unpack_graphemes

# File activesupport/lib/active_support/multibyte/unicode.rb, line 80
      def unpack_graphemes(string)
        codepoints = string.codepoints.to_a
        unpacked = []
        pos = 0
        marker = 0
        eoc = codepoints.length
        while(pos < eoc)
          pos += 1
          previous = codepoints[pos-1]
          current = codepoints[pos]

          should_break =
            # GB3. CR X LF
            if previous == database.boundary[:cr] and current == database.boundary[:lf]
              false
            # GB4. (Control|CR|LF) ÷
            elsif previous and in_char_class?(previous, [:control,:cr,:lf])
              true
            # GB5. ÷ (Control|CR|LF)
            elsif in_char_class?(current, [:control,:cr,:lf])
              true
            # GB6. L X (L|V|LV|LVT)
            elsif database.boundary[:l] === previous and in_char_class?(current, [:l,:v,:lv,:lvt])
              false
            # GB7. (LV|V) X (V|T)
            elsif in_char_class?(previous, [:lv,:v]) and in_char_class?(current, [:v,:t])
              false
            # GB8. (LVT|T) X (T)
            elsif in_char_class?(previous, [:lvt,:t]) and database.boundary[:t] === current
              false
            # GB8a. Regional_Indicator X Regional_Indicator
            elsif database.boundary[:regional_indicator] === previous and database.boundary[:regional_indicator] === current
              false
            # GB9. X Extend
            elsif database.boundary[:extend] === current
              false
            # GB9a. X SpacingMark
            elsif database.boundary[:spacingmark] === current
              false
            # GB9b. Prepend X
            elsif database.boundary[:prepend] === previous
              false
            # GB10. Any ÷ Any
            else
              true
            end

          if should_break
            unpacked << codepoints[marker..pos-1]
            marker = pos
          end
        end
        unpacked
      end