melvic-ybanez

What I Didn't Know about Functional Programming until 2020

1. Programming using a series of transformations and aggregations, something I've been doing for years, is known as programming in the map/reduce style.
2. The more abstract the type is, the greater its cardinality, and the smaller the set of operations it supports. So make use of universal quantifiers, particularly by implementing fully parametric functions. They guide you on how to implement their term-level definitions by narrowing down the number of possible implementations. In other words, the type system of Scala (or Haskell, for that matter) is not only great for capturing compile-time errors, but is also capable of leading you to the correct solution.
3. You can encode union types by combining different Scala features such as type constructors, subtyping and implicits, and by taking advantage of the Curry-Howard Isomorphism and De Morgan's Laws for neg

alahijani

module Euclid

import Syntax.PreorderReasoning

%default total

Divides : (divisor, dividend : Nat) -> Type
Divides d n = (q : Nat ** (n = q * d))

data Direction = LTR | RTL

pdarragh

Approachable PL Papers for Undergrads

On September 28, 2021, I asked on Twitter:

PL Twitter:

you get to recommend one published PL paper for an undergrad to read with oversight by someone experienced. the paper should be interesting, approachable, and (mostly) self-contained.

what paper do you recommend?