Heres my go. Im not sure i want to think about golfing while it needs to handle error cases. If we can assume that all inputs are valid (and a better input format) then golfing it might be interesting.

Update: I didnt test my original solution properly. Its actually broken. Ive stuck it in a comment if you want to see my foolishness and i've posted a new version.

The updated code. Ive posted it three times, pre-golf, golf with error handling, and golf without error handling. golf with error handling (including error message) is 180 chars, golf without error handling is 126. Ive not counted the sub declaration itself. (ie the sub NAME { } is excluded for the count)

use strict;
use warnings;
use Data::Dumper;
use Carp;

sub subrange_pre_golf {
  my ($r1,$r2,$ary,$s,$f)=@_;
  ($s,$f)=(0,$#$ary) unless $s && $f;
  ($_<$s && $_<$f or $_>$s && $_>$f) and die "Bad range!"
    for $r1,$r2;
  my ($dx,$idx,@ret)=($r2 <=> $r1);
  $idx=($s < $f) ? -$s+$r1 : ($dx=-$dx,$s-$r1);
  while ( @ret <= abs($r2-$r1) ) {
    push @ret,$ary->[$idx];
    $idx+=$dx;
  }
  return @ret;
}


# Excluding sub {} wrapper its 126 bytes.
#         1         2         3         4         5         6         
+7
#123456789012345678901234567890123456789012345678901234567890123456789
+012345678
sub subrange_no_error {
 my($p,$q,$Y,$s,$f)=@_;my($d,$i,@r)=($q<=>$p);$i=($s<$f)?-$s+$p:($d=-$
+d,$s-$p);
 push(@r,$Y->[$i]),$i+=$d while@r<=abs($q-$p);@r;
}

#180 bytes (counting newline used as mandatory whitespace as one char)
sub subrange_golf_error {
 my($p,$q,$Y,$s,$f)=@_;my($d,$i,@r)=($q<=>$p);$i=($s<$f)?-$s+$p:($d=-$
+d,$s-$p);
 ($_<$s&&$_<$f||$_>$s&&$_>$f)&&die"Bad range!"for$p,$q;push(@r,$Y->[$i
+]),$i+=$d
 while@r<=abs($q-$p);@r;
}

# this is now just a wrapper to subrange. Its just for testing and int
+erface
# compatibility
sub arrange {
  my $href=shift;
  my @ret= subrange_golf_error(@{$href->{subrange}},$href->{arr},@{$hr
+ef->{range}});
    $href->{ret}=\@ret;
  unless (defined wantarray) {
    my $idx=$href->{range}[0];
    my $dx=$href->{range}[1] <=> $href->{range}[0];
    print "Subrange @{$href->{subrange}} of Array [".
          join(", ", map{ my $r="$idx:$_"; $idx+=$dx; $r } @{$href->{a
+rr}})
          ."] is <@ret>\n";
  } else{
    return wantarray ? @ret : \@ret;
  }
}

foreach my $t ([5,8],[8,5],[6,5],[6,7],[5,6],[7,6],[1,2],[8,9]) {
  foreach my $r ([8,5],[5,8]) {
    eval {
      arrange({
        arr => [qw(cero uno dos tres)],
        range => $r,
        subrange =>$t
      });
      1
    } or warn "Test @$t failed on range @$r:\n$@";
  }
}
[download]

Cheers

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