[fivhjvf]

Tragically, this blog post is not using the words "continuation passing style" to refer to CPS. If you read it you will see that the author is talking about a "style" of code which involves passing multiple lambdas to a function.

Why he thinks it is a good idea to refer to this idiom as "continuation passing style" is anybody's guess. It is not CPS. His usage is confusing and to me it seems most likely that he just wants to be seen using a fancy ten-dollar technical term with the ring of prestige. Basically, the kind of blog post that wastes the time of unsuspecting readers.

[tonyg]

You are mistaken. This is exactly continuation passing style. The two arguments `if-found` and `if-not-found` are continuations of `lookup`. Note that their invocations are in tail position within lookup.