Created
December 5, 2016 12:04
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common lisp 的 NIL
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描述 | |
在 common lisp 中经常可以看到NIL, NIL 有两个含义 | |
1. boolean 中的 false | |
2. 空列表 | |
第一种含义在其他语言中(比如 python 是比较符合行为习惯的), 但第二种就少见, | |
在其他语言中, 一般如果为空列表, 对空列表求值可能为 nil, 而不是 nil 表示空列表 |
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