Bracket Parse
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This is intended to convert a bracketd lisp/prolog like string into a tree where each bracket is considered a parent of some kind
Changes v0.1.2
Added tail_n for tail chain skipping as tail().tail() drops the borrow.
Added tail_h for tail(n).head(), again to avoid borrow drops().
Impl Display for Bracket //TODO Escape strings safely
Coming in v01.3
Iterator on &Bracket