Odd newline and parenthesization rules

[wren-lang]

Odd newline and parenthesization rules

[kmarekspartz]

Not sure what's changed here, but this problem still remains with newer syntax. This works:

class Set {
  // ...
  -(that) {
    // Set minus
    return new Set(
      _list.where { |element|
          !that.contains(element)
      })
  }
}

This fails:

class Set {
  // ...
  -(that) {
    // Set minus
    return new Set(
      _list.where { |element|
          !that.contains(element)
      }
    )
  }
}

Error message:
[example/set.wren line 8] Error on newline: Expect ')' after arguments.

[munificent]

Ah, yes. So the issue is that after it parses:

      _list.where { |element|
          !that.contains(element)
      }

It's looking for either a , to indicate the next argument, or ) to indicate the end of the argument list. Instead, it sees a newline.

My personal preference is to put the ) right after the }, which sidesteps this issue. But I think it may be more usable for others to ignore a newline here.

I'm trying to think if that will cause any unintended side-effects. I don't think so, but it probably does imply we'd also want to ignore newlines before ) in a parenthesized expression, and ] in a list literal, etc.

That makes me wonder if we should change the overall rules for ignoring newlines. I think they've sort of grown hairier over time. One idea I had was that the parser could keep track of if it's in statement or expression context, and discard all newlines when in the latter.