Comment by gumby

>Text isn't the optimal format because a program is not a lineal thing, but closer to a tree structure.

I can tell you what it's like from experience. The Interlisp D environment used a structure editor rather than a text editor. I found it infuriating and clumsy. Admittedly I had come from the emacs-infused PDP-10/Maclisp & Lispm world, so I gave it several months, but in the end I adapted an Emacs someone else had started and did all my editing in that.

I figure if this would work for any language it would be Lisp, and it didn't work for me. It sounds like a great idea, since if the editor's "buffer structure" is the program structure it's easy to write lambda functions to, say, support refactoring your code. But it was rarely convenient.

The other thing that didn't work for me was that it was of course a mouse-driven interface (this was PARC after all) and I found shifting my hand off the keyboard all the time slowed me down a lot too.