[geocar]

> A real life editor would for example have to the concept of active parts of files to edit files larger than fits in memory

Why? Address space is cheap, and a is simply map'd to the file.

I don't have any text files bigger than 64 bits of address space. Do you?

> the ability parse different encodings and line endings

vi doesn't do this. acme doesn't do this. I would agree it's a popular feature, but I still think it's a mistake: If every program on my computer has to continuously parse and deparse bytes into text, and be aware of all the different things every other operating system calls text, then it seems like a waste; it seems redundant. It's a waste of code, and of memory, and I think any mere editor that "needs" this lacks sufficient composition.