Re^8: Experimental features: autoderef vs postfix deref

Having a background in C, I use "static" variables a lot. So, to me, Perl's "state" variables are the same thing.

(Also, I think it makes the usage clearer to the code reviewers and potential future code maintainers.)

(When I have real use case for a closure, I will code it that way. If it's just to "simulate" a "static" variable, I would rather use "state".)

Comment on Re^8: Experimental features: autoderef vs postfix deref

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Re^9: Experimental features: autoderef vs postfix deref by golux (Chaplain) on Jul 14, 2015 at 18:01 UTC
RonW, I also have a C background, and agree about "state" variables being the Perl equivalent of C "static" variables. Using "state" simplifies cases like the following where one shouldn't have to remember to print an HTML header, but also doesn't want it more than once: `#!/usr/bin/perl use strict; use warnings; use feature qw{ state }; sub html { my ($text) = @_; # Make the header idempotent state $b_header++ or print "Content-type: text/html\n\n"; print $text; } html("<br>This is some html, prior to which a header is printed\n"); html("<br>This is too (but the header was printed already)\n");` [download] Output: `Content-type: text/html <br>This is some html, prior to which a header is printed <br>This is too (but the header was printed already)` [download] say substr+lc crypt(qw $i3 SI$),4,5	[reply] [d/l] [select]

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Re^9: Experimental features: autoderef vs postfix deref
by golux (Chaplain) on Jul 14, 2015 at 18:01 UTC

Using "state" simplifies cases like the following where one shouldn't have to remember to print an HTML header, but also doesn't want it more than once:

#!/usr/bin/perl

use strict;
use warnings;
use feature qw{ state };

sub html {
    my ($text) = @_;

    # Make the header idempotent
    state $b_header++ or print "Content-type: text/html\n\n";

    print $text;
}

html("<br>This is some html, prior to which a header is printed\n");
html("<br>This is too (but the header was printed already)\n");
[download]

Output:

Content-type: text/html

<br>This is some html, prior to which a header is printed
<br>This is too (but the header was printed already)
[download]

say substr+lc crypt(qw $i3 SI$),4,5

[reply]
[d/l]
[select]