use warnings;
use strict;
use Regexp::Common qw/number/;
use Data::Dump;  #Debug

while (<DATA>) {
	/^($RE{num}{decimal}\s*){4}$/ or die;
	my @cols = /$RE{num}{decimal}/g;
	dd @cols;  #Debug
}

__DATA__
1.234 5.6789 -1.235-4
1.234 5.6789-12.235-4

##</code><code>##

(1.234, 5.6789, -1.235, -4)
(1.234, 5.6789, -12.235, -4)

##</code><code>##

$ perl -MRegexp::Common=number -nle '$,=" ";print/$RE{num}{decimal}/g' input.txt >output.txt

##</code><code>##

$ perl -MRegexp::Common=number -pe 's/(?>$RE{num}{decimal})\K(?=$RE{num}{decimal})/ /g' input.txt >output.txt