CSV::Parser#prepare_strip

# File tmp/rubies/ruby-3.3.0/lib/csv/parser.rb, line 526
def prepare_strip
  @strip = @options[:strip]
  @escaped_strip = nil
  @strip_value = nil
  @rstrip_value = nil
  if @strip.is_a?(String)
    case @strip.length
    when 0
      raise ArgumentError, ":strip must not be an empty String"
    when 1
      # ok
    else
      raise ArgumentError, ":strip doesn't support 2 or more characters yet"
    end
    @strip = @strip.encode(@encoding)
    @escaped_strip = Regexp.escape(@strip)
    if @quote_character
      @strip_value = Regexp.new(@escaped_strip +
                                "+".encode(@encoding))
      @rstrip_value = Regexp.new(@escaped_strip +
                                 "+\\z".encode(@encoding))
    end
    @need_robust_parsing = true
  elsif @strip
    strip_values = " \t\f\v"
    @escaped_strip = strip_values.encode(@encoding)
    if @quote_character
      @strip_value = Regexp.new("[#{strip_values}]+".encode(@encoding))
      @rstrip_value = Regexp.new("[#{strip_values}]+\\z".encode(@encoding))
    end
    @need_robust_parsing = true
  end
end