Structural identification of dynamically generated, pattern-instantiation classes may be utilized using structural descriptions. Instead of describing classes only by name, and using that name to locate that class, a class may be referred to by a generator function and arguments to the generator function. A structural description may specify the generator function and the parameters. In addition, a structural description of a class may be used as a parameter to a generator function specified by another structural description. A structural description may be used similarly to a class name for virtually any situation in which a class name may be used. Classes may be compared using their structural descriptions. For example, two structural descriptions may be considered to be the same class if they specify the same generator function and parameters.