Continue last M-x tags-search or M-x tags-query-replace command.
Used noninteractively with non-nil argument to begin such a command (the
argument is passed to `next-file', which see).
Two variables control the processing we do on each file: the value of
`tags-loop-scan' is a form to be executed on each file to see if it is
interesting (it returns non-nil if so) and `tags-loop-operate' is a form to
evaluate to operate on an interesting file. If the latter evaluates to
nil, we exit; otherwise we scan the next file.
(fn &optional FIRST-TIME)