URI::MailTo#check_to

# File tmp/rubies/ruby-4.0.0/lib/uri/mailto.rb, line 169
def check_to(v)
  return true unless v
  return true if v.size == 0

  v.split(/[,;]/).each do |addr|
    # check url safety as path-rootless
    if /\A(?:%\h\h|[!$&-.0-;=@-Z_a-z~])*\z/ !~ addr
      raise InvalidComponentError,
        "an address in 'to' is invalid as URI #{addr.dump}"
    end

    # check addr-spec
    # don't s/\+/ /g
    addr.gsub!(/%\h\h/, URI::TBLDECWWWCOMP_)
    if EMAIL_REGEXP !~ addr
      raise InvalidComponentError,
        "an address in 'to' is invalid as uri-escaped addr-spec #{addr.dump}"
    end
  end

  true
end