brendanzab

(** This is a demonstration of implementing interpreters in an extensible way
    that offers a partial solution to the expression problem. The idea is that
    the language can be extended with more features after the fact, without
    altering previous definitions. It also has the benefit of grouping the
    related extensions to the syntax and semantic domains together with the
    relevant evaluation rules in a per-feature way.

    This approach used is similar to the one described by Matthias Blume in
    {{:https://www.microsoft.com/en-us/research/video/records-sums-cases-and-exceptions-row-polymorphism-at-work/}
    Records, sums, cases, and exceptions: Row-polymorphism at work}.

AndrasKovacs

Lightweight region memory management in a two-stage language

• Intro
• Basics
  • Stage inference
• Regions
  • Bit-stealing
  • Using regions
• Eager regions

tttardigrado

data P = R | L | Seq P P | Loop P

data Tape = Tape [Int] Int [Int]

empty :: Tape
empty = Tape (repeat 0) 0 (repeat 0)

left :: Tape -> Tape
left (Tape (l:ls) v rs) = Tape ls l (v:rs)

brendanzab

data Bool { T, F }

data Nat { Z, S(n: Nat) }

def (n1: Nat).eq(n2: Nat): Bool {
    Z => n2.match {
        Z => T,
        S(_) => F,
    },
    S(n1) => n2.match {