Pitch: Multi-statement if/switch/do expressions

[cal (Cal Stephens)]

return returning from the "outer" function closure like in Rust, Ruby, Kotlin and Scala

@Paul_Cantrell

Rust allows it:

fn foo(array: &[i32]) -> i32 {
  let value = if array.is_empty() {
    0
  } else {
    return 3  // ✅ returns from function
  };
  // do stuff with value
}

Ruby allows it:

def foo(array)
  value = if array.empty?
    0
  else
    return 3  # ✅ returns from function
  end
  # do stuff with value
end

Kotlin allows it:

fun foo(list: Collection<Int>): Int {
  var value = if (list.isEmpty()) {
    0
  } else {
    return 3  // ✅ returns from function
  }
  // do stuff with value
}

Scala allows it:

def foo(list: List[Int]): Int = {
  var value = if (list.isEmpty) {
    0
  } else {
    return 3  // ✅ returns from function
  }
  // do stuff with value
}

Hmm, this is a really valuable look at how this works in peer languages. I had previously been supportive of using return over then, but seeing how this works in so many other languages makes me reconsider. While we aren't beholden to the design choices of other languages, it seems like important signal -- this probably tells us at least a little on how people will intuitively expect this to work.

So I'm definitely seeing the appeal of using then instead, to avoid the potential confusion and diverging from how this works elsewhere.