Re: Bless and Do

The do block defines the logical context of the my declaration. Essentially, we:

define $x
assign the value 49 to it
take a reference
let $x go out of scope
bless the reference
store the reference

Since Perl does not have the concept of an anonymous scalar ref (in contrast to {} and []), your kludge is one way of getting that. The best reason to use it is because it works. The worst reason is that you had to ask the question; it doesn't scan unless you know the trick. Were I to write it, I'd probably go with the more verbose:

my $variable;
ANON_SCALAR_BLOCK: {
    my $x = 49;
    $variable = bless \$x, 'Rates::Notification';
}
[download]

If you really want to use a do, you could also

my $variable = do {
        my $x = 49;
        bless \$x, 'Rates::Notification';
    };
[download]

which I think scans better.

#11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.

Comment on Re: Bless and Do Select or Download Code

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Re^2: Bless and Do by Anonymous Monk on Jun 17, 2014 at 20:20 UTC
An interesting thing to note: Data::Dumper uses a form very similar to OP with blessed references. `perl -MData::Dumper -e 'print Dumper bless \((49)[0]), "Rat::Notificat +ion";' $VAR1 = bless( do{\(my $o = 49)}, 'Rat::Notification' );` [download]	[reply] [d/l]
Re^2: Bless and Do on the outside by Anonymous Monk on Jun 18, 2014 at 00:00 UTC
If you really want to use a do, you could also `my $variable = do { my $x = 49; bless \$x, 'Rates::Notification'; };` [download] which I think scans better. Yes, do on the outside always scans better, its like creating a sub and calling it immediately, `(sub { ... })->();` except prettier :)	[reply] [d/l] [select]
Re^3: Bless and Do on the outside by LanX (Saint) on Jun 18, 2014 at 00:25 UTC
> Yes, do on the outside always scans better, its like creating a sub and calling it immediately, (sub { ... })->(); except prettier :) To avoid misunderstandings: It's similar but not identical! `DB<106> sub tst { (sub { return 5 })->(); return 10 } DB<107> tst() => 10 DB<108> sub tst { do { return 5 }; return 10 } DB<109> tst() => 5` [download] Like with `map` and `grep` is the block following `do` not an anonymous `sub`! Cheers Rolf (addicted to the Perl Programming Language)	[reply] [d/l]
Re^4: Bless and Do on the outside by Anonymous Monk on Jun 18, 2014 at 01:25 UTC
To avoid misunderstandings: It's similar but not identical! "Like" means "similar" I think dictionary can agree! Like with map and grep is the block following do is not an anonymous sub! Of course we're discussing looks!	[reply]
Re^5: Bless and Do on the outside by LanX (Saint) on Jun 18, 2014 at 01:37 UTC
Re^6: Bless and Do on the outside by Anonymous Monk on Jun 18, 2014 at 01:55 UTC