type systems

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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.

An AWS re:Invent 2014 talk on the core distributed systems primitives behind AWS and Amazon.com, such as consensus, key-value stores and transactional logging. It describes how AWS builds large services from a few common building blocks.

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.

Chris Houser's Clojure/conj talk on why Clojure's exceptions destroy information as the stack unwinds, unlike Common Lisp's condition system, which can resume from the error site. He surveys the existing libraries that approximate conditions, explains why they don't compose with each other, and considers what a better design would look like.

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.

Timothy Roscoe of ETH Zurich delivers the joint USENIX ATC/OSDI 2021 keynote arguing that operating systems must reckon with modern hardware, which is a heterogeneous collection of processors, firmware and coprocessors rather than a simple machine. It shows how much runs below and beside Linux.

Joe Duffy's RustConf 2017 closing keynote on his experience at Microsoft building Midori, an operating system written in a Rust-like safe systems language. He covers the technical and cultural challenges of applying those lessons to Windows.

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.

Scott Wlaschin's NDC talk on using statically typed functional programming, F# in particular, to model a business domain. Types are used to represent the domain precisely and to encode business rules so that illegal states cannot be built, with the compiler acting as an instant unit test.

Richard Cook's short Velocity 2013 talk on resilience in complex adaptive systems, arguing systems operate near the edge of failure and that the surprise is how rarely they fail. He presents a model of how pressures push systems toward failure boundaries.

Dr. Richard Cook, a physician and patient safety researcher, presents his ideas on how complex systems fail, at Velocity 2012. He argues for designing for resiliency rather than trying to exhaustively handle every failure mode.

Peter Alvaro's Strange Loop 2015 talk argues that query languages let you state what you mean, and applies that to distributed programming. It covers Datalog, Dedalus and the Bloom lineage for reasoning about distributed systems.

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.

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.

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.

Joran Dirk Greef's Systems Distributed '23 talk on TigerStyle, the engineering methodology behind TigerBeetle. It covers designing safer systems in less time through up-front design, assertions, and deterministic simulation.

Optiver's Carl Cook explains how to build high-frequency trading systems in C++, where the critical path runs rarely but must be extremely fast. He covers techniques for low and predictable latency, including avoiding main memory and cache misses.

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.

Jeff Bonwick and Bill Moore, the creators of ZFS, present 'ZFS: The Last Word in File Systems' at the 2008 SNIA Software Developers' Conference. They explain the design, including copy-on-write, checksumming and avoiding the write hole.