Chapter 9



This chapter describes techniques for sealing portions of a Dylan program by declaring that classes or functions will never be used in particular ways, or will never be extended in particular ways. These sealing directives enable a range of compiler optimizations, and also clarify the programmer's intent.

The sealing directives include:

With the exception of define sealed domain, these directives are expressed as adjectives on the generic function definition, class definition, method definition, or slot specification.