Lazy commands

[hadronized]

@topisani made an interesting commit recently allowing not to run a shell command if the buffer hasn’t changed. It uses a trick to find a function ending with -0, and we pass a timestamp as in place of the 0 so that it can use timestamps to know whether buffers have changed without any condition.

We should visit that idea to optimize.

[krobelus]

Neat, I want this too, don't want to fall behind on street cred ;)

[hadronized]

It looks interesting, but clearly it’s optimizing.