#!/usr/bin/perl
our @fields;
use mem(@fields=qw(one two three));
use Data::Vars \@fields, {one=>1, two=>2, three=>3};
use P;

my $self=main->new();

P "one=%s, two=%s, three=%s", $self->one, $self->two, $self->three;

##</code><code>##

> /tmp/t.pl
one=1, two=2, three=3

##</code><code>##

> /tmp/t.pl
Can't modify logical and (&&) in lvalue subroutine return at /Users/law.Bliss/bin/lib/Data/Vars.pm line 108, near "}"
BEGIN not safe after errors--compilation aborted at /Users/law.Bliss/bin/lib/Data/Vars.pm line 111.
Compilation failed in require at /tmp/t.pl line 4.
BEGIN failed--compilation aborted at /tmp/t.pl line 4.

##</code><code>##

  sub _Var ($$$;$) :lvalue {                  # Wrkhorse code for manufctrd Vars
    my ($p, $vn, $wa) = @{(shift)};           # vn=varname
    my $c = ref $p || $p;
    my $rfv = ref $p->{$vn};                  # rfv=ref(type) of var
    my $addrof;
    if ($wa && $wa eq '&#945;') { $wa=undef, $addrof=1 }
    my $arg = $_[0];
    if (@_ && !$addrof)  {                    # arg for "setter"
      my $rfa = ref $arg;                     # ref of the arg
      unless ( defined($p->{$vn}) && defined $arg ){  # if both not defined
        $p->{$vn} = $arg }

      elsif ($rfv eq ARRAY) {                 ## if type(var)==ARRAY, 1 param
        my ($index, $ap) = (shift, $p->{$vn});
        if ($p->{':pusharray'} or ( !looks_like_number($index) ||
            not( (defined $wa) || @_) )) {
          push @{$p->{$vn}}, ($index);            ## convert to "push"
          return $index }                         ## return pushed value

        else {
          $p->{$vn}[$index] = $_[0] if @_;
          return $p->{$vn}[$index] if defined $wa } }

      elsif ($rfv eq HASH) {              
        my $subvar = shift;                     ## 1 var w/hash is is a key
        $p->{$vn}{$subvar} = $_[0] if @_;       ## another?  =>assign value
        return $p->{$vn}{$subvar} if defined $wa }
      
      else {
        if ((length $rfv) && $rfv ne $rfa ) {   ## incompat assignment
          warn P "Warning: var type redefined from \"%s\" to \"%s\"",
                  $rfv, $rfa }

        $p->{$vn} = $_[0];                    ## assignment is default
        return $p->{$vn} if defined $wa } }   # how to return results? (below)

    if ($rfv eq ARRAY ) {
      if (defined($wa)) {               # arrays  special
        $wa? @{$p->{$vn}} : $addrof ? \$p->{$vn} : $p->{$vn} } }

    elsif ($rfv eq HASH ) { $p->{$vn} } 
    elsif ($addrof) { return $p->{$vn} }
    else  { return $p->{$vn} }
  } ## endsub (#108)
  
  # "address(ref)-of" function (
  sub _addr_of_($) { (#111 -- basically next line of code)


##</code><code>##

can't modify logical and (&&) in lvalue subroutine return.

##</code><code>##

> perl -d bin/dedup

Loading DB routines from perl5db.pl version 1.33
Editor support available.

Enter h or `h h' for help, or `man perldebug' for more help.

Can't modify logical and (&&) in lvalue subroutine return at /Users/law.Bliss/bin/lib/Data/Vars.pm line 108, near "}"
BEGIN not safe after errors--compilation aborted at /Users/law.Bliss/bin/lib/Data/Vars.pm line 144.
 at /Users/law.Bliss/bin/lib/Data/Vars.pm line 144.
        require Data/Vars.pm called at bin/dedup line 21
        main::BEGIN() called at /Users/law.Bliss/bin/lib/Data/Vars.pm line 144
        eval {...} called at /Users/law.Bliss/bin/lib/Data/Vars.pm line 144
Compilation failed in require at bin/dedup line 21.
 at bin/dedup line 21.
        main::BEGIN() called at bin/dedup line 21
        eval {...} called at bin/dedup line 21
BEGIN failed--compilation aborted at bin/dedup line 21.
 at bin/dedup line 21.
Debugged program terminated.  Use q to quit or R to restart,
  use o inhibit_exit to avoid stopping after program termination,
  h q, h R or h o to get additional info.
  DB<1>

##</code><code>##

  BEGIN { #140
    if (require "Dbg.pm") {   # import if there, else not; no error if not using TPe
      Dbg->import;
    } #143
  }  #144

##</code><code>##

use Data::Vars \@fields, {mmap=>1, aio_respQ=>{}, examine_paths=>[], SYS_IO=>1,
			  use_child_ra=>1};

##</code><code>##

$a==NULL && $a=xxx; (needs parens or 'and' instead of '&&').