Attached is my use case which is parsing of PDF cross reference indices. There are normally three numeric entries per line. e.g.
xref 0 8 0000000000 65535 f 0000000009 00000 n 0000000074 00000 n 0000000120 00000 n Which populates nicely into an array of 'n' lines of shape 3. There's the rare, but possible case of an xref section with zero entries xref 0 0 (I've encountered real-world PDF's like this). The attached grammar/actions attempted to handle it as an array of shape [0;3], but wont work on current Rakudo. Just my preferred solution for the above case. - David On Sun, Aug 27, 2017 at 12:38 PM, Brandon Allbery via RT < perl6-bugs-follo...@perl.org> wrote: > > Well, what do you mean? Of course you can't put anything into it, and any > > attempt to index it will throw. It may seem useless, however, if you can > > have > > an empty array, why can't you have a shaped empty array? > > > > Only if all dimensions are unindexable. Otherwise you have something with > inaccessible slots (and, potentially thereby, not truly leaked but > unusable, memory). > > And an empty unshaped array, in addition to being usable as such > (degenerate case of all shaped dimensions being size 0), can be made > non-empty. Shaped arrays cannot. > >
Xref.pm
Description: Perl program