optional

Stuart Marks explains the intended purpose and proper use of Java 8's Optional class and why it caused so much controversy. He gives guidelines for using its small API correctly.

A restored HD upload of the 1983 BBC series Fun to Imagine, in which Richard Feynman talks informally about everyday science. Topics include jiggling atoms, fire, rubber bands, magnets, electricity, mirrors, seeing, big numbers and ways of thinking.

Rich Hickey's Clojure/Conj 2018 keynote argues that Maybe/Option types and rigid type signatures are a poor way to model data that changes over time. He builds the case around optionality, schema growth and compatibility, and presents the ideas behind Clojure spec as an alternative.

Aditya Siram introduces Shen, a small hosted Lisp with macros, a built-in Prolog and an optional type system. The talk demos a full web app moving between functional, logic and imperative styles, including turning JSON into a type with macros.

Footage shot in New York City in 1911 by a Swedish film company, upscaled to 4K and 60 fps with neural networks and optionally colorized. The creator notes the colors are artificial and added only for ambiance.