Using interactive functions in functions

Using interactive functions in functions

[Bill Wohler]

  Consider the following fragment which runs tags-query-replace on a
  number of strings:

    (let ((strings '("foo" "bar")))
      (while strings
	(tags-query-replace (car strings) "newstring")
	(setq strings (cdr strings)))

  However, this loop ends when tags-query-replace returns the first time
  so "bar" is never replaced.

  What magic do I need to wrap tags-query-replace in to continue with
  the rest of the strings?

--
Bill Wohler <wohler@newt.com>  http://www.newt.com/wohler/  GnuPG ID:610BD9AD
Maintainer of comp.mail.mh FAQ and MH-E. Vote Libertarian!
If you're passed on the right, you're in the wrong lane.

Re: Using interactive functions in functions

[Michael Slass]

Bill Wohler <wohler@newt.com> writes:

>  Consider the following fragment which runs tags-query-replace on a
>  number of strings:
>
>    (let ((strings '("foo" "bar")))
>      (while strings
>	(tags-query-replace (car strings) "newstring")
>	(setq strings (cdr strings)))
>
>  However, this loop ends when tags-query-replace returns the first time
>  so "bar" is never replaced.
>

What happens if you use query-replace (which see) instead?
-- 
Mike Slass

Re: Using interactive functions in functions

[Stefan Monnier <foo@acm.com>]

>>>>> "Bill" == Bill Wohler <wohler@newt.com> writes:
>   Consider the following fragment which runs tags-query-replace on a
>   number of strings:
>     (let ((strings '("foo" "bar")))
>       (while strings
> 	(tags-query-replace (car strings) "newstring")
> 	(setq strings (cdr strings)))
>   However, this loop ends when tags-query-replace returns the first time
>   so "bar" is never replaced.
>   What magic do I need to wrap tags-query-replace in to continue with
>   the rest of the strings?

I'm not sure exactly how tags-query-replace terminates, but if
it ends up short-circuiting the loop above, then it's either through
`signal' or `throw'.  A quick investigation shows it's probably not
`throw', so try something like

         (condition-case err
             (tags-query-replace ...)
           (error
            (if (examine err if you feel like it)
                (do something)
              (do something else))))


-- Stefan