Swapping two parts of a string

[Harch84]

Hi Monks I need your valued help again. I have a string which is passed to a perl variable from a html/javascript and returns a set of coordinates. An example of one of these coordinate strings would be this:

(55.950254, -3.187606)

Now what I need to do is to get rid of the comma in this string and then to take the first part of coordinate "55.950254" and put it in front of the other part "-3.187606". The output should look like this:

(-3.187606 55.950254)

I have managed to get rid of the comma using this command in Perl:

$origin =~ s/,//;

... but im not sure how I could swap the two strings around using perl? If it helps both parts should be exactly 9 characters long.
Thanks for your help

[FunkyMonk]

my $input = "(55.950254, -3.187606)";
( my $output = $input ) =~ s{([-\d.]+),  # capture the first number to
+ $1
                             \s+         # at least one space
                             ([-\d.]+)   # capture the second to $2
                            }
                            {$2 $1}x;     # reverse $1 & $2

print $output;

See perlre and perlretut for help with regular expressions, and Regexp Quote-Like Operators in perlop for s///.

update: added references to documentation

[grep]

FWIW a non regex answer

my $input = "(55.950254, -3.187606)";
my $result = '('.join(' ',reverse(split(/[(),]/,$input))).')';

[GrandFather]

Capture the two strings to be swapped using a regex then put them back together in opposite order:

$origin =~ s/\( ([^ ,]+) \s*,\s* ([^ )]+) \) /($2 $1)/x;

Note that the /x allows the spaces to be used to break up the expression for easier understanding.

[Harch84]

Hey thanks for the quick replies guys they have been a big help!

[robot_tourist]

I have nothing to add except: cool, the Royal Mile!

[oxone]

Here's a much worse way to do this, which is neither big or clever (although it does work):

my $input = "(55.950254, -3.187606)";
(my $result = join ' ', eval "reverse$input" ) =~ s/(.*)/($1)/;