type classes

Edward Kmett speaks at the Boston Haskell meetup about type classes and the design tradeoffs of global coherence compared with other approaches to implicit instances. It covers why uniqueness of instances matters for reasoning and refactoring.

Simon Peyton Jones's first lecture on types in Haskell from the Oregon Programming Languages Summer School 2013. It covers type classes and how they relate to OOP, subtyping and polymorphism.

The Michigan TypeScript group shows the Doom engine running entirely inside the TypeScript type system. It is open source, and two follow-up videos cover why and how they did it.

A Channel 9 conversation recorded at GOTO 2012 between Anders Hejlsberg (TypeScript) and Lars Bak (Dart). They discuss the two languages and different approaches to making JavaScript development safer, including runtime type checking.

Edwin Brady, creator of Idris, presents Idris 2 and demonstrates type-driven development, where the compiler assists by filling holes and suggesting implementations from types.

Edwin Brady presents Idris 2, a rewrite of the Idris dependently typed language, and shows type-driven development in practice. The demos show the compiler filling in whole functions from their types.

José Valim's ElixirConf US 2023 closing keynote on the foundations of the Elixir type system, covering set-theoretic types and gradual typing with strong arrows.

Aaron Hsu's FnConf18 talk asks whether APL needs a static type system. He argues that APL's expressiveness and rapid iteration already deliver the benefits usually credited to types.

David Christiansen gives a Strange Loop 2018 introduction to dependent types, where one language serves for both compile-time and run-time code and programs unite with proofs. It draws on his book The Little Typer.

Edwin Brady, creator of Idris, introduces type-driven development in a dependently typed language. He shows types being written first and programs derived with interactive editing, then extends beyond simple examples to programs that interact with users and networks.

A London Haskell talk on the algebra of algebraic data types, showing how sum and product types behave like arithmetic. It frames types as numbers obeying algebraic laws.

ElixirConf EU 2023 talk by Giuseppe Castagna and Guillaume Duboc on bringing set-theoretic types to Elixir, and the benefits such a type system could offer such as catching bugs.

Philip Wadler's Strange Loop talk on Propositions as Types, the link between logic and computation (the Curry-Howard correspondence). He traces its history through Church, Godel and Turing and shows how it shaped theorem provers and programming languages.

Philip Wadler's Lambda Days talk on propositions as types, the link between logic and computation that underlies theorem provers and programming language design.

Matthias Felleisen's keynote uses weather prediction as an analogy for type systems, arguing they forecast problems so you can act on them. It draws on his experience developing Typed Racket.

Nadia Polikarpova's Strange Loop talk on program synthesis driven by refinement types, as in Synquid. It shows how rich type specifications can be turned into verified, executable code.

An interview with Anders Hejlsberg, lead architect of TypeScript, about porting the TypeScript compiler to Go. He covers the 10x type-checking speedup, lower memory use, and why Go was chosen.

Raymond Hettinger explains Python's dataclasses module, showing the problem it solves and its key design decisions. He places it in a progression from tuples and dicts through named tuples and attrs.

CuriousMarc inspects a newly arrived Teletype Model 19, an early military unit built around a Model 15 keyboard and printer, after an initial rough cleaning. It is the first part of a restoration series and touches on 5-bit Baudot code.

Professor Brailsford of the University of Nottingham describes how the university set out to print its own mathematics exam papers in the 1980s. The story centers on getting a Mergenthaler Linotron 202 typesetter to work with their own software.

A Ben Heck Show episode tearing down the Nintendo PlayStation prototype, one of the rarest consoles ever, with its owners Terry and Dan Diebold. Part 2 then gets it working again.

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.

Jiahao Chen's JuliaCon 2017 talk argues that vector transposes should be taken seriously in type systems and linear algebra libraries. It explains why treating vectors as matrices causes trouble in languages.

Scott Wlaschin shows how statically typed functional languages, using F# examples, can model a business domain so that invalid states cannot be represented. The type system acts almost like an instant unit test at compile time.

Tom 7's pilot episode of a series that plays with type systems and absurd programming, presented as a parody of the GPL v3 license. It mixes a typesetting experiment with a long, story-driven intro on the origin of TeX. Source code and papers are linked from the author's site.

Simon Peyton Jones presents linear types for Haskell, showing how practical linearity can fit into a higher-order polymorphic language. The talk covers motivations such as resource handling and relates the ideas to Rust.

At CppCon 2017 Herb Sutter presents his work on evolving C++ through compile-time code generation, including metaclasses and reflection. The aim is to make the language both more powerful and simpler by letting programmers express intent directly.

CuriousMarc connects a restored 1930 Model 15 Teletype to a Linux machine and uses it as a terminal, after commenters requested it. The video shows the challenges of linking a 5-bit mechanical device to a modern OS.

The SILE author's FOSDEM 2015 talk introducing SILE, a TeX-inspired typesetting system with frame-based layout, Unicode, OpenType and a Lua-based extensible design.

Anders Hejlsberg introduces the native port of the TypeScript compiler, written in Go, which promises roughly 10x faster tooling. He demos compiling VS Code and explains where the speedup comes from.

Yaron Minsky of Jane Street gave this talk to Harvard's OCaml-based CS51 class in 2010. It collects advice on being an effective ML programmer in an industrial setting.

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.

Douglas Crockford's Nordic.js 2014 talk on 'the better parts' of JavaScript and programming in general. He argues against `this`, `new` and ES6 classes, and for classless, composition-based object patterns, with some broader remarks on building better structures for the future.

Richard Feldman's GOTO Copenhagen 2022 talk on why dynamic languages like Python, Ruby, PHP and JavaScript rose in the 1990s and why each now has a popular static type checker. It argues that modern static typing recovers the advantages that made dynamic languages attractive.

Bjarne Stroustrup's keynote at Going Native 2012 covers the ideas behind C++11, including using types to prevent errors and simplifying code with the STL.

Richard Feldman's elm-conf talk on designing models so that bugs from impossible application states cannot occur, using Elm's compiler and types. It demonstrates techniques for making invalid states unrepresentable.

A documentary on the last day the New York Times was printed with linotype machines in 1978, following the process from the newsroom to the press. It marks the move to computerized typesetting.

Dr. Sarah Hallberg argues in a TEDx talk that type 2 diabetes can be treated and potentially reversed through diet, especially by restricting carbohydrates. TED flagged the talk as outside its guidelines and warned against taking it as medical advice.

Bill Hammack of engineerguy uses slow motion video to show how the IBM Selectric typewriter works. He focuses on its fully mechanical digital-to-analog converter, which turns key presses into rotation of the type ball.

Tom Wildenhain's SIGBOVIK 2018 presentation of WordTeX, a Microsoft Word template that mimics LaTeX typesetting output. It is a joke research project executed with serious effort.