YAML::Syck and blessed references of scalars

dgaramond2 has asked for the wisdom of the Perl Monks concerning the following question:

I need to load some "named symbols" which I encode in YAML as:

!var [foo]

which in Perl becomes (bless ['foo'], 'var'), which will be reblessed into the "real" Perl class for later processing. Since these named symbols will be mentioned a lot, I wonder if I can use a simpler syntax like:

!var foo

which can become (bless(do{\(my $o = 'fooz')}, 'var')). Currently YAML::Syck simply load the above as scalars, while Ruby's YAML.rb does interpret this.

Any ideas of simpler syntaxes for my named symbols?

Thanks in advance.

Comment on YAML::Syck and blessed references of scalars

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Re: YAML::Syck and blessed references of scalars by ferreira (Chaplain) on Mar 23, 2007 at 10:54 UTC
Unlike Khen1950fx, I don't expect the syntax for tagged data types to be considered simple. As a matter of fact, YAML::Tiny croaks "YAML::Tiny does not support explicit tags" if you feed them to the module There might be some bug in YAML::Syck which is preventing your case to work (`!var foo`), in contrast to (`!var [foo]`). Because `pirl $> YAML::Syck::Load "--- !!perl/array:var [foo]\n" # long tags $var = bless( [ 'foo' ], 'var' ); pirl $> YAML::Syck::Load "--- !var [foo]\n" # short tags $var = bless( [ 'foo' ], 'var' );` [download] should work just like `pirl $> YAML::Syck::Load "--- !!perl/scalar:var foo\n" # long tags, ok +! $var = bless( do{\(my $o = 'foo')}, 'var' ); pirl $> YAML::Syck::Load "--- !var foo\n" # short tags, :( $var = 'foo';` [download] which it doesn't.	[reply] [d/l] [select]
Re^2: YAML::Syck and blessed references of scalars by dgaramond2 (Monk) on Mar 23, 2007 at 11:55 UTC
Ah, it's a bug then. Submitted to RT. I'll be using the long tag version for now, hoping that YAML::Syck will be fixed soon to support the short version. Thanks!	[reply]
Re: YAML::Syck and blessed references of scalars by Khen1950fx (Canon) on Mar 23, 2007 at 06:16 UTC
For simpler syntaxes, give YAML::Tiny a try. It's designed to read and write YAML-style files with as little code as possible. It has two functions that I think that you can use. The Dump function turns Perl data into YAML, and the Load function turns YAML data into Perl data.	[reply]