PP::PPMethods#pp_hash_pair

# File tmp/rubies/ruby-3.4.1/lib/pp.rb, line 303
def pp_hash_pair(k, v)
  if Symbol === k
    sym_s = k.inspect
    if sym_s[1].match?(/["$@!]/) || sym_s[-1].match?(/[%&*+\-\/<=>@\]^`|~]/)
      text "#{k.to_s.inspect}:"
    else
      text "#{k}:"
    end
  else
    pp k
    text ' '
    text '=>'
  end
  group(1) {
    breakable
    pp v
  }
end