The discussion in Efficient partial deep cloning might help.

There are some useful information for me in that discussion, tnx

Thanks for the link, but I have a more complex situation. The above Hashref is not static name. Here's a good example of what I need:

$self = {
   A => {
      B => 'C'
   },
   D => {
      E => {
         F => 'G'
      }
   }
}
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So there are 2 hasrefs in example (in real code there will be more) inside the object. I need this methods to be generated:
• A - would get/set the whole 'A' hashref
• B - would get/set the 'B' key of the 'A' hashref
• D - would get/set the whole 'D' hashref
• E - would get/set the whole 'E' hashref
• F - would get/set the 'F' key of the 'E' hashref

What do you want to do if somewhere in your jungle of hashes you have two keys with the same name?

$self = {
   A => {
      A => 'C'
   },
};
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Does the structure have cycles in it?

package Class::StructAccessors;
use warnings; use strict;

use Scalar::Util qw/reftype/;

sub mk_struct_accessors {
    my ($class, $struct, $path, $key_seen, $ref_seen) = @_;

    $path ||= [];
    $key_seen ||= {};
    $ref_seen ||= {};

    while (my ($k,$v) = each %$struct) {

        my $reftype = reftype($v)||'';
        
        if ($reftype) {
            die "Bad reference type: $reftype"
                unless ($reftype eq 'HASH');
                
            die "Cycle detected at $v"
                if ($ref_seen->{$v});
                
            $ref_seen->{$v} = 1;
            
            $class->mk_struct_accessors($v, [@$path, $k], $key_seen, $
+ref_seen); 
        }
        else {
            die "null key" unless (defined $v && $v ne '');

            die "Duplicate key detected $v"
                if ($key_seen->{$v});
                
            $key_seen->{$v} = 1;
            #
            # add this accessor to the class
            #
            no strict 'refs';
            warn "adding: $v";

            *$v = sub {
                my $self = shift;
                return $self->_dereference(@$path, $k, $v);
            }
       }
  }
}

sub _dereference {
    my $self = shift;
    my @hash_keys = @_;

    my $ref = $self;

    while (@hash_keys && $ref) {
        
        $ref = $ref->{shift(@hash_keys)};
    }
    return $ref;
}

1;
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A test script follows:

package Foo;
use base qw{Class::StructAccessors};
 
__PACKAGE__->mk_struct_accessors({
   A => {
      B => 'C'
   },
   D => {
      E => {
         F => 'G'
      }
   },
##   Z => 'G', # Duplicate test
##   X => [1,2,3], # Bad type test
##   N => do {my $cycle = {}; $cycle->{M} = $cycle; $cycle;}, # Cyclic
+ test
});

package main;
use Foo;

my $obj = bless {
   A => {
      B => {'C' => "It's hello from C"},
   },
   D => {
      E => {
         F => {'G' => "G'day from G"}
      }
   }
}, 'Foo';

print "C:".$obj->C."\n";
print "G:".$obj->G."\n";
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Update: Added test for cycles.

I've read your code attentively, now I want to ask a few questions please. Here:

...
   D => {
      E => {
         F => 'G'
      }
   },
##   Z => 'G', # Duplicate test
...
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If I'll uncomment 'Z' key there will be a warning thrown about duplicate 'G' key. But 'G' is not a key here, it's keys value.

And here:

##   X => [1,2,3], # Bad type test
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Why arrayref is a bad type?

And the last one: I tried to add mutators to your code through assignment the lvalue attribute to _derefernce sub but it has no effect =( Any ideas of how can I do this?

Hi KSURi,

Thanks for your questions. Before getting into the details; I did make some assumptions that need to be tested:

The class level structure (defined in Foo) is a effectively a struct definition:

So, if in Foo, you define

package Foo;
use base qw/Class::StructAccessors/;
__PACKAGE__->mk_struct_accessors({A => {B => C}});
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then the actual method created is C.

my $obj = {};
bless $obj, "Foo";
$obj->{A}{B}{C} = "this is a C";
print $obj->C; # outputs  "this is a C"
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If you want another object with another fixed structure, then you need another class

package Bar;
use base qw/Class::StructAccessors/;
__PACKAGE__->mk_struct_accessors({X => {Y => Z}});
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This will generate accessor method for Z.

In an nutshell, the above code works when you have finite number of structures that are know at run time.

I'm getting the feeling that you want a more dynamic solution that'll work at the instance on any structure; something like:

my $obj = bless {a => {b => {c  => 'data  for c'}}},  "Class::StructAc
+cessorMk2";
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Always happy to assist (and code) :-) Please advise.

Thanks! I'll try your code asap. Unfortunately I can't do this now =(

Having the key Hashref in there may be an indication of a design issue. You may be trying to solve implementation problems stemming from a design problem. Would you care to tell us more about your objects? What other keys are there in your object than Hashref? How about some sample actual data?

Sure, here it is. This is my class constructor which sets primary attributes:

sub new {
    my $class = shift || __PACKAGE__;

    my $self;

    if ( scalar @_ == 1 ) {
        ( $self->{RemoteAddr}, $self->{RemotePort} ) = split( ':', shi
+ft );
    }
    else { $self = {@_} }

    foreach (qw(RemoteAddr RemotePort)) {
        confess $_ . " was not cofigured" unless $self->{$_};
    }

    $self->{FuzzLevel} ||= 1;
    $self->{Debug}     ||= 0;
    $self->{Path}      ||= 'report.html';
    $self->{Report}    ||= 0;
    $self->{Ready}          = 0;
    $self->{Socket}         = undef;
    $self->{LastSentFinger} = undef;

    bless( $self, ref $class || $class );
}
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And these are some additional attributes which will be added later by another sub:

    $self->{FuzzData} = {
        _Letters => {
            __data => [
                        # a lot of data here
            ],
            __example => qr/(\w{1})/
        },
        _Formats => {
            __data => [
                        # again data
            ],
            __example => qr/(%\w{1})/
        },
        _Numbers => {
            __data => [
                        # and again
            ],
            __example => qr/(\d{1)}/
        }
    };

    $self->{ProtoData} = {
        _ActionData => {
            __ActionCmd      => [],
            __ActionExit     => undef,
            __ActionTemplate => undef
        },
        _LoginData => {
            __LoginUser     => undef,
            __LoginPass     => undef,
            __LoginSuccess  => undef,
            __LoginTemplate => undef
        },
        _ProtoPresets => {
            ftp  => \&{ $self->_LoadPresetFTP },
            http => \&{ $self->_LoadPresetHTTP },
            pop3 => \&{ $self->_LoadPresetPOP3 },
            smtp => \&{ $self->_LoadPresetSMTP }
        }
    };
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So, you can notice that attributes are grouped topically

Ok, seems you were right) I've redesigned the object structure and removed all the nested structures. After that it works fine, thank you!