Advanced Pattern Matching in C#

on YouTube ↗01h 02m

" summary

Walks through concrete C# pattern features added in C# 7–11 pattern features (type, property, positional/tuple, relational, list and spread patterns), shows span<T> for performance when matching lists, and ports a Haskell red‑black tree balance function into C# using pattern matches. Demonstrates a runnable library with 514 unit tests passing, explains how tuple syntax becomes positional patterns, and proves the port is concise, maintainable and functionally equivalent to the original implementation.

AI-written summary · about

" chapters (13)

1. 0:00Introduction to pattern matching
2. 1:26Use cases and perspective
3. 3:21Porting algorithms
4. 6:09C# feature history
5. 8:20Syntax examples and basics
6. 12:37Advanced pattern matching
7. 16:28Nested paths and Refactoring
8. 19:43List and Span matching
9. 26:00Interesting side cases
10. 35:56Changing industry guidance
11. 39:56Functional programming in C#
12. 48:32Porting complex examples
13. 52:57Live demo and conclusion

" related talks

• 52mFunctional Patterns for the Object OrientedØystein Kolsrud · NDC Oslo 2019
• 01h 03mC# 7Jon Skeet · NDC London 2018
• 01h 03mFunctional Programming with C#Simon Painter · NDC Oslo 2020
• 56mChange your habits: Modern techniques for modern C#Bill Wagner · NDC London 2020
• 59mLet’s catch up with C#! Exciting new features in C# 9, 10, 11, 12 and 13!Filip Ekberg · NDC Copenhagen 2025
• 58mFunctional Programming with C#Simon Painter · NDC Porto 2022
• 54mImplementing Modern Types in C#Rob Ashton · DevConf 2023
• 55mThe State of C# - What Have I MissedFilip Ekberg · NDC Oslo 2018