[racket] Typo in signatures

From: John Riedl (riedl at umn.edu)
Date: Tue Oct 4 17:15:49 EDT 2011

Of course something like check-within is what is needed.  The point
is: there ought to be something like check-within that can be used in
a function to test "equality within a delta".

I suppose it's fine for each student to define one herself; I'm just
saying I think it's so important it ought to be built-in.


On Tue, Oct 04, 2011 at 02:23:16PM -0400, Shriram Krishnamurthi wrote:
> check-within
> http://docs.racket-lang.org/test-engine/index.html#(def._((lib._test-engine/racket-tests..rkt)._check-within))

Yes.  That's exactly what students should be using ubstead of anything
that even looks like an equality-test.  The only time you'd want an
actual equality test on inexact numbers is whan you're using it
algorithmically instead of numerically, such as attaching a memo-pad to
a function on inexactt numbers.

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