Megatest

;; extract index number given a header/data structure
(define (db:get-index-by-header header field)
  (list-index (lambda (x)(equal? x field)) header))

;; look up values in a header/data structure
(define (db:get-value-by-header row header field)
  (let ((len (if (vector? row)
  (let ((len (vector-length row)))
		 (vector-length row)
		 0)))
    (if (or (null? header) (not row))
	#f
	(let loop ((hed (car header))
		   (tal (cdr header))
		   (n   0))
	  (if (equal? hed field)
	      (handle-exceptions
	       exn
	       (begin
		 (debug:print 0 *default-log-port* "WARNING: attempt to read non-existant field, row="
		 (debug:print 4 *default-log-port* "WARNING: attempt to read non-existant field, row="
			      row " header=" header " field=" field ", exn=" exn)
		 #f)
	       (if (>= n len)
		   #f
		   (vector-ref row n)))
	      (if (null? tal) #f (loop (car tal)(cdr tal)(+ n 1))))))))