The compiler should warn when ";" is accidentally used instead of ":" at the end of a line

[smarter]

Spot the bug:

object A;
  def foo = 1

A.foo // error: value foo is not a member of A

On a French keyboard, ; and : are on adjacent keys, so this is an easy mistake to make and hard to spot given how similar both of these characters look. When omitting the : we get a warning, but no such warning appears when the line ends with a ;:

object A
  def foo = 1

-- Warning: --------------------------------------------------------------------
2 |  def foo: Int = 1
  |  ^
  |  Line is indented too far to the right, or a `{` or `:` is missing

[som-snytt]

It could lint any semi that is not required for parsing. The optional semi before a guard in a for loop may be controversial enough to occasion fisticuffs in the break room.