The following code 

sub channels_by_level { grep { $_[0]->level( $_[1] ) } $_[0]->channels
+ }

[download]

can be written more clear such as: 

sub channels_by_level { 
    my $self  = shift;
    my $level = shift;
    return grep { $self->level( $level ) } $self->channels;
}

[download]

Method $obj->channels_by_level($level) returns those channels which has level given in an argument.

The problem is that your object doesn't have channels. To understand why it doesn't more code need to be shown.

In reply to Re: I don't understand this grep by ccn
in thread I don't understand this grep by gwhite

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