type-level programming

A 1987 talk in which John Backus, creator of Fortran, presents function-level programming and the FL language, a successor to his FP work. It is an archival recording with links to the related paper.

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.

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.

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.

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.

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

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.

Aditya Siram introduces ATS, a statically typed ML-like language that compiles to C and offers type-safe pointer arithmetic and a full proof language. The Strange Loop talk shows off C interop, concurrency and verification features with non-trivial examples.

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.

Felienne Hermans presents Hedy, a gradual programming language for teaching kids that moves through levels from almost no syntax toward full Python. The talk covers why error messages and syntax are scary for beginners.

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.

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.

Felienne Hermans argues that Excel is the world's most popular programming language and shows how spreadsheets work as a pure functional language. She implements a few mathematical problems in spreadsheet formulas to illustrate why they are so powerful and approachable.

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.

Jon Purdy's Stanford EE380 seminar giving an overview of concatenative programming, from function composition theory and history down to low-level implementation and correctness benefits.

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.

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.

A 1995 Sun Microsystems film about the Self programming language, a prototype-based Smalltalk relative, showing its live, graphical programming environment.

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.

Ahmon Dancy of Franz Inc explains low-level programming in Common Lisp, including off-heap data structures used in AllegroGraph to manage memory outside the garbage collector.

A roughly ten-minute demo of Microsoft's Intentional Programming research system, showing its editor and an unusual way of working with code. It is the first of two clips cut from a longer video.

A one-minute clip of Peter Norvig saying that Google found programming contest success correlates negatively or poorly with job performance. The description links to a blog post discussing it.

A panel from the Lang NEXT 2014 conference on systems programming in 2014 and beyond. Language designers including Bjarne Stroustrup and Rob Pike discuss the topic, including C++ header compile times.

Part 2 of an old Microsoft Research demo of Intentional Programming, showing the compiler side of a system that stores programs as abstract structure rather than text. The uploader says the companion editor clip is clearer.

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.

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.

Felienne Hermans's Strange Loop keynote on the history and pedagogy of teaching programming. She questions exploration-only approaches like Logo and discusses research supporting explicit instruction and rote practice.

A SXSW talk by W Watson that uses Lacanian psychoanalysis, with nods to Zizek, to critique popular programming languages. It argues that people choose and defend languages for emotional and ideological reasons rather than rational ones.

Shriram Krishnamurthi's PWLConf 2019 talk on the formal notion of expressive power of programming languages, based on Felleisen's paper. It explains how to tell when a feature adds power by whether emulating it requires global rewriting.

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.

Timothy Daly, an original author of the Axiom computer algebra system, talks about turning a large Common Lisp codebase into a literate program. He argues code should be written as readable manuals, and the talk was given at Write the Docs 2013.

Kevlin Henney argues that procedural programming never went away despite later paradigms such as OO and functional. He traces the history of structured programming and shows where procedural thinking still lives in modern code and why it matters for readability.

The first part of a series on programming in Jai, Jonathan Blow's in-development language. It covers compiling, writing hello world and using code from other files.

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.

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.

Aaron Hsu explains why programmers often find APL harder to learn than people with no programming background. He identifies eight patterns that contrast traditional software engineering practice with APL practice, starting from Ken Iverson's language design principles.

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.

Steven G. Johnson, MIT professor and FFTW co-author, gives a JuliaCon 2019 keynote on metaprogramming and staged programming in Julia, showing how it enables high-performance numerical code and when not to use macros.

Jim Weirich's RubyConf 2012 talk derives the Y combinator step by step, live-coding in Ruby lambdas. It builds up an understanding of functional programming and lambda calculus from first principles.

Andrew Kelley, creator of Zig, introduces the language at the Recurse Center's Localhost series in 2018. He covers its goals of robustness, optimality and clarity, C interop, cross-compilation and explicit allocators.