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Re^3: Dynamically Changing Packages w/out Eval

by shmem (Canon)
on Jun 22, 2009 at 12:05 UTC ( #773589=note: print w/ replies, xml ) Need Help??

in reply to Re^2: Dynamically Changing Packages w/out Eval
in thread Dynamically Changing Packages w/out Eval

Perhaps copying and restoring the symbol table does what you want?

use Data::Dumper; package Foo; $foo="bar"; sub quux { print "\$foo is '$foo'\n" } package main; my %Foo_save = %Foo::; print "-1-\n",Dumper \%Foo::; eval "\$Foo::bar = q{quux}"; print "-2-\n",Dumper \%Foo::; print "-3-\n",Dumper \%Foo_save; %Foo:: = %Foo_save; print "-4-\n",Dumper \%Foo::; Foo::quux(); eval "print \"but Foo::bar is '\$Foo::bar'\\n\""; __END__ -1- $VAR1 = { 'quux' => *Foo::quux, 'foo' => *Foo::foo }; -2- $VAR1 = { 'bar' => *Foo::bar, 'quux' => *Foo::quux, 'foo' => *Foo::foo }; -3- $VAR1 = { 'quux' => *Foo::quux, 'foo' => *Foo::foo }; -4- $VAR1 = { 'quux' => *Foo::quux, 'foo' => *Foo::foo }; $foo is 'bar' but Foo::bar is ''

That fails if eval'ed code populates a scalar slot of an already present typeglob - if, for instance, the subroutine in Foo was named 'bar', then $Foo::bar would retain the value set in the string eval. Hmm.. maybe Clone would help?

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