Exercise 3.24: In the table implementations
above, the keys are tested for equality using equal? (called by
assoc). This is not always the appropriate test. For instance, we
might have a table with numeric keys in which we don’t need an exact match to
the number we’re looking up, but only a number within some tolerance of it.
Design a table constructor make-table that takes as an argument a
same-key? procedure that will be used to test “equality” of keys.
Make-table should return a dispatch procedure that can be used to
access appropriate lookup and insert! procedures for a local
table.
练习 3.24：在上面的表实现中，键的相等性检测使用 equal?（由 assoc 调用）。但这并不总是合适的检测方式。例如，我们可能有一个以数值为键的表，查找时不需要精确匹配，只需在某个容差范围内即可。请设计一个表构造函数 make-table，它接受一个 same-key? 过程作为参数，该过程将用于检测键的“相等性”。make-table 应返回一个分派过程，可用于访问适用于本地表的 lookup 和 insert! 过程。