I got it to do most of what I wanted it to: you reference the members as scalars; you can execute whatever code you want; if you refer to a variable that isn't a member name, it uses the ordinary variable (in fact, if you have a lexical with the same name, it will ignore the member).

But you have to turn off strict, and it definitely pollutes the main namespace (or another namespace, if you litter your code with package statements). So I don't really recommend it, but it can be done.. 

use warnings;

my %hash = (foo => 'bar', a => 'x');

sub with (\%&) {
  my ($href, $cref) = @_;
  *$_ = \$href->{$_} for keys %$href;
  $cref->();
}

print "$_: $hash{$_}\n" for keys %hash;

my $z = 6;

with %hash,
  sub {
    print "** $foo **!\n";
    $a = 5;
    $z = 'changed lexical';
  }
;

print "$_: $hash{$_}\n" for keys %hash;
print "Z is $z\n";

[download]
Update: got rid of string eval, at least.
Caution: Contents may have been coded under pressure.

In reply to Re: Duplicating Pascal's with statement in Perl for anonymous data structures by Roy Johnson
in thread Duplicating Pascal's with statement in Perl for anonymous data structures by Popcorn Dave

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.