http://www.perlmonks.org?node_id=1013877

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

In porting yet another C++ wxWidgets example to wxPerl, I had the need to translate a few simple C++ Structures to Perl. I used a hash. Thus C++ data.value becomes Perl $data{value}. Is this the generally accepted method?

Thanks,

James

There's never enough time to do it right, but always enough time to do it over...

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Re: Porting a C/C++ Structure to Perl
by tobyink (Canon) on Jan 17, 2013 at 20:18 UTC

    It can be done that way. The trouble is that hashes don't offer any validation. You could mis-spell it as $data{vaule} somewhere leading to errors which can be hard to detect.

    An object would be more appropriate. $data->vaule will throw an exception if the vaule method does not exist.

    Creating full classes for each struct you need may seem like a lot of work, but there are various CPAN modules to make it easier for you, such as Class::Struct and MooseX::Struct. Here's an example using MooX::Struct (which I am the author of):

    use MooX::Struct
   Point   => [ 'x', 'y' ],
   Point3D => [ -extends => ['Point'], 'z' ],
;

my $origin = Point3D[ 0, 0, 0 ];

    [download]

    PS: if you do wish to continue the hash route, check out Hash::Util's lock_keys function which can be used to restrict which keys a hash can take, reducing the risks of typos.

    perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'
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Re: Porting a C/C++ Structure to Perl
by jmlynesjr (Deacon) on Jan 18, 2013 at 03:11 UTC

    Thanks, tobyink.

    I think I will post the working hash version first and then do the reading necessary to learn enough to implement your suggestion. Since this is a learning exercise, I think it would be better to code the next version "long-hand" before trying the MooX method.

    James

    There's never enough time to do it right, but always enough time to do it over...

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        Thanks for the references, A.M.,

        I have the download version of Modern Perl as well as Learning Perl, Programming Perl, and the Perl Cookbook. I like docs on paper.

        James

        There's never enough time to do it right, but always enough time to do it over...

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