On Sat, Sep 19, 2009 at 9:45 PM, David Green <david.gr...@telus.net> wrote:
> On 2009-Sep-19, at 5:53 am, Solomon Foster wrote:
>
> The one thing that worries me about this is how :by fits into it all.
>> rakudo: given 1.5 { when 1..2 { say 'between one and two' }; say
>> 'not'; };
>> rakudo: given 1.5 { when Range.new(from => 1, to => 2, by => 1/3) {
>> makes me very leery. I know :by isn't actually implemented yet, but what
>> should it do here when it is?
>>
>
> Exactly: 1.5 is "between" 1 and 2, but if you're counting by thirds, 1.5 is
> not in the list(1..2 :by(1/3)). Sure, we can stipulate that this is simply
> how the rules work, but people are still going to get confused. On the
> other hand, we can get rid of the list/series/:by part of Ranges without
> losing any power (move that capability to ... instead), and cut down on the
> confusion.
1..2 is used abstractly to indicate a range, even though it's actually an
iterator that will return two values. However, once you apply an explicit
:by, I think you've gone past that abstraction, and it's no longer
reasonable to expect that values that fall between your iterations will
match.
