Freer Arrows and Why You Need Them in Haskell

2025/06/13 by VanDomelen, Grant, Shen, Gan, Kuper, Lindsey +1
#FOS: Computer and information sciences #Programming Languages (cs.PL)

paper · doi:10.48550/arxiv.2506.12212

Abstract

Freer monads are a useful structure commonly used in various domains due to their expressiveness. However, a known issue with freer monads is that they are not amenable to static analysis. This paper explores freer arrows, a relatively expressive structure that is amenable to static analysis. We propose several variants of freer arrows. We conduct a case study on choreographic programming to demonstrate the usefulness of freer arrows in Haskell.

Citations

• Efficient, Portable, Census-Polymorphic Choreographic Programming
• Ozone: Fully Out-of-Order Choreographies
• Alice or Bob?: Process Polymorphism in Choreographies
• Software for "How to Bake a Quantum Pi"
• Shades of Iteration: from Elgot to Kleene
• Pirouette: Higher-Order Typed Functional Choreographies
• From C to Interaction Trees: Specifying, Verifying, and Testing a Networked Server
• One Monad to Prove Them All
• Notions of Computation as Monoids
• Generalising monads to arrows
• Verifying an HTTP Key-Value Server with Interaction Trees and VST

Related

• Accessible bridge between category theory and functional programming
• Evaluating Linear Functions to Symmetric Monoidal Categories
• Pattern Runs on Matter: The Free Monad Monad as a Module over the Cofree Comonad Comonad
• Multi-Level Languages are Generalized Arrows
• Free Foil: Generating Efficient and Scope-Safe Abstract Syntax