command mode ranges based on patterns

In command mode you can specify a range of lines to operate on, based on patterns, rather than absolute (or relative line numbers). This can be a great way to isolate changes without looking up the individual line numbers.

:/start/,/end/cmd<CR>

On a Python file, this might look like:

def main():
    foo = do_something()
    bar = do_something_else(foo)
    return bar

:/def main/,/return/s/foo/baz/g<CR>

results in:

def main():
    baz = do_something()
    bar = do_something_else(baz)
    return bar