>perl -wMstrict -le
"my $string =
   qq{uuu\tvvv\t'www\t\t'\txxx\t'\t\tyyy'\tzzz\n};
 print qq{$string};
 ;;
 $string =~
   s{ ( ' [^\\']* (?: \\. [^\\']*)* ' )        }
    { (my $notabs = $1) =~ tr{\t}{}d;  $notabs }xmsge;
 ;;
 print qq{$string};
"
uuu     vvv     'www            '       xxx     '               yyy'    zzz

uuu     vvv     'www'   xxx     'yyy'   zzz

##</code><code>##

use warnings;
use strict;

# check with escaped double-quotes inside and outside
# double-quoted sub-strings.

my $string =
  qq{uuu\t\\"vvv\t"notab\t\t"\txxxx\t"\t\tno\\"tab"\tzzz\n};
print qq{$string};

$string =~
  s{ ((?<! \\) " [^\\"]* (?: \\. [^\\"]*)* ") }
   { (my $notabs = $1) =~ tr{\t}{}d;  $notabs }xmsge;

print qq{$string};

##</code><code>##

uuu     \"vvv   "notab          "       xxxx    "               no\"tab"        zzz
uuu     \"vvv   "notab" xxxx    "no\"tab"       zzz