To continue to use \n, use a list with print ...

Yes. Although I'd use a separate line for clarity

print Dumper $data_structure;
print "\n";
[download]

Just use say:

say Dumper $data_structure;
[download]

say outputs a trailing newline unless the arguments already contain a trailing newline.

I just feel that is clearer and less prone to the sort of error I created.

I'm no Lisp guy, but using a few more brackets helps to avoid ambiguity and misunderstandings between humans and computers. If you call a function or method, add brackets around the argument list. That's what I do, with only very few exceptions - mostly stuff that is listed in perlfunc, but behaves more like a keyword or a C macro (__FILE__, __LINE__, __PACKAGE__, do, eval, package, use, require) than like a function.

I would have written ...

say Dumper($data_structure);
[download]

... in code for perl 5.10 and newer (i.e. with use v5.10 in the file), or ...

print Dumper($data_structure),"\n";
# or
print Dumper($data_structure)."\n";
[download]

... in code for older perls.

Alexander

say outputs a trailing newline unless the arguments already contain a trailing newline.

Are you sure about that? The documentation makes no mention of such a condition and this example suggests that it is not the case:

$ cat say.pl 
#!/usr/bin/env perl 
use strict;
use warnings;
use feature 'say';

my $x = "foo\n";
my $y = 'bar';

say $x;
say $y;
$ ./say.pl 
foo

bar
$
[download]

---

🦛

say outputs a trailing newline unless the arguments already contain a trailing newline.

Are you sure about that? The documentation makes no mention of such a condition and this example suggests that it is not the case:

D'oh! Of course, you are right, say simply appends a newline, and that's also what's written in the documentation.

The "add a newline unless there is already one" is my mental model of say, and my code never proved me wrong - because I never called it with a string already containing a trailing newline. And to make things worse, I even linked to the documentation in Re^5: Data::Dumper output. I wonder why my mental model of say is wrong. A blame on perlfunc states that the documentation hasn't changed for two years, and has no relevant changes since say was introduced.

Alexander

--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)