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>the interface made the AST very clickable, with minimal cursor movement.

Every so often the concept of visual programming comes up, where people wish that instead of editing text they could somehow directly manipulate an AST. Wouldn't it be funny if it turned out that it was Lisp they were looking for all along?

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Lisp is certainly amenable to this, and structured editors for lisp have been around for a long time, but the concept is not specific to lisp except inasmuch as it's much easier to implement since the syntax is so similar to the AST.

For instance, I like to use Paredit [1] for elisp and Racket hacking, and there's a similar mode for Haskell in emacs [2].

[1] https://www.emacswiki.org/emacs/ParEdit [2] https://github.com/chrisdone/structured-haskell-mode

"...much easier to implement since the syntax is so similar to the AST."

Hmmm. Updating my grammars to ANTLR 4.x's LL(Star) has been very rewarding. The resulting parse tree and AST are the same, if done carefully.

I've never been smart enough to create a structured, incremental editor. Eg two-way editing. Your comment nudges me to pondering trying again.

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