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26 lines
880 B
26 lines
880 B
2 years ago
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Exercise 1.32:
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Show that sum and product (Exercise 1.31) are both special
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cases of a still more general notion called accumulate that combines a
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collection of terms, using some general accumulation function:
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(accumulate
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combiner null-value term a next b)
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Accumulate takes as arguments the same term and range specifications as
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sum and product, together with a combiner procedure (of
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two arguments) that specifies how the current term is to be combined with the
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accumulation of the preceding terms and a null-value that specifies what
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base value to use when the terms run out. Write accumulate and show how
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sum and product can both be defined as simple calls to
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accumulate.
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If your accumulate procedure generates a recursive process, write one
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that generates an iterative process. If it generates an iterative process,
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write one that generates a recursive process.
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