(module context mzscheme 
  (provide build-expand-context
	   generate-expand-context)

  (define (build-expand-context v)
    (let ([c (syntax-local-context)])
      (if (pair? c)
	  (cons-immutable v c)
	  (list-immutable v))))

  (define (generate-expand-context)
    (build-expand-context (gensym 'internal-define))))