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I've tried in Rust, and it requires a return definition, as do most mainstream functional languages. Also, mainstream functional languages aren't truly mainstr

• igouy 9y ago
  let rec factorial n = if n = 0 || n = 1 then 1 else n * factorial (n - 1) F#
  • mrkgnao 9y ago
    Haskell: factorial n = if n < 2 then 1 else n * factorial (n - 1) I think the OCaml version will look almost exactly like the F# one.
• mrkgnao 9y ago
  I'm pretty sure that's just "administrative" and imposed by the syntax (e.g. think Java/C++ function declaration syntax), instead of being something the compiler can't infer. Thanks for clearing this up, though.
  • steveklabnik 9y ago
    It was a design decision, yes. We could infer them if we wanted to, but we don't.