I swear I've had this work before, but not today. I have a GLOBREF held in a lexical scalar. I can assign new values to the GLOBs SCALAR, ARRAY & HASH slots, independantly of each other just fine.

Now I need to add or modify the CODE slot, without affecting the existing values in the other slots. I've tried various syntaxes, including some stupid ones, but nothing work? 

#! perl -slw
use strict;
no warnings 'uninitialized'; ## supress expected warnings

## Place a globref into a lexical scalar
my $glob = \ do{ local *GLOB; };

print "\$glob = ", $glob;

print "$_ => ", *$glob{ $_ }, ' => ',
    $_ eq 'SCALAR' ? ${ *$glob } :
    $_ eq 'ARRAY'  ? join ', ', @{ *$glob } :
    $_ eq 'HASH'   ? join ', ', %{ *$glob } :
#    $_ eq 'CODE'   ?            &{ *$glob } : ## fatal as CODE slot i
+s empty
    'n/a'
    for qw[ SCALAR ARRAY HASH CODE IO FORMAT ];
print "The scalar slot is initialised to point to undef(?) '${ *$glob 
+}'";

print "\n-------\n\n Now assign some values to the slots\n";


${ *$glob } = 'A scalar';
@{ *$glob } = qw[ an array ];
%{ *$glob } = qw[ This is a hash ];

print $glob;
print "$_ => ", *$glob{ $_ }, ' => ',
    $_ eq 'SCALAR' ? ${ *$glob } :
    $_ eq 'ARRAY'  ? join ', ', @{ *$glob } :
    $_ eq 'HASH'   ? join ', ', %{ *$glob } :
#    $_ eq 'CODE'   ?            &{ *$glob } : 
    'n/a'
    for qw[ SCALAR ARRAY HASH CODE IO FORMAT ];

## HOW TO ASSIGN A VALUE TO THE CODEREF (not overwriting all the other
+ slots!)

## This attempts to invoke the sub
# &{ *$glob } = sub{ print 'Anon 1'; };

## This fails - $glob becomes a REF(0x....)
# *{ *$glob } = sub{ print 'Anon'; };
# print "\n\nAfter \*{ *\$glob } = sub{ ... }: ", $glob;
# >> After *{ *$glob } = sub{ ... }: REF(0x224fe4)

## This fails in the same way
# *$glob = sub{ print 'Anon'; };
# print "\n\nAfter *\$glob = sub{ ... }: ", $glob;
# >> After *$glob = sub{ ... }: REF(0x224fe4)

## And so does this.
# *{ $glob } = sub{ print 'Anon'; };
# print "\n\nAfter \*{ \$glob } = sub{ ... }: ", $glob;
# >> After *$glob = sub{ ... }: REF(0x224fe4)

## This (unsurprisingly) just assigns a normal coderef.
# $glob = sub{ print 'Anon 2'; };
# print "\n\nAfter \$glob = sub{ ... }: ", $glob;
# >> After $glob = sub{ ... }: CODE(0x18623a4)

print "$_ => ", *$glob{ $_ }, ' => ',
    $_ eq 'SCALAR' ? ${ *$glob } :
    $_ eq 'ARRAY'  ? join ', ', @{ *$glob } :
    $_ eq 'HASH'   ? join ', ', %{ *$glob } :
    $_ eq 'CODE'   ?            &{ *$glob } : 
    'n/a'
    for qw[ SCALAR ARRAY HASH CODE IO FORMAT ];

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In reply to Assigning to the CODE slot of a GLOB whose REF is held in a lexical? by BrowserUk

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