Re^6: Experimental features: autoderef vs postfix deref

While I agree that:

{
    my $state_var;
    sub foo { ...; }
    sub bar { ...; }
}
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is a perfectly valid and common use of closures, I would not want:

sub foo { state $state_var; ...; }
sub bar { state $state_var; ...; }
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to auto-magically assume both (or all at "same" level) declarations of $state_var to be the same variable.

I am pretty sure that state was not designed as a replacement for "traditional" closure constructs, rather just as a short cut for a specific use case.

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Re^7: Experimental features: autoderef vs postfix deref by BrowserUk (Patriarch) on Jul 13, 2015 at 20:05 UTC
I would not want: ... to auto-magically assume both (or all at "same" level) declarations of $state_var to be the same variable. I agree. That would be broken. But having been bitten by having to convert uses of state back to the traditional form; I simply don't think the "convenience" factor is real. It's just not worth the (my) bother. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. I'm with torvalds on this Agile (and TDD) debunked I told'em LLVM was the way to go. But did they listen!	[reply]
Re^8: Experimental features: autoderef vs postfix deref by RonW (Parson) on Jul 13, 2015 at 20:34 UTC
Having a background in C, I use "static" variables a lot. So, to me, Perl's "state" variables are the same thing. (Also, I think it makes the usage clearer to the code reviewers and potential future code maintainers.) (When I have real use case for a closure, I will code it that way. If it's just to "simulate" a "static" variable, I would rather use "state".)	[reply]
Re^9: Experimental features: autoderef vs postfix deref by golux (Chaplain) on Jul 14, 2015 at 18:01 UTC
RonW, I also have a C background, and agree about "state" variables being the Perl equivalent of C "static" variables. Using "state" simplifies cases like the following where one shouldn't have to remember to print an HTML header, but also doesn't want it more than once: `#!/usr/bin/perl use strict; use warnings; use feature qw{ state }; sub html { my ($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]