Effective TypeScript

TypeScript Types: The First 500 Years (tsconf 2021 talk)

My talk from tsconf 2021, TypeScript Types: The First 500 Years, is up on YouTube (slides here). Check it out!

The talk tries to answer the question "what is a type?" It seems simple but it's actually quite tricky! The talk explains how sets can be built constructively ("A" | "B" | "C"), but that the more common approach in TypeScript is best thought of as a subtractive process, where you start from the raw, undifferentiated unknown type and then whittle your way down:

Large block of marble with the word unknown on it

It then talks about how TypeScript has given us the ability to "carve" out finer and finer details in our types over time, and how that lets us capture more and more errors in our code.

Overall I'm happy with how the talk turned out. Let me know what you think! All the tsconf 2021 talks are online now. The Anders keynote is always a highlight.

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Effective TypeScript shows you not just how to use TypeScript but how to use it well. Now in its second edition, the book's 83 items help you build mental models of how TypeScript and its ecosystem work, make you aware of pitfalls and traps to avoid, and guide you toward using TypeScript’s many capabilities in the most effective ways possible. Regardless of your level of TypeScript experience, you can learn something from this book.

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