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Everybody seems to be happy with the presence of defined-or (//) operator in Perl 5.10, including me. As I often write:
my $default = 0; my $input_number = $ARGV[0]; my $number = defined $input_number ? $input_number : $default;
Now I can write:
my $number = $input_number // $default;
Lacking of chances to download and install Perl 5.10 and test it myself (which can be read as 'lazy' :-) ), I wonder if any monks have experiences on using this one of new-long-waited-features in sequential. Take a look at this example:
my $default_theme = get_default_theme(); my $global_config = read_config('/path/to/config_file'); my $theme_config = read_config($global_config->{theme_file}); my $current_mode = get_current_mode(); my $theme = defined $global_config->{modes}{$current_mode}{theme} ? $global_config->{modes}{$current_mode}{theme} : defined $theme_config->{current_theme} ? $theme_config->{current_theme} : defined $default_theme ? $default_theme : 'none';
With defined-or operator, can I simply write
my $theme = $global_config->{modes}{$current_mode}{theme} // $theme_config->{current_theme} // $default_theme // 'none';
or, should I use some parens to delimit the (inner) expressions such as,
my $theme = ( ( $global_config->{modes}{$current_mode}{theme} // $theme_config->{current_theme} ) // $default_theme ) // 'none';
Is there any other alternative? Is this possible at all?

Thanks all for sharing your experiences.


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In reply to Sequential defined-or operators by naikonta

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    [ELISHEVA]: I may have to resort to SOPW - but was hoping that this would be something simple
    [erix]: I'd just remove the BOM, it is pretty simple
    [ELISHEVA]: Simple yes. and I did consider that. but this isn't one off . An important data source that I don't control is generating bom prefixed utf8 files and I'd rather not have to be munging files every few months.
    [erix]: on teh other hand a SOPW is pretty much garanteed to get an answer from tux (and probably the module fixed)
    [ELISHEVA]: plus it bugs me that something that *should* be simple, *should* work- unicode and noms aren't exactly the new kids on the block
    [ELISHEVA]: well then since the obvious possible mistakes on my part have been ruled out, SOPW it is.
    [ELISHEVA]: the data source, or one of them, is the OECD - they provide a *lot* of data that ought to be easily available to perl programmers.
    [erix]: it might be cunning to mention the module in the title... :)
    [ELISHEVA]: fancy that - a title that actually describes the problem :-)
    [ELISHEVA]: but actually thanks for the reminder

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