The checker utilities are provided to make writing checker functions. They are provided in a few layers, each layer provides new functionality in addition to the lower one. These modules are (in order):
racket/sandbox: is the basic sandbox evaluation code, which is the basic functionality checkers build on.
handin-server/sandbox: contains a wrapper that configures the Racket sandbox for the handin server.
handin-server/utils: contains additional utilities for dealing with handin submissions, as well as a few helpers for testing code.
handin-server/checker: automates the task of creating a checker function (in "<active-assignment>/checker.rkt" modules) to cope with common submission situations.
The following sections describe each of these modules.