Can't store references to nodes in visitor

[tommaisey]

Hi, I'm trying to do some analysis/searching of Lua code with full_moon and I find I can't easily store references to nodes in a Visitor. I was looking at the syn crate and they have annotated their Visitor trait with the lifetime of the AST, meaning that this is allowed. Is it something you'd consider for full_moon?

[Kampfkarren]

Possibly! I'm okay with this at first glance.