How close are the semantics to F#? For example OCaml has bucklescript which produces reasonable looking JavaScript but doesn’t always follow the language semant

How close are the semantics to F#? For example OCaml has bucklescript which produces reasonable looking JavaScript but doesn’t always follow the language semantics, and js_of_ocaml which produces horrid JavaScript (it compiles from 32-bit OCaml bytecode to js, and fakes the OCaml memory layout of objects by using arrays with their first element being the tag of the object, so e.g. a float is represented in js as [<magic number>, <the actual float>]). Similarly, Common Lisp has something called parenscript which compiles a lispy syntax to js but e.g. uses JavaScript arrays for its lists (so you don’t have a cons function).