Backwards label on brackets

[schneems]

This label seems backward:

DeadEnd: Unmatched `]` detected

file: /tmp/scratch.rb
simplified:

      1  def foo
    ❯ 2    foo = [ 1,1,1
      3  end

The problem isn't an unmatched "]", the problem is an unmatched "[", to fix it a "]" is needed.

$ ruby -wc /tmp/scratch.rb
/tmp/scratch.rb:3: syntax error, unexpected `end', expecting ']'

I think we should change the label/banner to be

Unmatched `[` it appears `]` is missing

The cases I know off the top of my head for these single character chases are:

• Square brackets []
• Curly brackets {}
• Parens ()
• Pipe chars || (but these are not directional)

My thought would be to make a hash map from one char to it's logical inverse and use that for the display. Also, all of this banner/label logic is bundled together in DisplayInvalidBlocks. It might be worth making the banner/label stuff it's own class and have it be consumed by DisplayInvalidBlocks instead.