Horizontal DAG graph

[LucasLeRay]

I use Diagon for comments in my source code, so the vertical orientation is inconvenient. Is it possible to have horizontal orientation?

horizontal:
┌─┐┌─┐
│a->b|
└─┘└─┘

vertical:
┌─┐
│a│
└┬┘
┌▽┐
│b│
└─┘