Text Boundaries -- BreakIterator

Break Iterator also provides a C language API.

• Line boundaries
  -- used for line-wrapping
  -- correctly handles punctuation and hyphenated words.
• Sentence boundaries
  -- handles periods within numbers and abbreviations
  -- handles trailing punctuation marks such as parentheses.
• Word boundaries
  -- for search and replace functions
  -- for selecting words with a double mouse click
• Character boundaries
  -- handles combining characters

ReadMe for IBM's International Classes for Unicode, API Overview