I haven't finished SICP so I'm not sure which bit you're talking about, could you please point it out? http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-4.h

I haven't finished SICP so I'm not sure which bit you're talking about, could you please point it out? http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-4.html#%_toc_start http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-4.html#... All IO is inherently impure, right? At best you're going to be composing funtions out of smaller functions that implement your graphics desires. How can you get around having e.g. a circle(radius, x-pos, y-pos, line-color, fill-color) function that draws per your specifications? There's no reason you couldn't implement that circle function using turtle...