The ggdiagram package takes an object-oriented approach to making diagrams (using S7) and plots the results using ggplot2.
This package is in a very preliminary state. It has some structural beams and a bit of plumbing but is not yet capable of fulfilling its eventual purpose.
My motivation in making ggdiagram was to find a way to approach the functionality of TikZ but with the flexibility and convenience R. The ggdiagram package is built atop S7 is integrated with ggplot2, making use of ggtext, ggforce, and ggarrow.
The ggdiagram package is not a replacement for the standard ggplot2 functions. The underlying "grammar" of ggplot2 is well designed for visualizing data. The ggdiagram functions are designed creating a small number of objects that are interrelated. If anything, they can be thought of as extensions of ggplot2::annotate.
You can install the development version of ggpathdiagramr like so:
remotes::install_github("wjschne/ggdiagram")