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A comment on Interviews Can Be a Terrible Way to Identify Good Programmers. Parent comment

Re:Interviews Can Be a Terrible Way to Identify Good Program... by glogla on Sunday May 06, 2012 @03:37AM (#3934444)
Oh boy.

I seem to remember the

  (member 1 '(1 2 3)) -> t
  (equal '(1 2) '(1 2)) -> t
  (member '(1 2) '('(1 2) '(3 4))) -> nil
bug. It took me just three hours, but boy was it annoying. In the end, it was just me not knowing the language of course.
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Re:Interviews Can Be a Terrible Way to Identify Good Program... by wccrawford on Sunday May 06, 2012 @06:44AM (#3934766)
I can read just enough of that that it confuses me why it doesn't work. Care to explain?
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Re:Interviews Can Be a Terrible Way to Identify Good Program... by glogla on Sunday May 06, 2012 @07:11AM (#3934809)
The problem is, that

  (equal 1 1) -> t
  (equal '(1 2) '(1 2)) -> t

  (eq 1 1) -> t
  (eq '(1 2) '(1 2)) -> nil
because eq tests for the same symbol, while equal test for the same list. Member uses eq, not equal.
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Re:Interviews Can Be a Terrible Way to Identify Good Program... by eadvgf on Sunday May 06, 2012 @04:19PM (#3936186)
If we are talking Common Lisp, the default test is actually EQL. ((eq 1 1) is not necessarily T).
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Re:Interviews Can Be a Terrible Way to Identify Good Program... by wccrawford on Sunday May 06, 2012 @08:54AM (#3934993)
Ah, I see. Thanks.
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