(define (linearize-attributes attr-list)
  (string-append  
    (linearize-attributes-1
      (reverse attr-list) "" (length attr-list))))

(define (linearize-attributes-1 attr-list res-string lgt)
  (cond ((null? attr-list) res-string)
        ((>= lgt 2) 
          (linearize-attributes-1 
           (cddr attr-list)
           (string-append 
            (linearize-attribute-pair
             (car attr-list) (cadr attr-list)) " " res-string)
           (- lgt 2)))
        ((< lgt 2) 
          (error "The attribute list must have even length"))))

(define (linearize-attribute-pair val attr)
  (string-append (as-string attr)
                  " = " (string-it (as-string val))))