Are you sure you want to do this?

It seems like you should really handle sentances that end with other punctuation, or quoted sentances, etc. But the problem becomes rapidly more complicated when you try.

A simpler option is just to append ... to the truncated string, or at most to always cut off the last word in case its partial. People know whats going on when they see a truncated sentance and ..., whereas if you silently cut off something you may change the meaning without giving any clue that you've done so.

qq