Hello, misterperl

I wonder whether there is a way for setting pos in s///eg substitution?, I mean like this... 

s/(.)(.)/pos()=pos()-1; $2.$1/eg;
With while loop, I will do like this. 
use strict; use warnings;
my $str="6123457";
while ($str =~ /(.)/g){
    last if pos($str) >= length($str);
    my $p=pos($str);    #backup pos beause overwrite $str afterwards
    my $l=substr($str, pos($str) -1 ,1);
    my $r=substr($str, pos($str),1);
    substr($str, pos($str)-1, 2)
        = ($r >= $l) ? $l.$r : $r.$l ; #replace with lvalue of substr
    print "str=$str\n";
    pos($str)=$p;
}
print "result=$str\n";

[download]
regards.

In reply to Re: rotate a vector with a regex? by remiah
in thread rotate a vector with a regex? by misterperl

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