为什么Clojure的父亲说计划的真/假是破的？ [英] Why did father of Clojure say that Scheme's true/false are broken?

问题描述

Rich Hickey在本 Rich张贴：

Scheme #t几乎完全是
无意义，因为Scheme条件为
test for＃f / non-＃f，not＃f /＃ t。我不是
认为值#f有很多实用程序
无论什么，并且基于条件的
意味着写很多（if（not
（null？x）） ... where（如果x ...将在Clojure / CL中执行
，并且当
处理序列，过滤器等时，在表达力方面有大量的
减少。

邮件中的链接也是值得的，虽然第二个可能有点诗意。

In this video, Rich Hickey introduced Clojure for Lisp programmers.

At time 01:10:42, he talked about nil/false/end-of-sequence/'() among Clojure/Common Lisp/Scheme/Java. He said: "Scheme has true and false, but they are broken."

I don't understand why he said that and why does he consider it's "broken"?

解决方案

It strikes me you'd rather see it from the horse's mouth, so here's a choice extract from a message Rich posted:

Scheme #t is almost completely meaningless, as Scheme conditionals test for #f/non-#f, not #f/#t. I don't think the value #f has much utility whatsoever, and basing conditionals on it means writing a lot of (if (not (null? x))... where (if x... will do in Clojure/CL, and a substantial reduction in expressive power when dealing with sequences, filters etc.

The links in that message are also worthwhile, though the second one may be a bit poetic.

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