#lang scheme/base (require 2htdp/universe ; "sb-universe.ss" htdp/error ; check-arg "tiles.ss" "io-stuff.ss") (provide ; (all-from-out "sb-universe.ss") (all-from-out "tiles.ss") ; includes all-from-out 2htdp/image, plus a few simple add-ons (all-from-out "io-stuff.ss")) ; includes with-{input-from,output-to}-{string,file}, with-io-strings (provide show-it) (provide (all-from-out 2htdp/universe)) (define (show-it img) (check-arg 'show-it (image? img) "image" "first" img) img)