Hash's Regex Transformation with Map

[Edward WIJAYA]

Hi all,

How can I make my snippet below:


$ perl -MData:umper -e '
$h = {"A[TCG]GG 3" => foo, "CTG[AA] 2" => bar};
%nh = map { my $k =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});
print Dumper \%nh;'

To produce:

$VAR1 = {
'ASGG 3' => 'foo',
'CTGS 2' => 'bar',
};

Principally I want to change the key of the old hash by
replacing bracketed strings with "S".

 

[Gunnar Hjalmarsson]

How can I make my snippet below:


$ perl -MData:umper -e '
$h = {"A[TCG]GG 3" => foo, "CTG[AA] 2" => bar};
%nh = map { my $k =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});
print Dumper \%nh;'

To produce:

$VAR1 = {
'ASGG 3' => 'foo',
'CTGS 2' => 'bar',
};

For a start, you'd better ask Perl for help:

$ perl -wMData:umper -e ...
------------^

Personally, when the output from a code snippet differs from what you
had expected, I don't think that one-liners should be posted here. By
writing the program in a file and enabling strictures, there is a good
chance that you find your mistake.

 

[robic0]

Hi all,

How can I make my snippet below:


$ perl -MData:umper -e '
$h = {"A[TCG]GG 3" => foo, "CTG[AA] 2" => bar};
%nh = map { my $k =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});
print Dumper \%nh;'

To produce:

$VAR1 = {
'ASGG 3' => 'foo',
'CTGS 2' => 'bar',
};

Principally I want to change the key of the old hash by
replacing bracketed strings with "S".

Have to copy $_ in the map statement otherwise $h gets altered.
I would not create a variable to anonymous reference this way
unless it is going to be passed to subroutines alot or creating
a class. Reserve anonymous array/hash references for array elements.
Just my opinion.....

use strict;
use warnings;
use Data:umper;

#my $h = {'A[TCG]GG 3' => 'foo', 'CTG[AA] 2' => 'bar'};
#my %nh = map { my $k=$_; $k =~s/\[[ATCG]+\]/S/g; $k=> $h->{$_} }
(keys %{$h});

my %h = ('A[TCG]GG 3' => 'foo', 'CTG[AA] 2' => 'bar');
my %nh = map { my $k=$_; $k =~s/\[[ATCG]+\]/S/g; $k=> $h{$_} } (keys
%h);

print Dumper \%nh;
#print Dumper $h;
print Dumper \%h;

------------------------
output:

$VAR1 = {
'ASGG 3' => 'foo',
'CTGS 2' => 'bar'
};
$VAR1 = {
'CTG[AA] 2' => 'bar',
'A[TCG]GG 3' => 'foo'
};

 

[Glenn Jackman]

Hi all,

How can I make my snippet below:


$ perl -MData:umper -e '
$h = {"A[TCG]GG 3" => foo, "CTG[AA] 2" => bar};
%nh = map { my $k =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});
print Dumper \%nh;'

$k is undefined

%nh = map { ($k = $_) =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});
-------------------^^^^^

 

[robic0]

Hi all,

How can I make my snippet below:


$ perl -MData:umper -e '
$h = {"A[TCG]GG 3" => foo, "CTG[AA] 2" => bar};
%nh = map { my $k =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});
print Dumper \%nh;'

$k is undefined

%nh = map { ($k = $_) =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});

^^
Yeah but get the can't use global in "my ($k = $_)" since $_ is
global and declared elsewhere (if strict).

 

[Tad McClellan]

Hi all,

How can I make my snippet below:


$ perl -MData:umper -e '
$h = {"A[TCG]GG 3" => foo, "CTG[AA] 2" => bar};
%nh = map { my $k =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});
print Dumper \%nh;'

$k is undefined

%nh = map { ($k = $_) =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});

^^
Yeah but get the can't use global in "my ($k = $_)"

Did you try it?

Did in not work when you did?

since $_ is
global and declared elsewhere (if strict).

The built-in variables need not be declared, even under "use strict".

 

[Glenn Jackman]

%nh = map { ($k = $_) =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});

^^
Yeah but get the can't use global in "my ($k = $_)" since $_ is
global and declared elsewhere (if strict).

You want "(my $k = $_)" then.

 

[robic0]

%nh = map { ($k = $_) =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});

^^
Yeah but get the can't use global in "my ($k = $_)" since $_ is
global and declared elsewhere (if strict).

You want "(my $k = $_)" then.

Ahhh so thats it. I found this an odd error since apparently the
"=" sign passed the syntax check before the global.
So the construct "my ($k = $z) =~ s/aaaa/asdf/g" would be ok then?
It also seems odd that multiple single value assignments would cause
a error also: "my $k=$z=0;" or I remember it gives me errors.

 

[Tad McClellan]

So the construct "my ($k = $z) =~ s/aaaa/asdf/g" would be ok then?

What happened when you tried it?

It also seems odd that multiple single value assignments would cause
a error also: "my $k=$z=0;" or I remember it gives me errors.

It would be a strict message, because you have not declared $z.

 

[Anno Siegel]

Hi all,

How can I make my snippet below:


$ perl -MData:umper -e '
$h = {"A[TCG]GG 3" => foo, "CTG[AA] 2" => bar};
%nh = map { my $k =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});
print Dumper \%nh;'

$k is undefined

%nh = map { ($k = $_) =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});

^^
Yeah but get the can't use global in "my ($k = $_)"

Did you try it?

Did in not work when you did?

my ( $k = $_) =~ ...

does indeed complain about use of global $_ in "my".

( my $k = $_) =~ ...

works.

Anno

 

[robic0]

On 26 Nov 2005 12:47:57 GMT, Glenn Jackman <[email protected]>
wrote:

Hi all,

How can I make my snippet below:


$ perl -MData:umper -e '
$h = {"A[TCG]GG 3" => foo, "CTG[AA] 2" => bar};
%nh = map { my $k =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});
print Dumper \%nh;'

$k is undefined

%nh = map { ($k = $_) =~ s/\[[ATCG]+\]/S/g; $k=> $h->{$_} } (keys %{$h});
^^
Yeah but get the can't use global in "my ($k = $_)"

Did you try it?

Did in not work when you did?

my ( $k = $_) =~ ...

does indeed complain about use of global $_ in "my".

( my $k = $_) =~ ...

works.

Anno

hehe...