module Net::IMAP::StringPrep::SASLprep

def saslprep(str, stored: false, exception: false)

information.
Unicode 3.2, and not later versions. See RFC3454 ยง7 for more
For \StringPrep and the \SASLprep profile, "unassigned" refers to
When +stored+ is +true+, "unassigned" codepoints will be prohibited.

+true+, a StringPrepError describing the violation will be raised.
By default, prohibited strings will return +nil+. When +exception+ is

RFC4013 of the StringPrep algorithm RFC3454.
Prepares a UTF-8 +string+ for comparison, using the \SASLprep profile 
def saslprep(str, stored: false, exception: false)
  return str if ASCII_NO_CTRLS.match?(str) # incompatible encoding raises
  str = str.encode("UTF-8") # also dups (and raises for invalid encoding)
  str.gsub!(MAP_TO_SPACE, " ")
  str.gsub!(MAP_TO_NOTHING, "")
  str.unicode_normalize!(:nfkc)
  # These regexps combine the prohibited and bidirectional checks
  return str unless str.match?(stored ? PROHIBITED_STORED : PROHIBITED)
  return nil unless exception
  # raise helpful errors to indicate *why* it failed:
  tables = stored ? TABLES_PROHIBITED_STORED : TABLES_PROHIBITED
  StringPrep.check_prohibited! str, *tables, bidi: true, profile: "SASLprep"
  raise InvalidStringError.new(
    "unknown error", string: string, profile: "SASLprep"
  )
rescue ArgumentError, Encoding::CompatibilityError => ex
  if /invalid byte sequence|incompatible encoding/.match? ex.message
    return nil unless exception
    raise StringPrepError.new(ex.message, string: str, profile: "saslprep")
  end
  raise ex
end