Re^2: Grabbing Variable Names

Hi,

I'm very interested in your comments about determining if a function has been forward declared but not yet loaded, e.g., when using AutoLoader. For some reason, though, I can't get this to work. Here's my test case:

sub hello;
*fn = $::{'hello'};
print "declared\n" if *fn{CODE};
print "not defined\n" if ! defined &fn;
print "exists\n" if exists &fn;
print "glob exists\n" if exists $::{'hello'};
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For me, this test correctly prints "not defined" and "glob exists" but shouldn't it also print "declared" and "exists?"

Thanks for any insight you can give me on this.

Best,
Mike

Comment on Re^2: Grabbing Variable Names Download Code

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Re^3: Grabbing Variable Names
by ihb (Deacon) on Mar 30, 2005 at 21:19 UTC

Long story short is that a forward declaration doesn't create a glob. You can try this by doing

sub foo;
print ref \$::{foo}; # "SCALAR"

sub bar { 1 };
print ref \$::{bar}; # "GLOB"

sub baz;
print ref \$::{baz}; # "GLOB"
$baz = $baz;         # Just to mention the symbol "baz".
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*fn = $::{hello}

-1

*fn

*{-1}

*{something}

*something

&{subname}

sub foo;
*{-1} = sub { 'oh' };     # Create a sub called "-1".
print &{-1}();            # "oh"
*bar = $::{foo};          # Really?
print defined &bar;       # "1" Huh? So now &bar is defined
                          # even though &foo isn't?
print bar();              # "oh"

#$foo;                    # But all this would change if you
                          # uncommented "$foo;".
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ihb

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