[gregwebs]

Functional programming is immutable by default. TypeScript and many other typed languages don't really stop you from clobbering things, particularly with concurrency. Rust does. But immutability with GC is a lot easier to use than Rust if you don't need the performance of Rust.

[pjmlp]

That is only true since people started equating FP with Haskell.

OCaml as the discussion subject on this thread, allows for mutable data structures, and I am old enough to have been taught Lisp as one possible avenue for FP.

[nrlucas]

They have mutability, but it's generally not encouraged. The default is immutability.

[galangalalgol]

But what is functional besides haskell? Purescript? Elm I guess. Ocaml is not. It has for loops even. You can write pure functional ocaml but people don't. It mattered a lot less when it didn't have true concurrency, but now clobbering things in ocaml is quite possible.

[greener_grass]

Define functional?

Even Haskell is not functional in the strictest sense. It has unsafe IO. It can throw exceptions. Functions may not halt.

[phplovesong]

FP has nothing to do with mutability. You seem to lack a basic understanding what the common FP languages are, and what FP actully is.

[e12e]

StandardML (standard metalanguage), scheme?