Typed Design Patterns for the Functional Era
summary
Argues that some recurring system designs resist being encoded purely as libraries and shows four Rust encodings: Witness, State Machine, Parallel Lists, Registry. Implements the Registry pattern as a working event system using Rust TypeId plus downcasting so the hashmap key is the payload type, not a string, and compilation prevents triggering a click handler with a keypress. Demonstration compiles and runs; trade-offs include subtle mismatches when types use references or wrappers — those remain developer pitfalls. type-driven keys
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chapters (6)
- 0:00The quest for FP patterns
- 2:30Defining design patterns
- 5:04Patterns and language design
- 7:24Rust as a functional case
- 11:36The registry pattern
- 25:50Discussion and conclusion
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