Breaking Changes
Added HighlighterInterface::highlightAreas()
Custom highlighters implementing the HighlighterInterface need to implement the highlightAreas() method. The method expects a string value and an array of area markers and has to highlight these areas of the passed string in their own way and return the highlighted result.
You may want to use HighlighterHelper::processAreas() to normalize and validate the areas array.
If your custom highlighter extends the AbstractStringHighlighter, you don't have to do anything, the method is already implemented.