PCRE version 3.7 29-Oct-2001

/(a)b|/
Capturing subpattern count = 1
No options
No first char
No need char

/abc/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'c'
    abc
 0: abc
    defabc
 0: abc
    \Aabc
 0: abc
    *** Failers
No match
    \Adefabc
No match
    ABC
No match

/^abc/
Capturing subpattern count = 0
Options: anchored
No first char
Need char = 'c'
    abc
 0: abc
    \Aabc
 0: abc
    *** Failers
No match
    defabc
No match
    \Adefabc
No match

/a+bc/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'c'

/a*bc/
Capturing subpattern count = 0
No options
No first char
Need char = 'c'

/a{3}bc/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'c'

/(abc|a+z)/
Capturing subpattern count = 1
No options
First char = 'a'
No need char

/^abc$/
Capturing subpattern count = 0
Options: anchored
No first char
Need char = 'c'
    abc
 0: abc
    *** Failers
No match
    def\nabc
No match

/ab\gdef/X
Failed: unrecognized character follows \ at offset 3

/(?X)ab\gdef/X
Failed: unrecognized character follows \ at offset 7

/x{5,4}/
Failed: numbers out of order in {} quantifier at offset 5

/z{65536}/
Failed: number too big in {} quantifier at offset 7

/[abcd/
Failed: missing terminating ] for character class at offset 5

/[\B]/
Failed: invalid escape sequence in character class at offset 2

/[z-a]/
Failed: range out of order in character class at offset 3

/^*/
Failed: nothing to repeat at offset 1

/(abc/
Failed: missing ) at offset 4

/(?# abc/
Failed: missing ) after comment at offset 7

/(?z)abc/
Failed: unrecognized character after (? at offset 2

/.*b/
Capturing subpattern count = 0
No options
First char at start or follows \n
Need char = 'b'

/.*?b/
Capturing subpattern count = 0
No options
First char at start or follows \n
Need char = 'b'

/cat|dog|elephant/
Capturing subpattern count = 0
No options
No first char
No need char
    this sentence eventually mentions a cat
 0: cat
    this sentences rambles on and on for a while and then reaches elephant
 0: elephant

/cat|dog|elephant/S
Capturing subpattern count = 0
No options
No first char
No need char
Starting character set: c d e 
    this sentence eventually mentions a cat
 0: cat
    this sentences rambles on and on for a while and then reaches elephant
 0: elephant

/cat|dog|elephant/iS
Capturing subpattern count = 0
Options: caseless
No first char
No need char
Starting character set: C D E c d e 
    this sentence eventually mentions a CAT cat
 0: CAT
    this sentences rambles on and on for a while to elephant ElePhant
 0: elephant

/a|[bcd]/S
Capturing subpattern count = 0
No options
No first char
No need char
Starting character set: a b c d 

/(a|[^\dZ])/S
Capturing subpattern count = 1
No options
No first char
No need char
Starting character set: \x00 \x01 \x02 \x03 \x04 \x05 \x06 \x07 \x08 \x09 \x0a 
  \x0b \x0c \x0d \x0e \x0f \x10 \x11 \x12 \x13 \x14 \x15 \x16 \x17 \x18 \x19 
  \x1a \x1b \x1c \x1d \x1e \x1f \x20 ! " # $ % & ' ( ) * + , - . / : ; < = > 
  ? @ A B C D E F G H I J K L M N O P Q R S T U V W X Y [ \ ] ^ _ ` a b c d 
  e f g h i j k l m n o p q r s t u v w x y z { | } ~ \x7f \x80 \x81 \x82 \x83 
  \x84 \x85 \x86 \x87 \x88 \x89 \x8a \x8b \x8c \x8d \x8e \x8f \x90 \x91 \x92 
  \x93 \x94 \x95 \x96 \x97 \x98 \x99 \x9a \x9b \x9c \x9d \x9e \x9f \xa0 \xa1 
  \xa2 \xa3 \xa4 \xa5 \xa6 \xa7 \xa8 \xa9 \xaa \xab \xac \xad \xae \xaf \xb0 
  \xb1 \xb2 \xb3 \xb4 \xb5 \xb6 \xb7 \xb8 \xb9 \xba \xbb \xbc \xbd \xbe \xbf 
  \xc0 \xc1 \xc2 \xc3 \xc4 \xc5 \xc6 \xc7 \xc8 \xc9 \xca \xcb \xcc \xcd \xce 
  \xcf \xd0 \xd1 \xd2 \xd3 \xd4 \xd5 \xd6 \xd7 \xd8 \xd9 \xda \xdb \xdc \xdd 
  \xde \xdf \xe0 \xe1 \xe2 \xe3 \xe4 \xe5 \xe6 \xe7 \xe8 \xe9 \xea \xeb \xec 
  \xed \xee \xef \xf0 \xf1 \xf2 \xf3 \xf4 \xf5 \xf6 \xf7 \xf8 \xf9 \xfa \xfb 
  \xfc \xfd \xfe \xff 

/(a|b)*[\s]/S
Capturing subpattern count = 1
No options
No first char
No need char
Starting character set: \x09 \x0a \x0b \x0c \x0d \x20 a b 

/(ab\2)/
Failed: back reference to non-existent subpattern at offset 6

/{4,5}abc/
Failed: nothing to repeat at offset 4

/(a)(b)(c)\2/
Capturing subpattern count = 3
Max back reference = 2
No options
First char = 'a'
Need char = 'c'
    abcb
 0: abcb
 1: a
 2: b
 3: c
    \O0abcb
Matched, but too many substrings
    \O3abcb
Matched, but too many substrings
 0: abcb
    \O6abcb
Matched, but too many substrings
 0: abcb
 1: a
    \O9abcb
Matched, but too many substrings
 0: abcb
 1: a
 2: b
    \O12abcb 
 0: abcb
 1: a
 2: b
 3: c

/(a)bc|(a)(b)\2/
Capturing subpattern count = 3
Max back reference = 2
No options
First char = 'a'
No need char
    abc
 0: abc
 1: a
    \O0abc
Matched, but too many substrings
    \O3abc
Matched, but too many substrings
 0: abc
    \O6abc
 0: abc
 1: a
    aba
 0: aba
 1: <unset>
 2: a
 3: b
    \O0aba
Matched, but too many substrings
    \O3aba
Matched, but too many substrings
 0: aba
    \O6aba
Matched, but too many substrings
 0: aba
 1: <unset>
    \O9aba
Matched, but too many substrings
 0: aba
 1: <unset>
 2: a
    \O12aba
 0: aba
 1: <unset>
 2: a
 3: b

/abc$/E
Capturing subpattern count = 0
Options: dollar_endonly
First char = 'a'
Need char = 'c'
    abc
 0: abc
    *** Failers
No match
    abc\n
No match
    abc\ndef
No match

/(a)(b)(c)(d)(e)\6/
Failed: back reference to non-existent subpattern at offset 17

/the quick brown fox/
Capturing subpattern count = 0
No options
First char = 't'
Need char = 'x'
    the quick brown fox
 0: the quick brown fox
    this is a line with the quick brown fox
 0: the quick brown fox

/the quick brown fox/A
Capturing subpattern count = 0
Options: anchored
No first char
Need char = 'x'
    the quick brown fox
 0: the quick brown fox
    *** Failers
No match
    this is a line with the quick brown fox
No match

/ab(?z)cd/
Failed: unrecognized character after (? at offset 4

/^abc|def/
Capturing subpattern count = 0
No options
No first char
No need char
    abcdef
 0: abc
    abcdef\B
 0: def

/.*((abc)$|(def))/
Capturing subpattern count = 3
No options
First char at start or follows \n
No need char
    defabc
 0: defabc
 1: abc
 2: abc
    \Zdefabc
 0: def
 1: def
 2: <unset>
 3: def

/abc/P
    abc
 0: abc
    *** Failers
No match: POSIX code 17: match failed
    
/^abc|def/P
    abcdef
 0: abc
    abcdef\B
 0: def

/.*((abc)$|(def))/P
    defabc
 0: defabc
 1: abc
 2: abc
    \Zdefabc
 0: def
 1: def
 3: def
  
/the quick brown fox/P
    the quick brown fox
 0: the quick brown fox
    *** Failers 
No match: POSIX code 17: match failed
    The Quick Brown Fox 
No match: POSIX code 17: match failed

/the quick brown fox/Pi
    the quick brown fox
 0: the quick brown fox
    The Quick Brown Fox 
 0: The Quick Brown Fox

/abc.def/P
    *** Failers
No match: POSIX code 17: match failed
    abc\ndef
No match: POSIX code 17: match failed
    
/abc$/P
    abc
 0: abc
    abc\n 
 0: abc

/(abc)\2/P
Failed: POSIX code 15: bad back reference at offset 7     

/(abc\1)/P
    abc
No match: POSIX code 17: match failed

/)/
Failed: unmatched parentheses at offset 0

/a[]b/
Failed: missing terminating ] for character class at offset 4

/[^aeiou ]{3,}/
Capturing subpattern count = 0
No options
No first char
No need char
    co-processors, and for 
 0: -pr
    
/<.*>/
Capturing subpattern count = 0
No options
First char = '<'
Need char = '>'
    abc<def>ghi<klm>nop
 0: <def>ghi<klm>

/<.*?>/
Capturing subpattern count = 0
No options
First char = '<'
Need char = '>'
    abc<def>ghi<klm>nop
 0: <def>

/<.*>/U
Capturing subpattern count = 0
Options: ungreedy
First char = '<'
Need char = '>'
    abc<def>ghi<klm>nop
 0: <def>
    
/<.*>(?U)/
Capturing subpattern count = 0
Options: ungreedy
First char = '<'
Need char = '>'
    abc<def>ghi<klm>nop
 0: <def>

/<.*?>/U
Capturing subpattern count = 0
Options: ungreedy
First char = '<'
Need char = '>'
    abc<def>ghi<klm>nop
 0: <def>ghi<klm>
    
/={3,}/U
Capturing subpattern count = 0
Options: ungreedy
First char = '='
Need char = '='
    abc========def
 0: ===
    
/(?U)={3,}?/
Capturing subpattern count = 0
Options: ungreedy
First char = '='
Need char = '='
    abc========def
 0: ========
    
/(?<!bar|cattle)foo/
Capturing subpattern count = 0
No options
First char = 'f'
Need char = 'o'
    foo
 0: foo
    catfoo 
 0: foo
    *** Failers
No match
    the barfoo
No match
    and cattlefoo   
No match

/(?<=a+)b/
Failed: lookbehind assertion is not fixed length at offset 6

/(?<=aaa|b{0,3})b/
Failed: lookbehind assertion is not fixed length at offset 14

/(?<!(foo)a\1)bar/
Failed: lookbehind assertion is not fixed length at offset 12

/(?i)abc/
Capturing subpattern count = 0
Options: caseless
First char = 'a'
Need char = 'c'

/(a|(?m)a)/
Capturing subpattern count = 1
No options
First char = 'a'
No need char

/(?i)^1234/
Capturing subpattern count = 0
Options: anchored caseless
No first char
Need char = '4'

/(^b|(?i)^d)/
Capturing subpattern count = 1
Options: anchored
Case state changes
No first char
No need char

/(?s).*/
Capturing subpattern count = 0
Options: anchored dotall
No first char
No need char

/[abcd]/S
Capturing subpattern count = 0
No options
No first char
No need char
Starting character set: a b c d 

/(?i)[abcd]/S
Capturing subpattern count = 0
Options: caseless
No first char
No need char
Starting character set: A B C D a b c d 

/(?m)[xy]|(b|c)/S
Capturing subpattern count = 1
Options: multiline
No first char
No need char
Starting character set: b c x y 

/(^a|^b)/m
Capturing subpattern count = 1
Options: multiline
First char at start or follows \n
No need char

/(?i)(^a|^b)/m
Capturing subpattern count = 1
Options: caseless multiline
First char at start or follows \n
No need char

/(a)(?(1)a|b|c)/
Failed: conditional group contains more than two branches at offset 13

/(?(?=a)a|b|c)/
Failed: conditional group contains more than two branches at offset 12

/(?(1a)/
Failed: malformed number after (?( at offset 4

/(?(?i))/
Failed: assertion expected after (?( at offset 3

/(?(abc))/
Failed: assertion expected after (?( at offset 3

/(?(?<ab))/
Failed: unrecognized character after (?< at offset 2

/((?s)blah)\s+\1/
Capturing subpattern count = 1
Max back reference = 1
No options
First char = 'b'
Need char = 'h'

/((?i)blah)\s+\1/
Capturing subpattern count = 1
Max back reference = 1
No options
Case state changes
No first char
Need char = 'h'

/((?i)b)/DS
------------------------------------------------------------------
  0  16 Bra 0
  3   8 Bra 1
  6  01 Opt
  8   1 b
 11   8 Ket
 14  00 Opt
 16  16 Ket
 19     End
------------------------------------------------------------------
Capturing subpattern count = 1
No options
Case state changes
No first char
Need char = 'b'
Starting character set: B b 

/(a*b|(?i:c*(?-i)d))/S
Capturing subpattern count = 1
No options
Case state changes
No first char
No need char
Starting character set: C a b c d 

/a$/
Capturing subpattern count = 0
No options
First char = 'a'
No need char
    a
 0: a
    a\n
 0: a
    *** Failers 
No match
    \Za
No match
    \Za\n   
No match

/a$/m
Capturing subpattern count = 0
Options: multiline
First char = 'a'
No need char
    a
 0: a
    a\n
 0: a
    \Za\n   
 0: a
    *** Failers 
No match
    \Za
No match
    
/\Aabc/m
Capturing subpattern count = 0
Options: anchored multiline
No first char
Need char = 'c'

/^abc/m 
Capturing subpattern count = 0
Options: multiline
First char at start or follows \n
Need char = 'c'

/^((a+)(?U)([ab]+)(?-U)([bc]+)(\w*))/
Capturing subpattern count = 5
Options: anchored
No first char
Need char = 'a'
  aaaaabbbbbcccccdef
 0: aaaaabbbbbcccccdef
 1: aaaaabbbbbcccccdef
 2: aaaaa
 3: b
 4: bbbbccccc
 5: def

/(?<=foo)[ab]/S
Capturing subpattern count = 0
No options
No first char
No need char
Starting character set: a b 

/(?<!foo)(alpha|omega)/S
Capturing subpattern count = 1
No options
No first char
Need char = 'a'
Starting character set: a o 

/(?!alphabet)[ab]/S
Capturing subpattern count = 0
No options
No first char
No need char
Starting character set: a b 

/(?<=foo\n)^bar/m
Capturing subpattern count = 0
Options: multiline
First char at start or follows \n
Need char = 'r'

/(?>^abc)/m
Capturing subpattern count = 0
Options: multiline
First char at start or follows \n
Need char = 'c'
    abc
 0: abc
    def\nabc
 0: abc
    *** Failers
No match
    defabc   
No match

/(?<=ab(c+)d)ef/
Failed: lookbehind assertion is not fixed length at offset 11

/(?<=ab(?<=c+)d)ef/
Failed: lookbehind assertion is not fixed length at offset 12

/(?<=ab(c|de)f)g/
Failed: lookbehind assertion is not fixed length at offset 13

/The next three are in testinput2 because they have variable length branches/
Capturing subpattern count = 0
No options
First char = 'T'
Need char = 's'

/(?<=bullock|donkey)-cart/
Capturing subpattern count = 0
No options
First char = '-'
Need char = 't'
    the bullock-cart
 0: -cart
    a donkey-cart race
 0: -cart
    *** Failers
No match
    cart
No match
    horse-and-cart    
No match
      
/(?<=ab(?i)x|y|z)/
Capturing subpattern count = 0
No options
Case state changes
No first char
No need char

/(?>.*)(?<=(abcd)|(xyz))/
Capturing subpattern count = 2
No options
First char at start or follows \n
No need char
    alphabetabcd
 0: alphabetabcd
 1: abcd
    endingxyz
 0: endingxyz
 1: <unset>
 2: xyz

/(?<=ab(?i)x(?-i)y|(?i)z|b)ZZ/
Capturing subpattern count = 0
No options
Case state changes
First char = 'Z'
Need char = 'Z'
    abxyZZ
 0: ZZ
    abXyZZ
 0: ZZ
    ZZZ
 0: ZZ
    zZZ
 0: ZZ
    bZZ
 0: ZZ
    BZZ     
 0: ZZ
    *** Failers
No match
    ZZ 
No match
    abXYZZ 
No match
    zzz
No match
    bzz  
No match

/(?<!(foo)a)bar/
Capturing subpattern count = 1
No options
First char = 'b'
Need char = 'r'
    bar
 0: bar
    foobbar 
 0: bar
    *** Failers
No match
    fooabar  
No match

/This one is here because Perl 5.005_02 doesn't fail it/
Capturing subpattern count = 0
No options
First char = 'T'
Need char = 't'

/^(a)?(?(1)a|b)+$/
Capturing subpattern count = 1
Options: anchored
No first char
No need char
    *** Failers
No match
    a 
No match

/This one is here because I think Perl 5.005_02 gets the setting of $1 wrong/
Capturing subpattern count = 0
No options
First char = 'T'
Need char = 'g'

/^(a\1?){4}$/
Capturing subpattern count = 1
Max back reference = 1
Options: anchored
No first char
Need char = 'a'
    aaaaaa
 0: aaaaaa
 1: aa
    
/These are syntax tests from Perl 5.005/
Capturing subpattern count = 0
No options
First char = 'T'
Need char = '5'

/a[b-a]/
Failed: range out of order in character class at offset 4

/a[]b/
Failed: missing terminating ] for character class at offset 4

/a[/
Failed: missing terminating ] for character class at offset 2

/*a/
Failed: nothing to repeat at offset 0

/(*)b/
Failed: nothing to repeat at offset 1

/abc)/
Failed: unmatched parentheses at offset 3

/(abc/
Failed: missing ) at offset 4

/a**/
Failed: nothing to repeat at offset 2

/)(/
Failed: unmatched parentheses at offset 0

/\1/
Failed: back reference to non-existent subpattern at offset 2

/\2/
Failed: back reference to non-existent subpattern at offset 2

/(a)|\2/
Failed: back reference to non-existent subpattern at offset 6

/a[b-a]/i
Failed: range out of order in character class at offset 4

/a[]b/i
Failed: missing terminating ] for character class at offset 4

/a[/i
Failed: missing terminating ] for character class at offset 2

/*a/i
Failed: nothing to repeat at offset 0

/(*)b/i
Failed: nothing to repeat at offset 1

/abc)/i
Failed: unmatched parentheses at offset 3

/(abc/i
Failed: missing ) at offset 4

/a**/i
Failed: nothing to repeat at offset 2

/)(/i
Failed: unmatched parentheses at offset 0

/:(?:/
Failed: missing ) at offset 4

/(?<%)b/
Failed: unrecognized character after (?< at offset 0

/a(?{)b/
Failed: unrecognized character after (? at offset 3

/a(?{{})b/
Failed: unrecognized character after (? at offset 3

/a(?{}})b/
Failed: unrecognized character after (? at offset 3

/a(?{"{"})b/
Failed: unrecognized character after (? at offset 3

/a(?{"{"}})b/
Failed: unrecognized character after (? at offset 3

/(?(1?)a|b)/
Failed: malformed number after (?( at offset 4

/(?(1)a|b|c)/
Failed: conditional group contains more than two branches at offset 10

/[a[:xyz:/
Failed: missing terminating ] for character class at offset 8

/(?<=x+)y/
Failed: lookbehind assertion is not fixed length at offset 6

/a{37,17}/
Failed: numbers out of order in {} quantifier at offset 7

/abc/\
Failed: \ at end of pattern at offset 4

/abc/\P
Failed: POSIX code 9: bad escape sequence at offset 4     

/abc/\i
Failed: \ at end of pattern at offset 4

/(a)bc(d)/
Capturing subpattern count = 2
No options
First char = 'a'
Need char = 'd'
    abcd
 0: abcd
 1: a
 2: d
    abcd\C2
 0: abcd
 1: a
 2: d
 2C d (1)
    abcd\C5
 0: abcd
 1: a
 2: d
copy substring 5 failed -7
     
/(.{20})/
Capturing subpattern count = 1
No options
No first char
No need char
    abcdefghijklmnopqrstuvwxyz
 0: abcdefghijklmnopqrst
 1: abcdefghijklmnopqrst
    abcdefghijklmnopqrstuvwxyz\C1
 0: abcdefghijklmnopqrst
 1: abcdefghijklmnopqrst
copy substring 1 failed -6
    abcdefghijklmnopqrstuvwxyz\G1
 0: abcdefghijklmnopqrst
 1: abcdefghijklmnopqrst
 1G abcdefghijklmnopqrst (20)
     
/(.{15})/
Capturing subpattern count = 1
No options
No first char
No need char
    abcdefghijklmnopqrstuvwxyz
 0: abcdefghijklmno
 1: abcdefghijklmno
    abcdefghijklmnopqrstuvwxyz\C1\G1
 0: abcdefghijklmno
 1: abcdefghijklmno
 1C abcdefghijklmno (15)
 1G abcdefghijklmno (15)

/(.{16})/
Capturing subpattern count = 1
No options
No first char
No need char
    abcdefghijklmnopqrstuvwxyz
 0: abcdefghijklmnop
 1: abcdefghijklmnop
    abcdefghijklmnopqrstuvwxyz\C1\G1\L
 0: abcdefghijklmnop
 1: abcdefghijklmnop
copy substring 1 failed -6
 1G abcdefghijklmnop (16)
 0L abcdefghijklmnop
 1L abcdefghijklmnop
    
/^(a|(bc))de(f)/
Capturing subpattern count = 3
Options: anchored
No first char
Need char = 'f'
    adef\G1\G2\G3\G4\L 
 0: adef
 1: a
 2: <unset>
 3: f
 1G a (1)
 2G  (0)
 3G f (1)
get substring 4 failed -7
 0L adef
 1L a
 2L 
 3L f
    bcdef\G1\G2\G3\G4\L 
 0: bcdef
 1: bc
 2: bc
 3: f
 1G bc (2)
 2G bc (2)
 3G f (1)
get substring 4 failed -7
 0L bcdef
 1L bc
 2L bc
 3L f
    adefghijk\C0 
 0: adef
 1: a
 2: <unset>
 3: f
 0C adef (4)
    
/^abc\00def/
Capturing subpattern count = 0
Options: anchored
No first char
Need char = 'f'
    abc\00def\L\C0 
 0: abc\x00def
 0C abc (7)
 0L abc
    
/word ((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ 
)((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ 
)?)?)?)?)?)?)?)?)?otherword/M
Memory allocation (code space): 428
Capturing subpattern count = 8
No options
First char = 'w'
Need char = 'd'

/.*X/D
------------------------------------------------------------------
  0   8 Bra 0
  3     Any*
  5   1 X
  8   8 Ket
 11     End
------------------------------------------------------------------
Capturing subpattern count = 0
No options
First char at start or follows \n
Need char = 'X'

/.*X/Ds
------------------------------------------------------------------
  0   8 Bra 0
  3     Any*
  5   1 X
  8   8 Ket
 11     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored dotall
No first char
Need char = 'X'

/(.*X|^B)/D
------------------------------------------------------------------
  0  21 Bra 0
  3   8 Bra 1
  6     Any*
  8   1 X
 11   7 Alt
 14     ^
 15   1 B
 18  15 Ket
 21  21 Ket
 24     End
------------------------------------------------------------------
Capturing subpattern count = 1
No options
First char at start or follows \n
No need char

/(.*X|^B)/Ds
------------------------------------------------------------------
  0  21 Bra 0
  3   8 Bra 1
  6     Any*
  8   1 X
 11   7 Alt
 14     ^
 15   1 B
 18  15 Ket
 21  21 Ket
 24     End
------------------------------------------------------------------
Capturing subpattern count = 1
Options: anchored dotall
No first char
No need char
    
/(?s)(.*X|^B)/D
------------------------------------------------------------------
  0  21 Bra 0
  3   8 Bra 1
  6     Any*
  8   1 X
 11   7 Alt
 14     ^
 15   1 B
 18  15 Ket
 21  21 Ket
 24     End
------------------------------------------------------------------
Capturing subpattern count = 1
Options: anchored dotall
No first char
No need char

/(?s:.*X|^B)/D
------------------------------------------------------------------
  0  27 Bra 0
  3  10 Bra 0
  6  04 Opt
  8     Any*
 10   1 X
 13   9 Alt
 16  04 Opt
 18     ^
 19   1 B
 22  19 Ket
 25  00 Opt
 27  27 Ket
 30     End
------------------------------------------------------------------
Capturing subpattern count = 0
No options
First char at start or follows \n
No need char

/\Biss\B/+
Capturing subpattern count = 0
No options
First char = 'i'
Need char = 's'
    Mississippi
 0: iss
 0+ issippi

/\Biss\B/+P
    Mississippi
 0: iss
 0+ issippi

/iss/G+
Capturing subpattern count = 0
No options
First char = 'i'
Need char = 's'
    Mississippi
 0: iss
 0+ issippi
 0: iss
 0+ ippi

/\Biss\B/G+
Capturing subpattern count = 0
No options
First char = 'i'
Need char = 's'
    Mississippi
 0: iss
 0+ issippi

/\Biss\B/g+
Capturing subpattern count = 0
No options
First char = 'i'
Need char = 's'
    Mississippi
 0: iss
 0+ issippi
 0: iss
 0+ ippi
    *** Failers
No match
    Mississippi\A
No match

/(?<=[Ms])iss/g+
Capturing subpattern count = 0
No options
First char = 'i'
Need char = 's'
    Mississippi
 0: iss
 0+ issippi
 0: iss
 0+ ippi

/(?<=[Ms])iss/G+
Capturing subpattern count = 0
No options
First char = 'i'
Need char = 's'
    Mississippi
 0: iss
 0+ issippi

/^iss/g+
Capturing subpattern count = 0
Options: anchored
No first char
Need char = 's'
    ississippi
 0: iss
 0+ issippi
    
/.*iss/g+
Capturing subpattern count = 0
No options
First char at start or follows \n
Need char = 's'
    abciss\nxyzisspqr 
 0: abciss
 0+ \x0axyzisspqr
 0: xyziss
 0+ pqr

/.i./+g
Capturing subpattern count = 0
No options
No first char
Need char = 'i'
    Mississippi
 0: Mis
 0+ sissippi
 0: sis
 0+ sippi
 0: sip
 0+ pi
    Mississippi\A
 0: Mis
 0+ sissippi
 0: sis
 0+ sippi
 0: sip
 0+ pi
    Missouri river
 0: Mis
 0+ souri river
 0: ri 
 0+ river
 0: riv
 0+ er
    Missouri river\A  
 0: Mis
 0+ souri river

/^.is/+g
Capturing subpattern count = 0
Options: anchored
No first char
Need char = 's'
    Mississippi
 0: Mis
 0+ sissippi

/^ab\n/g+
Capturing subpattern count = 0
Options: anchored
No first char
Need char = 10
    ab\nab\ncd
 0: ab\x0a
 0+ ab\x0acd

/^ab\n/mg+
Capturing subpattern count = 0
Options: multiline
First char at start or follows \n
Need char = 10
    ab\nab\ncd
 0: ab\x0a
 0+ ab\x0acd
 0: ab\x0a
 0+ cd

/abc/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'c'

/abc|bac/
Capturing subpattern count = 0
No options
No first char
Need char = 'c'

/(abc|bac)/
Capturing subpattern count = 1
No options
No first char
Need char = 'c'

/(abc|(c|dc))/
Capturing subpattern count = 2
No options
No first char
Need char = 'c'

/(abc|(d|de)c)/
Capturing subpattern count = 2
No options
No first char
Need char = 'c'

/a*/
Capturing subpattern count = 0
No options
No first char
No need char

/a+/
Capturing subpattern count = 0
No options
First char = 'a'
No need char

/(baa|a+)/
Capturing subpattern count = 1
No options
No first char
Need char = 'a'

/a{0,3}/
Capturing subpattern count = 0
No options
No first char
No need char

/baa{3,}/
Capturing subpattern count = 0
No options
First char = 'b'
Need char = 'a'

/"([^\\"]+|\\.)*"/
Capturing subpattern count = 1
No options
First char = '"'
Need char = '"'

/(abc|ab[cd])/
Capturing subpattern count = 1
No options
First char = 'a'
No need char

/(a|.)/
Capturing subpattern count = 1
No options
No first char
No need char

/a|ba|\w/
Capturing subpattern count = 0
No options
No first char
No need char

/abc(?=pqr)/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'r'

/...(?<=abc)/
Capturing subpattern count = 0
No options
No first char
No need char

/abc(?!pqr)/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'c'

/ab./
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'b'

/ab[xyz]/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'b'

/abc*/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'b'

/ab.c*/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'b'

/a.c*/
Capturing subpattern count = 0
No options
First char = 'a'
No need char

/.c*/
Capturing subpattern count = 0
No options
No first char
No need char

/ac*/
Capturing subpattern count = 0
No options
First char = 'a'
No need char

/(a.c*|b.c*)/
Capturing subpattern count = 1
No options
No first char
No need char

/a.c*|aba/
Capturing subpattern count = 0
No options
First char = 'a'
No need char

/.+a/
Capturing subpattern count = 0
No options
No first char
Need char = 'a'

/(?=abcda)a.*/
Capturing subpattern count = 0
No options
First char = 'a'
No need char

/(?=a)a.*/
Capturing subpattern count = 0
No options
First char = 'a'
No need char

/a(b)*/
Capturing subpattern count = 1
No options
First char = 'a'
No need char

/a\d*/
Capturing subpattern count = 0
No options
First char = 'a'
No need char

/ab\d*/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'b'

/a(\d)*/
Capturing subpattern count = 1
No options
First char = 'a'
No need char

/abcde{0,0}/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'd'

/ab\d+/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'b'

/a(?(1)b)/
Capturing subpattern count = 0
No options
First char = 'a'
No need char

/a(?(1)bag|big)/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'g'

/a(?(1)bag|big)*/
Capturing subpattern count = 0
No options
First char = 'a'
No need char

/a(?(1)bag|big)+/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'g'

/a(?(1)b..|b..)/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'b'

/ab\d{0}e/
Capturing subpattern count = 0
No options
First char = 'a'
Need char = 'e'

/a?b?/
Capturing subpattern count = 0
No options
No first char
No need char
    a
 0: a
    b
 0: b
    ab
 0: ab
    \
 0: 
    *** Failers
 0: 
    \N     
No match
    
/|-/
Capturing subpattern count = 0
No options
No first char
No need char
    abcd
 0: 
    -abc
 0: 
    \Nab-c
 0: -
    *** Failers
 0: 
    \Nabc     
No match

/a*(b+)(z)(z)/P
    aaaabbbbzzzz
 0: aaaabbbbzz
 1: bbbb
 2: z
 3: z
    aaaabbbbzzzz\O0
    aaaabbbbzzzz\O1
 0: aaaabbbbzz
    aaaabbbbzzzz\O2
 0: aaaabbbbzz
 1: bbbb
    aaaabbbbzzzz\O3
 0: aaaabbbbzz
 1: bbbb
 2: z
    aaaabbbbzzzz\O4
 0: aaaabbbbzz
 1: bbbb
 2: z
 3: z
    aaaabbbbzzzz\O5
 0: aaaabbbbzz
 1: bbbb
 2: z
 3: z
    
/^.?abcd/S 
Capturing subpattern count = 0
Options: anchored
No first char
Need char = 'd'
Study returned NULL

/\(             # ( at start
  (?:           # Non-capturing bracket
  (?>[^()]+)    # Either a sequence of non-brackets (no backtracking)
  |             # Or
  (?R)          # Recurse - i.e. nested bracketed string
  )*            # Zero or more contents
  \)            # Closing )
  /x
Capturing subpattern count = 0
Options: extended
First char = '('
Need char = ')'
    (abcd)
 0: (abcd)
    (abcd)xyz
 0: (abcd)
    xyz(abcd)
 0: (abcd)
    (ab(xy)cd)pqr 
 0: (ab(xy)cd)
    (ab(xycd)pqr 
 0: (xycd)
    () abc () 
 0: ()
    12(abcde(fsh)xyz(foo(bar))lmno)89
 0: (abcde(fsh)xyz(foo(bar))lmno)
    *** Failers
No match
    abcd 
No match
    abcd)
No match
    (abcd  
No match

/\(  ( (?>[^()]+) | (?R) )* \) /xg
Capturing subpattern count = 1
Options: extended
First char = '('
Need char = ')'
    (ab(xy)cd)pqr 
 0: (ab(xy)cd)
 1: cd
    1(abcd)(x(y)z)pqr
 0: (abcd)
 1: abcd
 0: (x(y)z)
 1: z

/\(  (?: (?>[^()]+) | (?R) ) \) /x
Capturing subpattern count = 0
Options: extended
First char = '('
Need char = ')'
    (abcd)
 0: (abcd)
    (ab(xy)cd)
 0: (xy)
    (a(b(c)d)e) 
 0: (c)
    ((ab)) 
 0: ((ab))
    *** Failers
No match
    ()   
No match

/\(  (?: (?>[^()]+) | (?R) )? \) /x
Capturing subpattern count = 0
Options: extended
First char = '('
Need char = ')'
    ()
 0: ()
    12(abcde(fsh)xyz(foo(bar))lmno)89
 0: (fsh)

/\(  ( (?>[^()]+) | (?R) )* \) /x
Capturing subpattern count = 1
Options: extended
First char = '('
Need char = ')'
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: cd

/\( ( ( (?>[^()]+) | (?R) )* ) \) /x
Capturing subpattern count = 2
Options: extended
First char = '('
Need char = ')'
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: ab(xy)cd
 2: cd

/\( (123)? ( ( (?>[^()]+) | (?R) )* ) \) /x
Capturing subpattern count = 3
Options: extended
First char = '('
Need char = ')'
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: <unset>
 2: ab(xy)cd
 3: cd
    (123ab(xy)cd)
 0: (123ab(xy)cd)
 1: 123
 2: ab(xy)cd
 3: cd

/\( ( (123)? ( (?>[^()]+) | (?R) )* ) \) /x
Capturing subpattern count = 3
Options: extended
First char = '('
Need char = ')'
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: ab(xy)cd
 2: <unset>
 3: cd
    (123ab(xy)cd)
 0: (123ab(xy)cd)
 1: 123ab(xy)cd
 2: 123
 3: cd

/\( (((((((((( ( (?>[^()]+) | (?R) )* )))))))))) \) /x
Capturing subpattern count = 11
Options: extended
First char = '('
Need char = ')'
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: ab(xy)cd
 2: ab(xy)cd
 3: ab(xy)cd
 4: ab(xy)cd
 5: ab(xy)cd
 6: ab(xy)cd
 7: ab(xy)cd
 8: ab(xy)cd
 9: ab(xy)cd
10: ab(xy)cd
11: cd

/\( ( ( (?>[^()<>]+) | ((?>[^()]+)) | (?R) )* ) \) /x
Capturing subpattern count = 3
Options: extended
First char = '('
Need char = ')'
    (abcd(xyz<p>qrs)123)
 0: (abcd(xyz<p>qrs)123)
 1: abcd(xyz<p>qrs)123
 2: 123
 3: <p>qrs

/\( ( ( (?>[^()]+) | ((?R)) )* ) \) /x
Capturing subpattern count = 3
Options: extended
First char = '('
Need char = ')'
    (ab(cd)ef)
 0: (ab(cd)ef)
 1: ab(cd)ef
 2: ef
 3: (cd)
    (ab(cd(ef)gh)ij)
 0: (ab(cd(ef)gh)ij)
 1: ab(cd(ef)gh)ij
 2: ij
 3: (cd(ef)gh)

/^[[:alnum:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [0-9A-Za-z]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[[:alpha:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [A-Za-z]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char
             
/^[[:ascii:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [\x00-\x7f]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[[:cntrl:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [\x00-\x1f\x7f]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[[:digit:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [0-9]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[[:graph:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [!-~]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[[:lower:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [a-z]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[[:print:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [ -~]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[[:punct:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [!-/:-@[-`{-~]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[[:space:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [\x09-\x0d ]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[[:upper:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [A-Z]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[[:xdigit:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [0-9A-Fa-f]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[[:word:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [0-9A-Z_a-z]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[[:^cntrl:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [ -~\x80-\xff]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/^[12[:^digit:]]/D
------------------------------------------------------------------
  0  37 Bra 0
  3     ^
  4     [\x00-/1-2:-\xff]
 37  37 Ket
 40     End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: anchored
No first char
No need char

/[01[:alpha:]%]/D
------------------------------------------------------------------
  0  36 Bra 0
  3     [%0-1A-Za-z]
 36  36 Ket
 39     End
------------------------------------------------------------------
Capturing subpattern count = 0
No options
No first char
No need char

/[[.ch.]]/
Failed: POSIX collating elements are not supported at offset 1

/[[=ch=]]/
Failed: POSIX collating elements are not supported at offset 1

/[[:rhubarb:]]/
Failed: unknown POSIX class name at offset 3

/[[:upper:]]/i
Capturing subpattern count = 0
Options: caseless
No first char
No need char
    A
 0: A
    a 
 0: a
    
/[[:lower:]]/i
Capturing subpattern count = 0
Options: caseless
No first char
No need char
    A
 0: A
    a 
 0: a

/((?-i)[[:lower:]])[[:lower:]]/i
Capturing subpattern count = 1
Options: caseless
Case state changes
No first char
No need char
    ab
 0: ab
 1: a
    aB
 0: aB
 1: a
    *** Failers
 0: ai
 1: a
    Ab
No match
    AB        
No match

/[\200-\410]/
Failed: range out of order in character class at offset 9

/^(?(0)f|b)oo/
Failed: invalid condition (?(0) at offset 5

/This one's here because of the large output vector needed/
Capturing subpattern count = 0
No options
First char = 'T'
Need char = 'd'

/(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\w+)\s+(\270)/
Capturing subpattern count = 271
Max back reference = 270
No options
No first char
No need char
    \O900 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 ABC ABC
 0: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 ABC ABC
 1: 1 
 2: 2 
 3: 3 
 4: 4 
 5: 5 
 6: 6 
 7: 7 
 8: 8 
 9: 9 
10: 10 
11: 11 
12: 12 
13: 13 
14: 14 
15: 15 
16: 16 
17: 17 
18: 18 
19: 19 
20: 20 
21: 21 
22: 22 
23: 23 
24: 24 
25: 25 
26: 26 
27: 27 
28: 28 
29: 29 
30: 30 
31: 31 
32: 32 
33: 33 
34: 34 
35: 35 
36: 36 
37: 37 
38: 38 
39: 39 
40: 40 
41: 41 
42: 42 
43: 43 
44: 44 
45: 45 
46: 46 
47: 47 
48: 48 
49: 49 
50: 50 
51: 51 
52: 52 
53: 53 
54: 54 
55: 55 
56: 56 
57: 57 
58: 58 
59: 59 
60: 60 
61: 61 
62: 62 
63: 63 
64: 64 
65: 65 
66: 66 
67: 67 
68: 68 
69: 69 
70: 70 
71: 71 
72: 72 
73: 73 
74: 74 
75: 75 
76: 76 
77: 77 
78: 78 
79: 79 
80: 80 
81: 81 
82: 82 
83: 83 
84: 84 
85: 85 
86: 86 
87: 87 
88: 88 
89: 89 
90: 90 
91: 91 
92: 92 
93: 93 
94: 94 
95: 95 
96: 96 
97: 97 
98: 98 
99: 99 
100: 100 
101: 101 
102: 102 
103: 103 
104: 104 
105: 105 
106: 106 
107: 107 
108: 108 
109: 109 
110: 110 
111: 111 
112: 112 
113: 113 
114: 114 
115: 115 
116: 116 
117: 117 
118: 118 
119: 119 
120: 120 
121: 121 
122: 122 
123: 123 
124: 124 
125: 125 
126: 126 
127: 127 
128: 128 
129: 129 
130: 130 
131: 131 
132: 132 
133: 133 
134: 134 
135: 135 
136: 136 
137: 137 
138: 138 
139: 139 
140: 140 
141: 141 
142: 142 
143: 143 
144: 144 
145: 145 
146: 146 
147: 147 
148: 148 
149: 149 
150: 150 
151: 151 
152: 152 
153: 153 
154: 154 
155: 155 
156: 156 
157: 157 
158: 158 
159: 159 
160: 160 
161: 161 
162: 162 
163: 163 
164: 164 
165: 165 
166: 166 
167: 167 
168: 168 
169: 169 
170: 170 
171: 171 
172: 172 
173: 173 
174: 174 
175: 175 
176: 176 
177: 177 
178: 178 
179: 179 
180: 180 
181: 181 
182: 182 
183: 183 
184: 184 
185: 185 
186: 186 
187: 187 
188: 188 
189: 189 
190: 190 
191: 191 
192: 192 
193: 193 
194: 194 
195: 195 
196: 196 
197: 197 
198: 198 
199: 199 
200: 200 
201: 201 
202: 202 
203: 203 
204: 204 
205: 205 
206: 206 
207: 207 
208: 208 
209: 209 
210: 210 
211: 211 
212: 212 
213: 213 
214: 214 
215: 215 
216: 216 
217: 217 
218: 218 
219: 219 
220: 220 
221: 221 
222: 222 
223: 223 
224: 224 
225: 225 
226: 226 
227: 227 
228: 228 
229: 229 
230: 230 
231: 231 
232: 232 
233: 233 
234: 234 
235: 235 
236: 236 
237: 237 
238: 238 
239: 239 
240: 240 
241: 241 
242: 242 
243: 243 
244: 244 
245: 245 
246: 246 
247: 247 
248: 248 
249: 249 
250: 250 
251: 251 
252: 252 
253: 253 
254: 254 
255: 255 
256: 256 
257: 257 
258: 258 
259: 259 
260: 260 
261: 261 
262: 262 
263: 263 
264: 264 
265: 265 
266: 266 
267: 267 
268: 268 
269: 269 
270: ABC
271: ABC

/This one's here because Perl does this differently and PCRE can't at present/
Capturing subpattern count = 0
No options
First char = 'T'
Need char = 't'

/(main(O)?)+/
Capturing subpattern count = 2
No options
First char = 'm'
Need char = 'n'
    mainmain
 0: mainmain
 1: main
    mainOmain
 0: mainOmain
 1: main
 2: O
    
/ End of testinput2 /
Capturing subpattern count = 0
No options
First char = ' '
Need char = ' '

