On Wed, Aug 19, 2009 at 1:54 PM, Moritz Lenz via RT <
perl6-bugs-follo...@perl.org> wrote:
>
> Since the discussion came up on #perl6 if this is really the expected
> behaviour, S09 says:
>
> As the end-point of a range, a lone "whatever" means "to the maximum
> specified index" (if fixed indices were defined):
>
> say @calendar[5..*]; # Same as: say @calendar[5..11]
> say @calendar{Jun..*}; # Same as: say @calendar{Jun..Dec}
>
> or "to the largest allocated index" (if there are no fixed indices):
>
> say @data[1..*]; # Same as: say @results[1..5]
>
>
> It doesn't mention how the postcifcumfix:<[ ]> is supposed to introspect
> those to find out if the WhateverCode object constructed by 1..* needs
> to receive self.elems or self.elems-1 as an argument.
>
> Which is why I CC: p6l to get some ideas or clarification, and if we
> want to maintain this DWIMmy but not very consistent behaviour.
>
I like it the way S09 says it.
But there is a problem with sparse arrays, isn't there?
S32/Containers (S32-array) says this about elems:
> our Int method elems (@array: ) is export
>
> Returns the length of the array counted in elements. (Sparse array types
> should return the actual number of elements, not the distance between the
> maximum and minimum elements.)
>
For arrays, it appears that using end is more relevant:
>
> our Any method end (@array: ) is export
>
> Returns the final subscript of the first dimension; for a one-dimensional
> array this simply the index of the final element. For fixed dimensions this
> is the declared maximum subscript. For non-fixed dimensions (undeclared or
> explicitly declared with *), the index of the actual last element is used.
>
Does that seem usable to y'all?
--
Jan
