Re^2: Moose roles

I'd like to use array and hash attributes in mixed list and array contexts:

   @list = $obj-> prop;
   $obj->prop(@list);
   $array = $obj->prop;
   $obj->prop($array);
[download]

I though I could do that with "around":

   has prop;
   around prop => \&my_accessor;
[download]

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Re^3: Moose roles by EvanCarroll (Chaplain) on Jan 13, 2010 at 21:58 UTC
# Done with `auto_deref => 1` @list = $obj-> prop; # Done with a custom writer attribute that takes an array, and stores + a reference to it. # internally Moose uses a plain perl hash (most complex datastructure + in perl), this # limits it to not having true non-array properties (but a scalar arr +ay-ref works) $obj->prop(@list); # assuming you mean $arrayRef # Here the getter would have to call wantarray() which is exactly wha +t auto_deref => 1 # will set up for you. $array = $obj->prop; # assuming you mean $arrayRef, this already works so long as the type + is ArrayRef # or, a parent thereof. $obj->prop($array); [download] All you need is a custom attribute setter that takes a list and converts it to an array ref. Because n-parameterized types are not supported (you can't have a type of intStr of type (Int, Str), coercing on a custom type is out the question. (unless your doing something scarry). This leaves a custom writter that does something like. `sub foo_writer { if ( length @_ > 1 ) { \@_ } else { die 'invalid arg' unless ref $_[0] eq 'ARRAY'; $_[0]; } }` [download] read the docs on `has()` writer argument. this is also pseudo code, my writer returns the value, I believe you'd have to explicitly set it though. Evan Carroll The most respected person in the whole perl community. www.evancarroll.com	[reply] [d/l] [select]
Re^4: Moose roles by dk (Chaplain) on Jan 13, 2010 at 22:27 UTC
Thanks Evan, that's more or less what I figured out, I just used "around" instead of combination of "writer" and "auto_deref". Actually, I found a completely another way to approach the problem. I've uploaded a proof of concept to CPAN, when it will be available I'll update the top post. Thanks again!	[reply]


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