Magic Tree

“Leaves turned to soil beneath my feet. Thus it is, trees eat themselves.”

-- David Mitchell, Cloud Atlas

Magic Tree parses Clojure code into an AST suitable for powering smart, structural editing environments. Like rewrite-cljs, it preserves whitespace and uses zippers as an intermediate data structure. The current form of Magic Tree is just a first step to a bigger vision.

What can it do?

1. Parse raw Clojure source into an AST (magic-tree.core/ast) and corresponding zipper (magic-tree.core/ast-zip).
2. Traverse and edit as desired.
3. Emit Clojure (magic-tree.core/string or magic-tree.core/sexp) with existing whitespace intact.

An example of real-world usage can be found in Maria, a beginner-friendly ClojureScript REPL.

Testing

lein doo phantom test

Future

In addition to being 'whitespace-aware', a magic-tree AST should also be 'cursor-aware' and 'selection-aware', and thus encapsulate nearly the full state of an editor. This will simplify the implementation of new editing commands, make testing easier, and allow for more freedoms in the visual representation and manipulation of code. (CodeMirror will be just one of many possible 'views' on an AST, one which happens to use a string representation.)