Dear monks,

I wrote a little script called excelPerl.pl (like xlsPerl, but using Win32::OLE for getting read/write-access to the excel file) which tries to do to an excel file what perl -ane does for a text file, and to keep the interface as similar as possible, I also use the array @F for accessing the cells of one row. Since I want to save changes of elements of @F into the excel file, I decided to use a tied array.

The program works fine, but I couldn't find a clean way to return the tied array from a subroutine so I can use it as array (and not as array reference)

Here a minimal code example returning as arrayref which works:

my $array = TieVariable(); ### Pos1
print "### Initialization finished\n";
for (0..$#$array) {
   print "$_: $array->[$_]\n";
} # for
$array->[6] = 1000;

untie $array;
# ------------------------------------------------------------
sub TieVariable {
   tie my @array, 'Tie::Excel::Array';
   $array[$_] = 5 * $_ for 0..5;

   return \@array; ### Pos2
} # TieVariable

# ============================================================
package Tie::Excel::Array;

sub TIEARRAY {
   my( $class ) = @_;
   return bless [], $class;
} # TIEARRAY
# ------------------------------------------------------------
sub STORE {
   my( $self, $index, $value ) = @_;
   warn "STORE: \$self->[$index] = $value;\n";
   $self->[$index] = $value;
} # STORE
# ------------------------------------------------------------
sub FETCH {
   my( $self, $index ) = @_;
   warn "FETCH: \$self->[$index] = $self->[$index];\n";
   return $self->[$index];
} # STORE
# ------------------------------------------------------------
sub FETCHSIZE {
   my( $self ) = @_;
   return $#$self;
} # FETCHSIZE
# ------------------------------------------------------------
sub UNTIE {
   my( $self ) = @_;
   warn "UNTIE\n";
} # UNTIE
# ...
[download]

Using array

If I just change POS1 to my @array = TieVariable(); and POS2 to return @array; to be able to work with an array in my main program, the array looses its binding, and the change in $array->[6] = 1000; can't be written to the excel file.

Using a global variable

If I use @F as global variable and fill it, it would work; but then I have to know the name of the global variable in the subroutine, and can only use one @F.

Working with an alias

using a package variable and working with something like: our @F; *F = \@MyPackage::Array1;, but then I have to know the variable's name in my main program, and can only use one @MyPackage::Array1

Move the tie into the main program

I like this solution best, but then in the main program you have to know you are working with a tied array

Writing a sourcefilter or similar

Working with the arrayref-solution and writing a source filter which converts accesses to $F[0] to $F->[0] looks much to complicated.

Do you know another solution how I can do it?

The main program of excelPerl.pl should look something like:

# ... parsing parameters: $filename, $perlCode, $separator, ...
my $xls = XlsPerl->new( ... parameters ... );

while( my @F = $xls->getNextRowData ) { ### POS 1
  local $_ = join( $separator, @F );

  eval $perlCode; die $@ if $@;
} # while
[download]

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