Question

I am new to vimscript so this is probably and easy one. I know of the update command which is like write except it only writes if there have been changes made. I would like to have something like

if ( update )
    call expensiveOperation()

where the expensive operation is only called if update actually did something. But, I’m not familiar enough with vim to know how to do this. How can this be achieved?

Answer 1

Not directly, it is possible: update does some operation if &modified option appears to be true (this option’s value is ignored when &buftype is either “nofile” or “nowrite”). Hence you should do the following:

let wasmodified=(&modified && !(&buftype is# 'nowrite' || &buftype is# 'nofile'))
update
if wasmodified
    call ExpensiveOperation()
endif