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19 lines
655 B
19 lines
655 B
2 years ago
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Exercise 3.63: Louis Reasoner asks why the
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sqrt-stream procedure was not written in the following more
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straightforward way, without the local variable guesses:
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(define (sqrt-stream x)
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(cons-stream
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1.0
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(stream-map (lambda (guess)
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(sqrt-improve guess x))
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(sqrt-stream x))))
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Alyssa P. Hacker replies that this version of the procedure is considerably
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less efficient because it performs redundant computation. Explain Alyssa’s
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answer. Would the two versions still differ in efficiency if our
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implementation of delay used only (lambda () ⟨exp⟩) without
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using the optimization provided by memo-proc (3.5.1)?
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