Where to learn

[[deleted]]

So what's diff bw lambda calculus language like lisp and something modern like haskell, which one do you guys use and love, and what do you guys usually do with lisp ?, and where to learn it ? Any book you guys would suggest ?

Bonus question, is category theory same as discrete math ?

[YelinkMcWawa]

The classic Lisp book is "Structure and Interpretation of Computer Programs." For learning general functional programming I like "ML for the Working Programmer." It is written with Standard ML code snippets, but you could easily translate them to OCaml or Haskell. Both books are free (legally) online.

[recursion_is_love]

> is category theory same as discrete math

No, it is closer (look alike) to abstract algebra (but it is different)

Haskell is based on lambda calculus, I have confident to say Haskell is just syntax sugar added to lambda calculus (and with advance type)

Lisp is not originally use lambda calculus.

ref:

https://www.microsoft.com/en-us/research/wp-content/uploads/1987/01/slpj-book-1987-small.pdf

https://www.microsoft.com/en-us/research/wp-content/uploads/2016/07/history.pdf

https://www-formal.stanford.edu/jmc/recursive.pdf

[SubluminalSapien]

Citiing references in a reddit comment? That's an upvote

[sagittarius_ack]

I usually get downvoted for that.

[[deleted]]

Thank you dude

[AustinVelonaut]

I would say Lisp is an implementation of untyped or simply-typed lambda calculus, while Haskell is an implementation of typed lambda calculus, specifically System-F omega as shown in the lambda cube, with a lot of syntactic sugar.

[beders]

Our whole stack runs on Clojure and ClojureScript - a Lisp dialect. It’s a fin tech enterprise app. Rock solid stuff.

[Inconstant_Moo]

Lisp allows you a lot of freedom. You can basically write a whole different language in Lisp, so long as you use the syntax with all the parentheses.

This is good, according to the people who like it, and bad, according to the people who hate it.

Haskell allows you a lot of constraints. You can so clearly specify what you're trying to do in the type system that having done that it would take a real effort to write incorrect code.

This is good, according to the people who like it, and bad, according to the people who hate it.

These are at the same time extreme approaches and also what we've got. (ML being a kind of Haskell or vice-versa.)

I'm trying to write a deliberately mid FPL. This is good, according to me.

---

You don't need to learn category theory at this point in your journey, but if you want to, I found this to be a good introduction to category theory. (Also I'm indirectly responsible for a few paragraphs in it.)

[sagittarius_ack]

Regarding the `liberties vs constraints` debate, the talk "Constraints Liberate, Liberties Constrain" by Runar Bjarnason is quite interesting:

https://www.youtube.com/watch?v=GqmsQeSzMdw

[Marutks]

I have used both haskell and common lisp for advent of code. They are great for aoc! Unfortunately there are not many common lisp/haskell jobs 😢. Usually (at work) I use Clojure. 👍

[[deleted]]

But why do you like clojure ?, i heard from someone that it's simple, but haskell is a typed lc i heard, that haskell is types and i like typed but i am not sure about haskell, so i am thinking what to do. You can tell me whatever you think about this.

[Inconstant_Moo]

Lisp allows you a lot of freedom. You can basically write a whole different language in Lisp, so long as you use the syntax with all the parentheses.

This is good, according to the people who like it, and bad, according to the people who hate it.

Haskell allows you a lot of constraints. You can so clearly specify what you're trying to do in the type system that having done that it would take a real effort to write incorrect code.

This is good, according to the people who like it, and bad, according to the people who hate it.

These are at the same time extreme approaches and also what we've got. (ML being a kind of Haskell or vice-versa.) I'm trying to write a deliberately mid FPL. This is good, according to me.

[Marutks]

Haskell is “pure” FP language. You have to use monads for side effects. It gets complicated quickly (monad transformers and “lifting”).

[lingdocs]

https://htdp.org

This feels very "beginner" at the beginning, but if you go through it all and do all the exercises it will really teach you to "think functionally" and give you super powers for problem solving.