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27 lines
804 B
27 lines
804 B
2 years ago
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Exercise 1.5: Ben Bitdiddle has invented a test
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to determine whether the interpreter he is faced with is using
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applicative-order evaluation or normal-order evaluation. He defines the
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following two procedures:
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(define (p) (p))
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(define (test x y)
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(if (= x 0)
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0
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y))
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Then he evaluates the expression
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(test 0 (p))
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What behavior will Ben observe with an interpreter that uses applicative-order
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evaluation? What behavior will he observe with an interpreter that uses
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normal-order evaluation? Explain your answer. (Assume that the evaluation
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rule for the special form if is the same whether the interpreter is
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using normal or applicative order: The predicate expression is evaluated first,
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and the result determines whether to evaluate the consequent or the alternative
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expression.)
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