From @smls

When calling `.skip` on a list which contains a `Slip` at the start, the
resulting `Seq` behaves in some cases as if *all* elements from that
`Slip` were skipped (instead of just the first one)​:

  say (<a b c>, <d e>).map(|*).skip.perl; # ("d", "e").Seq
  say (<a b c>, <d e>).map(|*).skip.eager.perl; # ("d", "e").Seq
  say (<a b c>, <d e>).map(|*).skip.eager.gist; # (d e)
  say (<a b c>, <d e>).map(|*).skip.eager.join; # de
  say (<a b c>, <d e>).map(|*).skip.cache.perl; # ("d", "e")
  say (<a b c>, <d e>).map(|*).skip.cache.join; # de
  say (<a b c>, <d e>).map(|*).skip.[*].gist; # (d e)

But it depends on how the returned `Seq` is iterated. In the following
cases it behaves correctly​:

  say (<a b c>, <d e>).map(|*).skip.gist; # (b c d e)
  say (<a b c>, <d e>).map(|*).skip.join; # bcde
  say (<a b c>, <d e>).map(|*).skip.cache.gist; # (b c d e)
  say (<a b c>, <d e>).map(|*).skip.[0..*].gist; # (b c d e)
  say (<a b c>, <d e>).map(|*).skip.iterator.pull-one; # b

It looks like¹ this bug has existed ever since the `.skip` method was
implemented² in January 2017.

[1] https://gist.github.com/Whateverable/973c1b6cb09af28a2249b4ba33165885
[2] rakudo/rakudo@8a6bfc6

This is Rakudo version 2017.08-156-ge6a695b27 built on MoarVM version
2017.08.1-171-gcf95892e
implementing Perl 6.c.

From @lizmat

On 17 Sep 2017, at 07​:29, Sam S. (via RT) <perl6-bugs-followup@​perl.org> wrote​:

# New Ticket Created by Sam S.
# Please include the string​: [perl #​132109]
# in the subject line of all future correspondence about this issue.
# <URL​: https://rt-archive.perl.org/perl6/Ticket/Display.html?id=132109 >

When calling `.skip` on a list which contains a `Slip` at the start, the
resulting `Seq` behaves in some cases as if *all* elements from that
`Slip` were skipped (instead of just the first one)​:

say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.perl;        \# \("d", "e"\)\.Seq
say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.eager\.perl;  \# \("d", "e"\)\.Seq
say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.eager\.gist;  \# \(d e\)
say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.eager\.join;  \# de
say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.cache\.perl;  \# \("d", "e"\)
say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.cache\.join;  \# de
say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.\[\*\]\.gist;    \# \(d e\)

But it depends on how the returned `Seq` is iterated. In the following
cases it behaves correctly​:

say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.gist;               \# \(b c d e\)
say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.join;               \# bcde
say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.cache\.gist;         \# \(b c d e\)
say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.\[0\.\.\*\]\.gist;        \# \(b c d e\)
say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.iterator\.pull\-one;  \# b

It looks like¹ this bug has existed ever since the `.skip` method was
implemented² in January 2017.

---
[1] https://gist.github.com/Whateverable/973c1b6cb09af28a2249b4ba33165885
[2] rakudo/rakudo@8a6bfc6

I think he problem here is in Seq.cache. Investigating...

The RT System itself - Status changed from 'new' to 'open'

From @zoffixznet

On Sat, 16 Sep 2017 22​:29​:57 -0700, smls75@​gmail.com wrote​:

When calling `.skip` on a list which contains a `Slip` at the start, the
resulting `Seq` behaves in some cases as if *all* elements from that
`Slip` were skipped (instead of just the first one)​:

 say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.perl;        \# \("d", "e"\)\.Seq
 say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.eager\.perl;  \# \("d", "e"\)\.Seq
 say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.eager\.gist;  \# \(d e\)
 say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.eager\.join;  \# de
 say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.cache\.perl;  \# \("d", "e"\)
 say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.cache\.join;  \# de
 say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.\[\*\]\.gist;    \# \(d e\)

But it depends on how the returned `Seq` is iterated. In the following
cases it behaves correctly​:

 say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.gist;               \# \(b c d e\)
 say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.join;               \# bcde
 say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.cache\.gist;         \# \(b c d e\)
 say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.\[0\.\.\*\]\.gist;        \# \(b c d e\)
 say \(\<a b c>, \<d e>\)\.map\(|\*\)\.skip\.iterator\.pull\-one;  \# b

It looks like¹ this bug has existed ever since the `.skip` method was
implemented² in January 2017.

---
[1] https://gist.github.com/Whateverable/973c1b6cb09af28a2249b4ba33165885
[2] rakudo/rakudo@8a6bfc6

---
This is Rakudo version 2017.08-156-ge6a695b27 built on MoarVM version
2017.08.1-171-gcf95892e
implementing Perl 6.c.

Thank you for the report. This is now fixed.

Fix​: rakudo/rakudo@41896b7bbf9fe5a
Test​: Raku/roast@2e23965fa1180b732

@zoffixznet - Status changed from 'open' to 'resolved'