anchor.diff:                 (length (cdr form))))
         (let* ((includee (lookup-included-filename (second form)))
                (*current-file* includee))
  +        (when (null includee)
  +          (error "Could not find included file '~S'" (second form)))
           (mappend #'process-toplevel-form (read-file includee))))))
   
   (defun mappend (func list)
  
positive.code: (defun lookup-included-filename (includee)
    ;; Later we could have some predefined include paths or something.
    ;; For now it's just relative to the including file
    (let* ((path (namestring
                   (merge-pathnames
                     includee (make-pathname
                                :directory (pathname-directory *current-file*)))))
           (extension (search ".nuc" path)))
      (if extension
        path
        (concatenate 'string path ".nuc"))))
  
  (defun compile-expr (expr)
    (etypecase expr
  
negative.code:   (llvm:with-objects ((*builder* llvm:builder)
                        (*module* llvm:module output-filename))
      (let ((*env* nil)
            (*current-file*
              (pathname (pathname
                          (if (char= (elt input-filename 0) #\/)
                            input-filename
                            (concatenate 'string
                                         (namestring *default-pathname-defaults*)
                                         input-filename)))))
            (*lambda-counter* 0))
        (compile-prelude)
        (dolist (form (mappend #'process-toplevel-form
  