Investigate -no-indent compiler flag

[l-kent]

Mandating the -no-indent compiler flag so that braces are necessary and formatting is more consistent may be worthwhile, but this will require a large formatting pass.

https://docs.scala-lang.org/scala3/reference/other-new-features/indentation.html

[katrinafyi]

With this compiler flag, what does the compiler do with valid brace syntax that has inconsistent indentation? It would be nice if this code was accepted as valid (for easier copy pasting etc).

[l-kent]

I believe it gives a warning

[utting]

Sounds good to me - will help to keep code more consistent and readable with many authors.
It is interesting that it still reports some indentation errors when -no-indent is turned on, and indentation suggests that some braces seem to be missing. This is a good feature I think.

[katrinafyi]

For those curious, these syntaxes remain valid with no-indent. This may or may not surprise you.

def f =
  "fdsajio" + 3

List(1).map { x =>
  println(x)
  x + x
  x
}

Option(10) match {
  case Some(_) =>
    println("hi")
    println("hi")
    2
  case None =>
    4
}

List(Option(10)).collect {
  case Some(_) =>
    println("hi")
    println("hi")
    2
  case None =>
    4
}

With no-indent, this syntax is parsed differently and now fails due to type errors:

List(1).map(x =>
  println(x)
  x + x
  x
)