[CM] run (guile) type declarations

[Bill Schottstaedt]

Here's one way:

(definstrument (add beg dur freq amp) 
 (let* ((start (seconds->samples beg)) 
        (end (+ start (seconds->samples dur))) 
        (vec (make-vector 20))
        (env 0))
   (do ((i 0 (1+ i))) ((= i 20)) 
     (vector-set! vec i (make-oscil (* (1+ i) 100)))) 
   (run 
    (lambda () 
      (declare env float) 
      (do ((i start (1+ i))) 
          ((= i end)) 
        (let ((sum 0.0)) 
          (do ((j 0 (1+ j)))
              ((= j 20)) 
            (set! sum (+ sum (* (sin env) (oscil (vector-ref vec j)))))
            (set! env (+ env (/ pi 20.))))
          (outa i (* amp .05 sum) *output*)))))))

but it seems perverse -- I'll look into making the optimizer's type checker smarter
about this sort of case.