I have just released the first version of the
TreeView package, which makes it easy to visualize the syntax tree of a Julia
Expression as a graph.
It is as simple as typing
using TreeView @tree x^2 + y^2
in an IJulia notebook.
You can see a couple of examples here.
This uses the nice
TikzGraphs package, so requires LaTeX to be installed on your system, as well as
pdf2svg. (See the README of
Apart from being useful for visualization purposes, it is also intended as a pedagogical example of how to walk a syntax tree and do basic metaprogramming.
Suggestions and Pull Requests are, of course, welcome.