A string representation of the line break strategy, suitable for being saved and loaded via saveProfile() and loadProfile(). parseLineBreakStrategy() should be able to parse it.

Determine where the next line break should occur, or return a null index if no line break should occur (e. g. because there aren’t enough tokens).

If the first element of the returned value [i, lb] (index, line break) exists, it means that tokens 0..i should be taken from the elements and written out; if lb is true, a LineBreak should be inserted there first.

To clarify, the caller of this method should react to the returned value [i, lb] like this:

• If i is null, do nothing.

• If lb is true, take the elements up to (but not including) i and write them out (removing them from the queue), then write out a line break.

  Equivalently, insert a LineBreak (ceylon.formatter::FormattingWriter.LineBreak) into the queue at index i, then write out the elements up to and including i.

  Afterwards, the element that was previously elements[i] is now the first queued element.

• If lb is false, take the elements up to and including i and write them out (removing them from the queue). (Do not write out an explicit line break.)

  Afterwards, the element that was previously elements[i + 1] is now the first queued element.

Usually, when an element makes the line too long, its index and true is returned. The false case is necessary for a) existing explicit line breaks, and b) multi-line string literals that don’t make the line too long, but still break the line (but not with an explicit extra line break).