module Net::IMAP::StringPrep

def check_prohibited!(string,

is raised (it does not affect behavior).
+profile+ is an optional string which will be added to any exception that

raise a BidiStringError.
Also checks bidirectional characters, when bidi: true, which may

ProhibitedCodepoint describing the first matching table.
Checks +string+ for any codepoint in +tables+. Raises a 
def check_prohibited!(string,
                      *tables,
                      bidi: false,
                      unassigned: "A.1",
                      stored: false,
                      profile: nil)
  tables  = Tables::TITLES.keys.grep(/^C/) if tables.empty?
  tables |= [unassigned] if stored
  tables |= %w[C.8] if bidi
  table   = tables.find {|t|
    case t
    when String then Tables::REGEXPS.fetch(t).match?(string)
    when Regexp then t.match?(string)
    else raise ArgumentError, "only table names and regexps can be checked"
    end
  }
  if table
    raise ProhibitedCodepoint.new(
      table, string: string, profile: profile
    )
  end
  check_bidi!(string, profile: profile) if bidi
end