((string? val)  (string->number val))
   ((symbol? val)  (string->number (symbol->string val)))
   (else     #f)))

;; NB// this is *illegal* pgint
(define (s:illegal-pgint val)
  (cond
   ((> val 2147483647) 1)
   ((< val -2147483648) -1)
   (else #f)))

(define (s:any->pgint val)
  (let ((n (s:any->number val)))
    (if n
	(if (s:illegal-pgint n)
	    #f
	    n)
	n)))

;; string is a string and non-zero length
(define (misc:non-zero-string str)
  (if (and (string? str)
           (> (string-length str) 0))
      str
      #f))