Witam!

Napisałem prosty regex do walidowania elementu DOCTYPE dokumentu HTML (standard 5.1 W3C):
[PHP] pobierz, plaintext 
  1. echo "<pre>";
  2.  
  3. 		$regex=<<<'REGEX'
  4. @(*UTF8)^
  5. 	<!((?i)DOCTYPE)
  6. 	(?<space_characters>[\x20\x09\x0A\x0C\x0D])+
  7. 	((?i)HTML)
  8. 	(
  9. 		\g<space_characters>+
  10. 		(
  11. 			(												# DOCTYPE legacy string
  12. 				((?i)SYSTEM)
  13. 				\g<space_characters>+
  14. 				(?<quote_mark>["'])
  15. 				about:legacy-compat
  16. 				\k<quote_mark>
  17. 			)|(												# obsolete permitted DOCTYPE string
  18. 				((?i)PUBLIC)
  19. 				\g<space_characters>+
  20. 				(?<first_quote_mark>["'])
  21. 				(
  22. 					(
  23. 						-//W3C//DTD\ HTML\ 4\.0//EN
  24. 						\k<first_quote_mark>
  25. 						(
  26. 							\g<space_characters>+
  27. 							(?<third_quote_mark_1>["'])
  28. 							<a href="http://www\.w3\.org/TR/REC-html40/strict\.dtd" target="_blank">http://www\.w3\.org/TR/REC-html40/strict\.dtd</a>
  29. 							\k<third_quote_mark_1>
  30. 						)?
  31. 					)|(
  32. 						-//W3C//DTD\ HTML\ 4\.01//EN
  33. 						\k<first_quote_mark>
  34. 						(
  35. 							\g<space_characters>+
  36. 							(?<third_quote_mark_2>["'])
  37. 							<a href="http://www\.w3\.org/TR/html4/strict\.dtd" target="_blank">http://www\.w3\.org/TR/html4/strict\.dtd</a>
  38. 							\k<third_quote_mark_2>
  39. 						)?
  40. 					)|(
  41. 						-//W3C//DTD\ XHTML\ 1\.0\ Strict//EN
  42. 						\k<first_quote_mark>
  43. 						\g<space_characters>+
  44. 						(?<third_quote_mark_3>["'])
  45. 						<a href="http://www\.w3\.org/TR/xhtml1/DTD/xhtml1-strict\.dtd" target="_blank">http://www\.w3\.org/TR/xhtml1/DT...trict\.dtd</a>
  46. 						\k<third_quote_mark_3>
  47. 					)|(
  48. 						-//W3C//DTD\ XHTML\ 1\.1//EN
  49. 						\k<first_quote_mark>
  50. 						\g<space_characters>+
  51. 						(?<third_quote_mark_4>["'])
  52. 						<a href="http://www\.w3\.org/TR/xhtml11/DTD/xhtml11\.dtd" target="_blank">http://www\.w3\.org/TR/xhtml11/D...tml11\.dtd</a>
  53. 						\k<third_quote_mark_4>
  54. 					)
  55. 				)
  56. 			)
  57. 		)
  58. 	)?
  59. 	\g<space_characters>*
  60. 	>
  61. $@suxDX
  62. REGEX;
  63.  
  64. 		echo "0 - ";var_dump(preg_match($regex, '<!DOCTYPE>'));
  65. 		echo "0 - ";var_dump(preg_match($regex, '<!DOCTYPE 	   >'));
  66. 		echo "1 - ";var_dump(preg_match($regex, '<!DOCTYPE	htmL>'));
  67. 		echo "1 - ";var_dump(preg_match($regex, '<!DOCTYPE htmL	 >'));
  68. 		echo "0 - ";var_dump(preg_match($regex, '<!DOCTYPE htmL	 SYSTEM>'));
  69. 		echo "1 - ";var_dump(preg_match($regex, '<!DOCTYPE htmL	 SYSTEM \'about:legacy-compat\'   	 	 	>'));
  70. 		echo "1 - ";var_dump(preg_match($regex, '<!DOCTYPE htmL	 SYSTEM "about:legacy-compat">'));
  71. 		echo "0 - ";var_dump(preg_match($regex, '<!DOCTYPE htmL	 SYSTEM "about:legacy-compat\'>'));
  72. 		echo "0 - ";var_dump(preg_match($regex, '<!DOCTYPE htmL	 PUBLIC "about:legacy-compat">'));
  73. 		echo "1 - ";var_dump(preg_match($regex, '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">'));
  74. 		echo "0 - ";var_dump(preg_match($regex, '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//en">'));
  75. 		echo "0 - ";var_dump(preg_match($regex, '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//PL">'));
  76. 		echo "1 - ";var_dump(preg_match($regex, '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN"	  	\'http://www.w3.org/TR/REC-html40/strict.dtd\'>'));
  77. 		echo "0 - ";var_dump(preg_match($regex, '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN"	  	\'http://www4w3.org/TR/REC-html40/strict.dtd\'>'));
  78. 		echo "0 - ";var_dump(preg_match($regex, '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"	  	\'http://www.w3.org/TR/REC-html40/strict.dtd\'>'));
  79. 		echo "1 - ";var_dump(preg_match($regex, '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">'));
  80. 		echo "1 - ";var_dump(preg_match($regex, '<!DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"		>'));
  81. 		echo "0 - ";var_dump(preg_match($regex, '<!DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN">'));
  82.  
  83. 		echo "</pre>";
[PHP] pobierz, plaintext
jednak zaobserwowałem, że część kodu obsolete permitted DOCTYPE string powtarza się w większości i tutaj moje pytanie, jak to wyrażenie uprościć?
Myślałem nad cachem third_quote_mark, ale nie mogę tego zrobić dla typu tabelarnego.
Macie może jakiś pomysł?