Functional Programming in Swift

When people talk about functional programming in modern multi-paradigm languages, they usually mention Rust, Scala, or Kotlin. You rarely hear Swift being mentioned. This is odd, as one might argue that, of these languages, Swift places the strongest emphasis on functional programming.

In this talk, I will explain the core functional programming features of Swift, including its expressive type system, value types, and mutability control. Furthermore, I will discuss how Swift’s language design is influenced by the desire to create a language that addresses the whole spectrum from low-level systems programming up to high-level applications with sophisticated graphical user interfaces. Beyond the core language itself, functional programming also permeates Swift’s rich ecosystem of libraries. To support this point, I will outline some FP-inspired core libraries, covering concepts from functional data structures over functional reactive programming to declarative user interfaces.

Finally, I will briefly summarise practical considerations for using Swift in your own projects. This includes the cross-platform toolchain, the package manager, and interoperability with other languages.

Manuel Chakravarty

Twitter: @TacticalGrace

Manuel M T Chakravarty is a researcher and software developer with interests in programming languages, cryptography, and programming environments. He developed the interactive development environment Haskell for Mac — one of the first Swift apps on the Mac App Store. He is now working on the successor of Haskell for Mac, which leverages SwiftUI for cross-platform development. His current research work lies at the intersection of programming languages and cryptography with applications to open blockchains. Recent contributions cover smart contract and native asset support for UTxO ledgers, such as Cardano, as well as multi-party state channels. He has also published extensively on programming languages, compilers, and high-performance computing. He contributed to both the design and implementation of the Haskell programming language (most notably, type families, associated types, and the foreign function interface) as well as several Haskell tools and open source libraries. He is currently a functional programming expert at Tweag and a researcher & architect of smart contract technology at IOG (formerly, IOHK). Before that he was an Associate Professor at UNSW Sydney.

Slides

chakravarty.pdf