This class gathers the ‘skip’, ‘back’, ‘jump’, ‘rewind’, ‘continue’ and ‘break’ expressions which are used inside of the ‘cursor’ and ‘repeat’ (loop) expressions.

Look at the ‘cursor’ expression Ruote::Exp::Cursor for a discussion of each of those [sub]expressions.

The expression that understand commands are ‘cursor’, ‘repeat’ (‘loop’) and ‘iterator’. ‘concurrent_iterator’ does not understand commands since it fires all its branches when applied.

:ref => ‘tag‘

It‘s OK to tag a cursor/loop/iterator with the :tag attribute and then point a command to it via :ref :

  concurrence do

    cursor :tag => 'main' do
      author
      editor
      publisher
    end

    # meanwhile ...

    sequence do
      sponsor
      rewind :ref => 'main', :if => '${f:stop}'
    end
  end

This :ref technique may also be used with nested cursor/loop/iterator constructs :

  cursor :tag => 'main' do
    cursor do
      author
      editor
      rewind :if => '${f:not_ok}'
      _break :ref => 'main', :if => '${f:abort_everything}'
    end
    head_of_edition
    rewind :if => '${f:not_ok}'
    publisher
  end

this example features two nested cursors. There is a "_break" in the inner cursor, but it will break the main ‘cursor’ (and thus break the whole review process).

:ref works with the ‘iterator’ expression as well.