Hacker News Reader

Idempotency: the ability to be able to hit Ctrl+C several times in a row, just to be sure.

Oddly, C-g in Emacs isn't idempotent when it's hung or doing something slow.

https://www.gnu.org/software/emacs/manual/html_node/emacs/Em...

A more subtle case is that C-d (EOF for anyone except DOS) is widely not idempotent. Depending on the exact programs involved, it changes after pressing it about 10 times.

Reply on news.ycombinator.com