
4. 2:51Lego Philosophy
5. 6:48Four ideas behind FP
6. 31:04The Replace function
7. 40:06A simple F# implementation
8. 40:53Pipeline implementation
9. 50:53FP terminology
10. 56:47A complete web app
11. 58:34Review

" related talks

• 01h 01mThe power of compositionScott Wlaschin · DotNext 2019 Moscow
• 01h 02mThe Power of CompositionScott Wlaschin · NDC Oslo 2018
• 01h 01mFunction Composition in Programming LanguagesConor Hoekstra · CppNorth 2023
• 59mPipeline-oriented programmingScott Wlaschin · DotNext 2021 Moscow
• 42mThe Power of Function CompositionConor Hoekstra · Lambda World 2024
• 57mBuilding an Intuition for CompositionSy Brand · CppCon 2020
• 48mThe Power of Function CompositionConor Hoekstra · Craft Conference 2024
• 01h 06mThe Functional Programmer's ToolkitScott Wlaschin · NDC London 2019