[CM] [CLM] eval within the run-body.

[Bill Schottstaedt]

examp.scm has a similar instrument named chain-dsps (for Snd/CLM, not CL/CLM),
but in this case it might be simpler to use a loop and a case statement:

   (let ((current-output 0.0))
     (do ((i 0 (1+ i)))
         ((= i num-gens))
       (case (aref gens i)
         (0 (setf current-output (fir-filter fir current-output)))
         (1 (setf current-output (delay dly current-output)))
         (2 (setf current-output (formant frm current-output)))
	...
	))
      (locsig locs samp current-output))

where we obviously set up the various generators in advance.  (There's an
example in the test file ug.ins: "s4").