PERL Beginners - tricky hash

Author

tricky hash

Ing. Branislav Gerzo

2005-03-08, 3:57 pm

Hello beginners@perl.org,

anyone could me help with:

use strict;
use warnings;
my %kw = ();
my $kw = \%kw;
for my $cat (split(/\//, 'something/other/foo/bar')) { $kw->{cnt}++; $kw->{cat${kw->{cnt}}} = $cat }

I get: Can't use bareword ("kw") as a HASH ref while "strict refs" in
use..
The goal is to get something like:
$kw->{cat1} = 'something',
$kw->{cat2} = 'other',
$kw->{cat3} = 'foo',
$kw->{cat4} = 'bar'

anyone?

--

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When hell freezes over? I just sold Satan a fur coat the other day...

Manav Mathur

2005-03-08, 3:57 pm

use strict;
use warnings;
use Data::Dumper ;
my %kw = ();
my $kw = \%kw;
my $i = 1;
for my $cat (split(/\//, 'something/other/foo/bar'))
{
$kw->{"cat".eval{$i++}} = $cat
}
print Dumper \%kw ;

-----Original Message-----
From: Ing. Branislav Gerzo [mailto:konfera@2ge.us]
Sent: Tuesday, March 08, 2005 10:14 PM
To: beginners@perl.org
Subject: tricky hash

Hello beginners@perl.org,

anyone could me help with:

use strict;
use warnings;
my %kw = ();
my $kw = \%kw;
for my $cat (split(/\//, 'something/other/foo/bar')) { $kw->{cnt}++;
$kw->{cat${kw->{cnt}}} = $cat }

I get: Can't use bareword ("kw") as a HASH ref while "strict refs" in
use..
The goal is to get something like:
$kw->{cat1} = 'something',
$kw->{cat2} = 'other',
$kw->{cat3} = 'foo',
$kw->{cat4} = 'bar'

anyone?

--

--. ,-- ,- ICQ: 7552083 \|||/ `//EB: www.2ge.us
,--' | - |-- IRC: [2ge] (. .) ,\\SN: 2ge!2ge_us
`====+==+=+===~ ~=============-o00-(_)-00o-================~
When hell freezes over? I just sold Satan a fur coat the other day...

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Wiggins d'Anconia

2005-03-08, 3:57 pm

Ing. Branislav Gerzo wrote:
> Hello beginners@perl.org,
>
> anyone could me help with:
>
> use strict;
> use warnings;
> my %kw = ();
> my $kw = \%kw;
> for my $cat (split(/\//, 'something/other/foo/bar')) { $kw->{cnt}++; $kw->{cat${kw->{cnt}}} = $cat }

You don't have to accept the rope Perl will give you to hang yourself,

$kw->{'cat'.$kw->{'cnt'}} = $cat;

The special quoting Perl does on hash keys is really only useful for
simple strings.

Perl also ignores whitespace for a reason, consider not writing whole
programs on one line, it will help you with debugging.

>
>
> I get: Can't use bareword ("kw") as a HASH ref while "strict refs" in
> use..
> The goal is to get something like:
> $kw->{cat1} = 'something',
> $kw->{cat2} = 'other',
> $kw->{cat3} = 'foo',
> $kw->{cat4} = 'bar'
>
> anyone?
>

http://danconia.org

Ankur Gupta

2005-03-08, 3:57 pm

Lawrence Statton

2005-03-08, 3:57 pm

> Hello beginners@perl.org,
>
>
> I get: Can't use bareword ("kw") as a HASH ref while "strict refs" in
> use..
> The goal is to get something like:
> $kw->{cat1} = 'something',
> $kw->{cat2} = 'other',
> $kw->{cat3} = 'foo',
> $kw->{cat4} = 'bar'
>

Well, fixing the typo where you build the key for the last assignment
would help with your immediate problem. *HOWEVER* You're still
solving the problem in a wrong-way.

*EVERY TIME* you see a list of variable names (or hash keys) of the
form foo1 foo2 foo3 foo4 that should be a GIANT WAVING RED FLAG that
your data model is lacking.

Lacking is not strong enough a word.

How about "is pessimally awful."

"...deserves never to see the light of day."

Perl has a built in data type highly suited for a series of data
indexed by a monotonically increasing integer. The List.

my @keyword = split ( /\//, 'something/wicked/this/way/comes' ) ;

If you like the refence version of it

my $keywords = [ split (/\//, 'something/wicked/this/way/comes') ] ;

-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
Lawrence Statton - lawrenabae@abaluon.abaom s/aba/c/g
Computer software consists of only two components: ones and
zeros, in roughly equal proportions. All that is required is to
sort them into the correct order.

John W. Krahn

2005-03-09, 3:56 am

Ing. Branislav Gerzo wrote:
> Hello beginners@perl.org,

Hello,

> anyone could me help with:
>
> use strict;
> use warnings;
> my %kw = ();
> my $kw = \%kw;
> for my $cat (split(/\//, 'something/other/foo/bar')) { $kw->{cnt}++; $kw->{cat${kw->{cnt}}} = $cat }
>
>
> I get: Can't use bareword ("kw") as a HASH ref while "strict refs" in
> use..
> The goal is to get something like:
> $kw->{cat1} = 'something',
> $kw->{cat2} = 'other',
> $kw->{cat3} = 'foo',
> $kw->{cat4} = 'bar'
>
> anyone?

my $string = 'something/other/foo/bar';
my $count;

my $kw = { map { 'cat' . ++$count, $_ } split /\//, $string };

John
--
use Perl;
program
fulfillment

Ing. Branislav Gerzo

2005-03-09, 3:56 am

John W. Krahn [JWK], on Tuesday, March 08, 2005 at 12:58 (-0800) made
these points:

JWK> my $string = 'something/other/foo/bar';
JWK> my $count;
JWK> my $kw = { map { 'cat' . ++$count, $_ } split /\//, $string };

this is really tricky reply I awaited, I like this solution, really
nice. Also, in my case, the best is:

use strict;
use warnings;
use Data::Dumper ;

my %kw = ();
my $kw = \%kw;
$kw = { map { 'cat' . ++$kw->{cnt}, $_ } split /\//, 'something/other/foo/bar' };
print Dumper $kw;

__END__
$VAR1 = {
'cat2' => 'other',
'cat3' => 'foo',
'cat1' => 'something',
'cat4' => 'bar'
};

Interesting on this is, $kw->{cnt} doesn't exist :)

Thanks to all who replied!

--

...m8s, cu l8r, Brano.

[Is a white person from Africa an African-American?]

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