sub str2lit {
   my ($s) = @_;
   $s =~ s/([\\',"?])/\\$1/g;
   return $s;
}

sub lit2str{
   my ($s) = @_;
  #$s =~ s/\\([^0-9a-zA-Z])/$1/g;  # Probably better
   $s =~ s/\\([\\',"?])/$1/g;
   return $s;
}
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