Zohaib Rauf

The Option/Maybe monad is very common in FP languages. I don't know if it's native in Elixir, but apparently it's pretty easy to implement: http://www.zohaib.me/monads-in-elixir-2/#maybe There are lots of ways to conceptualize monads. I think "functors that flatten" is accurate, but is just one way.

An idiomatic Erlang/Elixir implementation of validation for a binary format would also give you decoding for free — see e.g. https://zohaib.me/binary-pattern-matching-in-elixir/. So I guess it's the encoding part that's unique to how Prolog works. Which makes sense; my understanding is that in Prolog, insofar as a function encodingOf(A, B) is defined by using A and B on either side of a bind expression to equate B as the encoding of A, if encodingOf(A, knownEnc) would act as a parser for knownEnc, then encodingOf(knownDec, B) would act as an encoder for knownDec — essentially swapping the question "what would this parse to" given an encoded binary, for "what would parse to this" given a decoded term. Erlang can't do exactly that — a given variable's "bound-ness" is determined during compilation, and head-clause variables can't be indeterminately bound — but if it could, then you would indeed get an encoder for the same format "for free", since binary-pattern matching in Erlang becomes a binary-building expression depending on whether the variables in the expression are bound or unbound. (Now I'm curious how hard it would be to add indeterminately-bound compile-time function polymorphism to Erlang — i.e. generating bytecode for the powerset of bound-ness-es of the variables in the head clause, only where at least one generates valid bytecode, probably name-mangled with a bitfield suffix of said bound-ness-es; and then being able to bind function parameters from such…

I would complement it with: - Scott Wlaschin's Railway Oriented Programming (ROP): https://fsharpforfunandprofit.com/rop/ and https://fsharpforfunandprofit.com/posts/recipe-part2/ - Scott Wlaschin's The "Map and Bind and Apply, Oh my!" series at https://fsharpforfunandprofit.com/series/map-and-bind-and-apply-oh-my.… and its concept of an "elevated world". - And for Elixir Programmers, Zohaib Rauf's "Railway Oriented Programming in Elixir" at https://zohaib.me/railway-programming-pattern-in-elixir/ based on Scott Wlaschin stuff. - https://wiki.haskell.org/All_About_Monads. The introductory part (7 first pages of the pdf). - Brian Beckman: Don't fear the Monad https://www.youtube.com/watch?v=ZhuHCtR3xq8 - Philip Wadler's "Monads for Functional Programming" at http://homepages.inf.ed.ac.uk/wadler/papers/marktoberdorf/baastad.pdf - HN comment: https://news.ycombinator.com/item?id=16446139 ROP is a good way to introduce the Either monad without ever talking about monads, functors and co. Moreover it is highly useful.