CIS 352   —   SPRING 2009

Quiz 3a: Scope and Practice

Version 1 — 7 April 2009

When, Where, and How

• When: Thursday, April 16
• Where: in class
• How: Closed book, closed notes.

Coverage

• You should be familiar with all the topics from Exam 1 and Exam 2.

• Terms.

  Know the following terms, all of which are in the index of the text or in notes I've provided. Be able to define them and apply them (or give an example). For example, be able to define what a bound variable is and to pick out the bound variables in some Scheme code. in red and underlined below.

  1. bound variable
  2. call-by-name parameter passing
  3. call-by-need parameter passing
  4. call-by-reference parameter passing
  5. call-by-value parameter passing
  6. call-by-value-result
  7. capture of a variable
  8. concrete syntax
  9. control context
  10. continuation
  11. contours
  12. denoted value
  13. dynamic scoping
  14. expressed value
  15. free variable
  16. lazy evaluation
  17. lexical scoping
  18. nested region
  19. shadowed variables
  20. thunk
  21. variable aliasing
  22. variable assignment

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• Be prepared for the following sorts of questions.

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  • What does the following code return when

    1. call-by-value parameter passing is used?
    2. call-by-reference parameter passing is used?
    3. call-by-name parameter passing is used?
    4. call-by-need parameter passing is used?
    5. call-by-value-result parameter passing is used?
    Explain your answers.

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  • What does the following code return when

    1. lexical scoping is used in the language?
    2. dynamic scoping is used in the language?
    Explain your answers.

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  • Here's an expression in our defined language involving the try-handle construct: what is the value of the expression?

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  • Write a Scheme procedure to do X
    (where X is something not too involved).

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Practice

• Some questions from last year's Exam 3 (solutions later)