undefined | Better HN

0 pointswccrawford14y ago0 comments

I can read just enough of that that it confuses me why it doesn't work. Care to explain?

0 comments

3 comments · 1 top-level

glogla14y ago· 2 in thread

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.

eadvgf14y ago

If we are talking Common Lisp, the default test is actually EQL. ((eq 1 1) is not necessarily T).

Ah, I see. Thanks.

j / k navigate · click thread line to collapse