haskell

Tsoding live-codes a JSON parser from scratch in Haskell in about 111 lines, using only the standard library. It is an edited Twitch stream that explains the intuition behind parser combinators, functors, applicatives and monads.

David Beazley's PyCon 2019 tutorial derives the lambda calculus from the ground up in Python, using only single-argument functions. He builds booleans, numerals and more with no other language features.

Jon Gjengset's long live-coding stream explains Rust's Pin and Unpin types: why they exist, how they work, and how they connect to futures and async/await. It also covers moving from pre-pinning code to the new model.

In this first Crust of Rust episode, Jon Gjengset live-codes an example that needs multiple explicit lifetime annotations. Along the way he covers string types and generics over a custom trait.

David Sanders gives the first part of a two-part introduction to the Julia programming language at SciPy 2014. It walks through the language's basics and its appeal for scientific computing.