[dexen]

I particularly like how in Acme, when selection is zero-width ("empty"), it is the cursor. Conversely selection can be extended from cursor in any direction.

As a side effect, this greatly simplifies the API for manipulating both.

[gcassie]

I actually used this pattern as well and I really like it. I store another property called `mark_idx`. When `cursor_idx` and `mark_idx` are the same then it's just a cursor. When they differ, the range between them is the selection.

[danhau]

What is Acme in this context? Id like to get an idea of what you mean.

[tomjakubowski]

the acme text editor, originally from plan9

http://acme.cat-v.org/ https://www.youtube.com/watch?v=dP1xVpMPn8M

[RACEWAR]

https://plan9.io/sys/doc/acme/acme.html