# New Ticket Created by "brian d foy"
# Please include the string: [perl #132543]
# in the subject line of all future correspondence about this issue.
# <URL: https://rt.perl.org/Ticket/Display.html?id=132543 >
I first asked about this on Stackoverflow:
https://stackoverflow.com/q/47704428/2766176
A .tail on a .tail appears to do the wrong thing:
> my $list = <a b c d e f g h i j>;
(a b c d e f g h i j)
> $list.tail(5).tail
Nil
But throwing a list in there works:
> $list.tail(5).list.tail
j
Timo said:
.tail and .tail(1) are implemented with
Rakudo::Iterator.LastValue and
Rakudo::Iterator.LastNValues respectively, which differ
quite a bit in implementation.
https://github.com/rakudo/rakudo/blob/master/src/core/Rakudo/Iterator.pm#L1807
And he figures:
tail on the List takes an iterator and skips it ahead $n
items. then, the tail method on Seq calls count-only on
it to figure out how far to skip ahead to get the last
$m items. However, count-only on the first iterator just
gives you the total number of items in the original
list. It should probably either signal an error when
asked for count-only, or it should calculate the proper
amount of items left.
