You can do functional programming in Lisp, but even the wiki page for GOAL says ...

pjmlp · on Jan 18, 2015

I have a problem with modern notions of purely functional.

My first functional programming language was Caml Light, back in 1996. Followed by Prolog and eventually Lisp.

All alongside traditional lambda calculus and logic proofs, with ocasional references to a programming language called Mirada.

So for me, Lisp is functional programming and I don't buy into this modern notion that only Haskell is the poster child of FP.

Retra · on Jan 19, 2015

I looks like alayne is using 'purely functional' to mean Pure + Functional, but you are using it to mean Everything is an Expression / First-class functions, etc.. The functional paradigm.

Lisp is definitely a functional language. It's just not as pure as Haskell, which is the poster child for Maximally Pure FP, if not for the functional style.

pjmlp · on Jan 19, 2015

Hence why I made the reference to Miranda.

We were already doing functional programming while Haskell was still using diapers.

Retra · on Jan 20, 2015

Well, yes. Haskell is heavily inspired by Miranda. Haskell was just managed in a way that allowed it to become very popular.