Serialization and eval in YAML

throop has asked for the wisdom of the Perl Monks concerning the following question:

Do I need to use eval when reading in a YAML file?

I'm used to serializing with Data::Dumper. It produces a dump string which, when loaded, sets variables to values. E.g:

use Data::Dumper;
@arg2 = [{a => 1, b =>2}], [qw($balloon)];
Data::Dumper->Dump(@arg2)
[download]

gives

'$balloon = {
             \'a\' => 1,
             \'b\' => 2
           };
[download]

When that's printed to a file, and later loaded, $balloon gets set right. But for YAML:

use YAML::XS;
@arg2 = ([{a => 1, b =>2}], [qw($balloon)]);
Dump(@arg2)
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gives

 '---
- a: 1
  b: 2
---
- $balloon
'
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which, when loaded, gives,

0  ARRAY(0x89889e8)
   0  HASH(0x8994130)
      'a' => 1
      'b' => 2
1  ARRAY(0x8ef27c8)
   0  '$balloon'
[download]

Should I just use eval to get $balloon set to the right value? Or is there a YAML function to do this?

Comment on Serialization and eval in YAML Select or Download Code

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Re: Serialization and eval in YAML by Anonymous Monk on Aug 13, 2012 at 17:15 UTC
The YAML interface is nothing like Data::Dumper, use this instead `my $string = Dump $oldbaloon; my $baloon = Load $string;` [download] Or the corresponding DumpFile/LoadFile	[reply] [d/l]
Re: Serialization and eval in YAML by thundergnat (Deacon) on Aug 13, 2012 at 18:15 UTC
use Data::Dumper; @arg2 = [{a => 1, b =>2}], [qw($balloon)]; Data::Dumper->Dump(@arg2) gives '$balloon = { \'a\' => 1, \'b\' => 2 }; Really? Using no version of Perl that I've ever used. `use warnings; use Data::Dumper; @arg2 = [{a => 1, b =>2}], [qw($balloon)]; print Data::Dumper->Dump(@arg2)` [download] Useless use of anonymous list ([]) in void context at dd.pl line 3. $VAR1 = [ { 'a' => 1, 'b' => 2 } ]; Precedence problem. You need parenthesis around the array. And lose the sigil on $balloon. Update: removed some unnecessarily snarky commentary.	[reply] [d/l]
Re^2: Serialization and eval in YAML by Anonymous Monk on Aug 13, 2012 at 20:27 UTC
`use Data::Dumper; print Data::Dumper->Dump( [{a => 1, b =>2}], [qw($balloon)] ); __END__ $balloon = { 'a' => 1, 'b' => 2 };` [download]	[reply] [d/l]