anchor.diff:  (defun accumulated-toplevel? (section)
     (not (eq 'accumulated-toplevel section)))
   
  -(defun map-transpiler-sections (fun sections cached-sections)
  -  (with-queue results
  -	(dolist (i sections (queue-list results))
  -      (with-cons section data i
  -        (with-temporaries ((transpiler-current-section *transpiler*)       section
  -                           (transpiler-current-section-data *transpiler*)  data)
  -          (enqueue results (. section (? (compile-section? section cached-sections)
  -                                         (funcall fun section data)
  -                                         (assoc-value section cached-sections)))))))))
  +(defun map-section (x fun sections cached-sections)
  +  (with-cons section data x
  +    (with-temporaries ((transpiler-current-section *transpiler*)       section
  +                       (transpiler-current-section-data *transpiler*)  data)
  +      (. section (? (compile-section? section cached-sections)
  +                    (funcall fun section data)
  +                    (assoc-value section cached-sections))))))
  +
  +(defun map-sections (fun sections cached-sections)
  +  (filter [map-section _ fun sections cached-sections]
  +          sections))
   
   (defun development-message (fmt &rest args)
     (when *development?*
  
positive.code:     (backend (middleend data))))
  
  (defun generic-compile-2 (sections)
    (alet (map-transpiler-sections #'codegen-section
                                   sections
                                   (transpiler-compiled-files *transpiler*))
      (= (transpiler-compiled-files *transpiler*) !)
      (cdrlist !)))
  
  
negative.code:     (error "Don't know what to do with section ~A." section)))
  
  (defun generic-compile-1 (sections)
    (alet (map-sections #'frontend-section
                        sections
                        (transpiler-frontend-files *transpiler*))
      (= (transpiler-frontend-files *transpiler*) !)))
  
  (defun make-toplevel-function ()
  