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On 19 Aug 2004, at 18:04, Luke Palmer wrote:
The one in Perl 5 that stands out most was the cause for the only patch I ever sent to p5p: the rand function. "rand $x" will give you a uniformly distributed random number in [0, $x) for any $x EXCEPT 0. If you say "rand 0", it gives you a random number between 0 and 1, which was supposed to be What I Meant. That led to code like this (Perl6ized as usual):
my $num = $param == 0 ?? 0 : rand $param;
my $num = $param == 0 ?? 0 :: rand $param;
surely?
Repeating the test that it did itself, just to get consistent behavior. We must be careful not to repeat mistakes like this in the design of Perl 6 [1].
It would be nice if rand behaved a bit more sanely in Perl 6. I can understand the reasoning for making rand 0 produce between 0 and 1, but that doesn't mean I have to like it. If that behaviour is required, then rand undef; would behave as expected (call with no parameters to get [0, 1), with one param to get [0, $param) ), but really if you want a random number between 0 and 1 why aren't you calling rand 1?
Feels like a Cism. Ick. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (Darwin)
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