Schwartzian transform of %$self ... help?

[Colin Howarth]

Hi all.

Most of my methods start off with something like:

$self = shift;

my $font = $self->{Font};
my $text = $self->{Text};
...

which wastes toner if you have a lot of members.

What I'd like to do is something like

my( map { ${lc $_} } (keys %$self) ) = (values %$self);

but this complains (how dare it!?) thusly:

Can't use global $_ in "my" at PS.pm line 831.

hmmph. Ok, there IS a $_ inside the my(), but I'm not trying to my the $_ am
I? The following irrelevant snippet is ok though:

$text = "Boo :-)"; $font = "Helvetica"; $size = 20;
print ( map { ${lc $_} } (Text, Font, Size) );

Any ideas?

Thanks,

colin

[Matt DiMeo]

In article <4rb8tm$1...@colin.muc.de>, Colin Howarth <co...@muc.de> wrote:
> my $font = $self->{Font};
> my $text = $self->{Text};

I'd construct a string containing all those commands and eval() it.

If you don't want to do this at run time for every method call, you can
construct entire functions as strings, and eval() *them* to define the
functions.

Another (IMHO better but slower [function call overhead]) possibility
would be to create a series of functions font(), text(), etc.,
and use them as methods instead of using $font, etc.

With the short module at the end of this posting, you can say

use Bt::Access_func "Mypackage" qw(Font Text) ;

And get $self->Font and $self->Text as methods in object Mypackage,
basically for free. This module uses the create-functions-as-
strings-and-eval() methodology. With minimal changes, you can make
it generate lowercased method names, if you prefer.

Enjoy,
-m@

# use Bt::Access_func "packagename", qw(field1 field2 field3 ...)
# Generates access routines for the $self->{'field'} entries for another
# object "packagename".

package Bt::Access_func ;

use strict ;
sub import {
my ($mypackage, $targpackage, @kw) = @_ ;
my ($evalstr) = "" ;
my ($word) ;

foreach $word (@kw) {
$evalstr .=<<EOT ;
sub $targpackage\::$word { \$_[0]->{'$word'} }
EOT

}

eval $evalstr ;
}

1;

[Randal L. Schwartz]

>>>>> "Colin" == Colin Howarth <co...@muc.de> writes:

Colin> Hi all.
Colin> Most of my methods start off with something like:

Colin> $self = shift;

Colin> my $font = $self->{Font};
Colin> my $text = $self->{Text};
Colin> ...

Colin> which wastes toner if you have a lot of members.

I'd just do this:

{
package TestDummy;
use Alias; # found in the CPAN
sub new {
bless {
Font => "font".time,
Text => "text".time,
}, shift;
}

sub versive {
my $self = attr shift;
print "for $self, Font is $Font and Text is $Text\n";
}
}
$thing = new TestDummy;
versive $thing;

The CPAN is your friend. Use the CPAN.

print "Just another Perl hacker," # but not what the media calls "hacker!" :-)
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