consider:

my const varname = expression

things to notice:

- 'my' and 'const' are right associative, meaning they bind to what's to the
  right side of them.
- '=' and 'expression' are left associative
- '=' is the root of the tree

things to think about:
- is 'varname' is right associative, or does its association matter?
- as a tree, how is this laid out? Is it a simple linked list of left/right
  values and then one of the nodes in it knows that it's the parent, OR, are
  there left/right children, and then links to the parent nodes (in the case
  of a binary tree).
    - if it is a binary tree (likely), then how are left and right
      associations represented on it? Can they be represented in a consistent
      way?
    - We might consider the tree to be like:
                                  =
                                  |
                          varname/ \expression
                          /                  \
                    const/\(null)      (null)/\(null)
                   /
                my/\(null)