#! perl -slw
use strict;

my $re_dur_years   = qr[ (?<= P     ) \d+ Y ]x;
my $re_dur_months  = qr[ (?<= [PY]  ) \d+ M ]x;
my $re_dur_days    = qr[ (?<= [PYM] ) \d+ D ]x;
my $re_dur_hours   = qr[ (?<= [T]   ) \d+ H ]x;
my $re_dur_minutes = qr[ (?<= [TH]  ) \d+ M ]x;
my $re_dur_seconds = qr[ (?<= [THM] ) \d+ (?: \. \d+ )? S ]x;
my $re_dur = qr[^
	-? P (?= T? -? \d+ )
	(?:	$re_dur_years?
	|	$re_dur_months?
	|	$re_dur_days?
	(?: T
		(?:
		|	$re_dur_hours
		|	$re_dur_minutes
		|	$re_dur_seconds
		){1,3}
	)?
	){1,6}
$]x;

while( <DATA> ) {
	chomp;
	print and next if m[^\s*$];
	printf "%s %s\n", $_, 
	    $_=~ $re_dur ? 'matched' : 'didn\'t match';
}


__DATA__
P
P1Y
P1Y1M
P1Y1M1D
P1Y1M1DT1H
P1Y1M1DT1H1M
P1Y1M1DT1H1M1S
P1Y1M1DT1H1M1.1S
P1M1DT1H1M1.1S
P1DT1H1M1.1S
PT1H1M1.1S
PT1M1.1S
PT1.1S
PT0.1S

P-
P-1Y
P-1Y-1M
P-1Y-1M-1D
P-1Y-1M-1DT-1H
P-1Y-1M-1DT-1H-1M
P-1Y-1M-1DT-1H-1M-1S
P-1Y-1M-1DT-1H-1M-1.1S
P-1M-1DT-1H-1M-1.1S
P-1DT-1H-1M-1.1S
PT-1H-1M-1.1S
PT-1M-1.1S
PT-1.1S
PT-0.1S

P1H
P1M1Y
P1D1M
P1DT1M
PT1Y
PT1M
PT1D
PT1S1M
PT1M1H

-P1Y
P3Y3M3DT3H3M3S
P3M3Y3DT3H3M3S
P334Y3DT3H3M3S
PT2H
5T
PT
P5M6DT
P5M6DT9
P600T6S