史蒂夫·洛什 posted the following Clojure snippet :
; Integers and Longs are equal.
(= (Integer. 1) (Long. 1))
true
; Even negative ones.
(= (Integer. -1) (Long. -1))
true
; When you use them as keys in maps, the maps are still equal.
(= {(Integer. 1) :foo} {(Long. 1) :foo})
true
(= {(Integer. -1) :foo} {(Long. -1) :foo})
true
; When you use positive numbers as keys to sets, they're also equal.
(= #{(Integer. 1)} #{(Long. 1)})
true
; But negative ones aren't. But only in sets. Maps are fine. lol.
(= #{(Integer. -1)} #{(Long. -1)})
false
这种行为的原因是什么?它是否被认为是一个缺陷,或者是否存在“形式逻辑”/集合论为什么 (Integer.-1)
不等于 (Long.-1)
在持久集中?
最佳答案
这是 Clojure 中的一个错误:http://dev.clojure.org/jira/browse/CLJ-1106
这里是满足堆栈溢出的愚蠢字符限制的文本
关于clojure - Clojure 中映射和集合之间的行为不一致,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/13312580/