In vim, how do I define a function that can be called without :call?

Question

How do I define a function so that I can call it from command-line mode without :call in front of it?

Right now, I have to do this: :call TrimWhitespace()

I want to define it so that I can do this: :TrimWhitespace

Answer 1

This won't be a function, you should create a command instead. Check the documentation for commands (:help user-commands in Vim).

The simplest case is of a command to call a function:

command! TrimWhitespace call TrimWhitespace()