It is very interesting to compare Icon with Lisp. They have similar features, but a very different notation. One way to see this comparison is to write portions of Icon in Lisp. L end Sets and Tables Icon sets and tables are both based on a common set of dynamic hashing facilities. Sets are collections of values that support membership tests, insertion, deletion, union, intersection, and difference.
Tables are a more powerful type that associates a collection of keys with values.
They are more useful than sets, so we consider them in detail. You may also be interested in the Icon procedures that users have contributed to the Icon Program Library. It contains directories full of useful library procedures and programs. On-line reference documents for the IPL makes it easy to browse through.