Through the use of interpreters it is possible to teach programming languages in an analytic way without the mathematical overhead associated with other formal methods. This is a natural evolution of programming language pedagogy from present approaches that are largely descriptive. As a bonus, students receive training in the use of meta-linguistic abstraction in program design. An example of this approach is presented along with suggested variations and discussion of a number of practical considerations that may be crucial to success in the classroom.

Traditional compilation courses use formal methods for parsing, but treat the more important semantic aspects informally. We present a one semester course in which compiler development is reduced to a number of transformation steps, each of which is formally specified, easily tested, and clearly motivated by semantic considerations. The source language is substantial (essentially the host language of the compiler) and the target is a popular RISC architecture.

Continuations, when available as first-class objects, provide a general control abstraction in programming languages. They liberate the programmer from specific control structures, increasing programming language extensibility. Such continuations may be extended by embedding them in procedural objects. This technique is first used to restore a fluid environment when a continuation object is invoked. We then consider techniques for constraining the power of continuations in the interest of security and efficiency. Domain mechanisms, which create dynamic barriers for enclosing control, are implemented using fluids. Domains are then used to implement an unwind-protect facility in the presence of first-class continuations. Finally, we present two mechanisms, wind-unwind and dynamic-wind, that generalize unwind-protect.

Continuations, when available as first-class objects, provide a general control abstraction in programming languages. They liberate the programmer from specific control structures, increasing programming language extensibility. Such continuations may be extended by embedding them in functional objects. This technique is first used to restore a fluid environment when a continuation object is invoked. We then consider techniques for constraining the power of continuations in the interest of security and efficiency. Domain mechanisms, which create dynamic barriers for enclosing control, are implemented using fluids. Domains are then used to implement an unwind-protect facility in the presence of first-class continuations. Finally, we demonstrate two mechanisms, wind-unwind and dynamic-wind, that generalize unwind-protect.