Functional Valhalla?

An exploration of flat and dense memory layouts in functional programming languages, motivated by the performance costs of pointer-rich data structures on modern hardware. The post surveys which functional languages support arrays of records with flat memory layouts: F# fully supports it (including records with pointer fields), Haskell supports it via the Data.Vector.Unboxed library (with caveats), and Clean supports it natively. Languages like OCaml, SML, Erlang/Elixir, and Scala appear to lack this support. The post also discusses implementing flat layouts as libraries in Scheme and Common Lisp, and concludes that functional language support for cache-efficient memory layouts remains limited compared to imperative languages.