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Comment by kot-behemoth | Hacker News Reader

There is an app called Lisping which allows writing a variety of Lisps (Scheme and Clojure) on iPads. The great thing about it was that there was minimal typing - the interface made the AST very clickable, with minimal cursor movement. When I tried it, it was such a great way to edit code on an iPad. Demo video: https://www.youtube.com/watch?v=nHh00VPT7L4

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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?

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.

Wow, I watched the whole video and all I can say is -- huh?

That looked totally painful, and not at all fun. Granted, much of this is due to the fact that it's a touch interface, but I'm not seeing it as very useful.

I'm a huge Lisp/Scheme/Clojure fan, but I didn't find this at all impressive.

I think that the keyboard should always stay present and there should be no dialog appearing when he edits the symbols. There should only be a textinput at the location of the symbol. Also, some icons on the right could be present so that you could do some more actions.

Yeah, it's really hard to see the utility in that.

That literally takes 10x longer to enter anything than it does in a decent editor. I imagine some vim and emacs wizards can edit even faster than that.

Dumb snark incoming but it's like using a hammer to chop wood.

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