make-thread with lambda form instead of function symbol

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Okay, one more thread question...

I'm trying to do something that seems like it would be a normal use
case: spawn a series of threads which call the same function using
different external processes. Practically what this means is that I want
to pass a function-plus-argument form to make-thread, not a function
symbol. Something like:

(let* ((results)
       (sources '(source1 source2))
       (threads
	(mapcar
	 (lambda (s)
	   (make-thread
	    (funcall
	     (lambda ()
	       (push (get-stuff-from-source s) results)))))
	 sources)))
  (mapc #'thread-join threads)
  results)

The (funcall (lambda () thing was the only way I could get anything but
nil out of the thread functions. I think I'm fooling myself, though: so
far as I can tell, `get-stuff-from-source' is fully evaluated before the
thread is made, and nothing at all happens during the #'thread-join
loop.

Is it possible to give make-thread anything but a function symbol? The
only other thing I could think of was looping over the sources and
making ad-hoc symbols:

(fset (make-symbol (format "%s-dummy-function" (source-name source)))
      (lambda () (push (get-stuff-from-source source) results)))

That seems ugly, but perhaps not that bad.

Thanks in advance,
Eric