base this on AbstractTrees.jl

[nsajko]

It seems like it would make a lot of sense to base this package on the AbstractTrees.jl interface. That is, require users to implement the AbstractTrees.jl interface and any additional functions that are required after that. So some of the functions from this package could be made internal, users wouldn't have to add any methods to those functions. That would enable more interoperability across the ecosystem. Also, TBH, I'm not sure if this package is even necessary given that AbstractTrees.jl already exists?

https://juliahub.com/ui/Packages/General/AbstractTrees

[nsajko]

Wouldn't work because AbstractTrees.jl can't distinguish between a constant/variable and a nullary expression.