[Smaug123]

(I wrote this without realising that you specifically meant "syntax for functional programming". Sorry.)

Syntax is fairly different but the concepts are broadly similar. Rust has many of the same nice things as F# does, like "if" as an expression rather than a statement, algebraic data types, mutability declared as a keyword, etc. In fact Rust is much stricter with the "declared mutability" thing, because in F# you can use an immutable reference to a mutable object to mutate the object.

The really big paradigm difference I found as an F# person when starting to learn Rust was the lack of guaranteed tail-call optimisation, meaning that Rust kind of wants you to avoid recursive functions. I also find it much more annoying to write sequences ("Iterators") in Rust than in F# (where the `seq` computation expression makes everything ludicrously easy at the cost of some oddly bad performance sometimes). F#'s anonymous interface implementations are also really handy, but Rust's situation there is at least no worse than C#.