A lot of people here have pointed out that closures are not the same as function pointers in C, and for that I thank them. I have added that note to the blog po

A lot of people here have pointed out that closures are not the same as function pointers in C, and for that I thank them. I have added that note to the blog post (it should be up on GitHub shortly), but I would also like to say that the reason for introducing function pointers in that way was to establish a sense of familiarity for those coming from Ruby / Python / JavaScript, who are not well-acquainted with their use in C.