Regexp cannot be used to format data, but you could pair up regexps and format data:

%patterns = (
   t => [
      qr/^t\((\d+);(\d+)\)\(([p|q]\d+);([p|q]\d+)\)$/,
      't(%d;%d)(%s;%s)'
   ],
   inv => [
      qr/^inv\((\d+)\)\(([p|q]\d+)([p|q]\d+)\)$/,
      'inv(%d)(%s%s)'
   ],
   '+' => [
      qr/^\+(\d+)$/,
      '+%d'
   ]
);
   
my @parsed;

foreach (
   't(1;3)(q15;p13)',
   'inv(1)(p13p11)',
   '+3',
) {
   my $class;

   foreach my $class (keys(%patterns)) {
      my @fields;
      @fields = /$patterns{$class}[0]/
         and push(@parsed, [ $class, \@fields ]);
   }
}

foreach (@parsed) {
   my ($class, $fields) = @$_;
   printf($patterns{$class}[1], @$fields);
   print(" is of class $class.\n");
}


__END__
t(1;3)(q15;p13) is of class t.
inv(1)(p13p11) is of class inv.
+3 is of class +.
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If you have formal specifications for all the formats then you can parse the formats to generate matching regex's and printf format strings.

Sketch code would look something like:

my $format = ...;
my $printfStr;
my $regexStr;
my $paramCount;

while ($format)
  {
  my ($chunk) = $format =~ s/^(.*?|\[.*?])(?:\[|$)//g;
  if ($chunk =~ /^\[int]/)
    {# match an int
    $printfStr .= "%d";
    $regexStr .= "(\\d+)";
    ++$paramCount;
    }
  elsif ...
  else
    {# match the text
    $printfStr .= $chunk;
    $regexStr .= "\Q$chunk\E";
    }
  }
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Note that you may need to handle variable whitespace and case indesnsitivity and maybe even nesting of format string elements.