On 11/12/13 10:31 AM, tn wrote:
On Tuesday, 12 November 2013 at 15:56:25 UTC, Andrei Alexandrescu wrote:
On 11/12/13 12:54 AM, tn wrote:
...
An alternative would be to check for nans explicitly.
I think NaNs are singular unordered values that make invalid inputs
for either sort or isSorted. We should simply add an assert to isSorted.
But sort and isSorted both allow user to provide a custom "less"
function. What if the user needs NaNs and, for example, wants to sort
them before all the other values? Then he calls "arr.sort!((a,b) => a <
b || (isnan(a) && !isnan(b)))" and the code asserts?
I think this is a misunderstanding. I never advocated inserting
specialized asserts for floating-point numbers. http://goo.gl/3dGGkf
takes care of that the right way - by making sure that the less
predicate is sensible for the kind of work isSorted and sort do. That is
regardless of the nature of the objects being sorted.
Andrei
