testoutput1

# This set of tests is for features that are compatible with all versions of
# Perl >= 5.10, in non-UTF mode. It should run clean for the 8-bit, 16-bit, and
# 32-bit PCRE libraries, and also using the perltest.pl script.
    
#forbid_utf
#newline_default lf any anycrlf
#perltest

/the quick brown fox/
    the quick brown fox
 0: the quick brown fox
    What do you know about the quick brown fox?
 0: the quick brown fox
\= Expect no match
    The quick brown FOX
No match
    What do you know about THE QUICK BROWN FOX?
No match

/The quick brown fox/i
    the quick brown fox
 0: the quick brown fox
    The quick brown FOX
 0: The quick brown FOX
    What do you know about the quick brown fox?
 0: the quick brown fox
    What do you know about THE QUICK BROWN FOX?
 0: THE QUICK BROWN FOX

/abcd\t\n\r\f\a\e\071\x3b\$\\\?caxyz/
    abcd\t\n\r\f\a\e9;\$\\?caxyz
 0: abcd\x09\x0a\x0d\x0c\x07\x1b9;$\?caxyz

/a*abc?xyz+pqr{3}ab{2,}xy{4,5}pq{0,6}AB{0,}zz/
    abxyzpqrrrabbxyyyypqAzz
 0: abxyzpqrrrabbxyyyypqAzz
    abxyzpqrrrabbxyyyypqAzz
 0: abxyzpqrrrabbxyyyypqAzz
    aabxyzpqrrrabbxyyyypqAzz
 0: aabxyzpqrrrabbxyyyypqAzz
    aaabxyzpqrrrabbxyyyypqAzz
 0: aaabxyzpqrrrabbxyyyypqAzz
    aaaabxyzpqrrrabbxyyyypqAzz
 0: aaaabxyzpqrrrabbxyyyypqAzz
    abcxyzpqrrrabbxyyyypqAzz
 0: abcxyzpqrrrabbxyyyypqAzz
    aabcxyzpqrrrabbxyyyypqAzz
 0: aabcxyzpqrrrabbxyyyypqAzz
    aaabcxyzpqrrrabbxyyyypAzz
 0: aaabcxyzpqrrrabbxyyyypAzz
    aaabcxyzpqrrrabbxyyyypqAzz
 0: aaabcxyzpqrrrabbxyyyypqAzz
    aaabcxyzpqrrrabbxyyyypqqAzz
 0: aaabcxyzpqrrrabbxyyyypqqAzz
    aaabcxyzpqrrrabbxyyyypqqqAzz
 0: aaabcxyzpqrrrabbxyyyypqqqAzz
    aaabcxyzpqrrrabbxyyyypqqqqAzz
 0: aaabcxyzpqrrrabbxyyyypqqqqAzz
    aaabcxyzpqrrrabbxyyyypqqqqqAzz
 0: aaabcxyzpqrrrabbxyyyypqqqqqAzz
    aaabcxyzpqrrrabbxyyyypqqqqqqAzz
 0: aaabcxyzpqrrrabbxyyyypqqqqqqAzz
    aaaabcxyzpqrrrabbxyyyypqAzz
 0: aaaabcxyzpqrrrabbxyyyypqAzz
    abxyzzpqrrrabbxyyyypqAzz
 0: abxyzzpqrrrabbxyyyypqAzz
    aabxyzzzpqrrrabbxyyyypqAzz
 0: aabxyzzzpqrrrabbxyyyypqAzz
    aaabxyzzzzpqrrrabbxyyyypqAzz
 0: aaabxyzzzzpqrrrabbxyyyypqAzz
    aaaabxyzzzzpqrrrabbxyyyypqAzz
 0: aaaabxyzzzzpqrrrabbxyyyypqAzz
    abcxyzzpqrrrabbxyyyypqAzz
 0: abcxyzzpqrrrabbxyyyypqAzz
    aabcxyzzzpqrrrabbxyyyypqAzz
 0: aabcxyzzzpqrrrabbxyyyypqAzz
    aaabcxyzzzzpqrrrabbxyyyypqAzz
 0: aaabcxyzzzzpqrrrabbxyyyypqAzz
    aaaabcxyzzzzpqrrrabbxyyyypqAzz
 0: aaaabcxyzzzzpqrrrabbxyyyypqAzz
    aaaabcxyzzzzpqrrrabbbxyyyypqAzz
 0: aaaabcxyzzzzpqrrrabbbxyyyypqAzz
    aaaabcxyzzzzpqrrrabbbxyyyyypqAzz
 0: aaaabcxyzzzzpqrrrabbbxyyyyypqAzz
    aaabcxyzpqrrrabbxyyyypABzz
 0: aaabcxyzpqrrrabbxyyyypABzz
    aaabcxyzpqrrrabbxyyyypABBzz
 0: aaabcxyzpqrrrabbxyyyypABBzz
    >>>aaabxyzpqrrrabbxyyyypqAzz
 0: aaabxyzpqrrrabbxyyyypqAzz
    >aaaabxyzpqrrrabbxyyyypqAzz
 0: aaaabxyzpqrrrabbxyyyypqAzz
    >>>>abcxyzpqrrrabbxyyyypqAzz
 0: abcxyzpqrrrabbxyyyypqAzz
\= Expect no match
    abxyzpqrrabbxyyyypqAzz
No match
    abxyzpqrrrrabbxyyyypqAzz
No match
    abxyzpqrrrabxyyyypqAzz
No match
    aaaabcxyzzzzpqrrrabbbxyyyyyypqAzz
No match
    aaaabcxyzzzzpqrrrabbbxyyypqAzz
No match
    aaabcxyzpqrrrabbxyyyypqqqqqqqAzz
No match

/^(abc){1,2}zz/
    abczz
 0: abczz
 1: abc
    abcabczz
 0: abcabczz
 1: abc
\= Expect no match
    zz
No match
    abcabcabczz
No match
    >>abczz
No match

/^(b+?|a){1,2}?c/
    bc
 0: bc
 1: b
    bbc
 0: bbc
 1: b
    bbbc
 0: bbbc
 1: bb
    bac
 0: bac
 1: a
    bbac
 0: bbac
 1: a
    aac
 0: aac
 1: a
    abbbbbbbbbbbc
 0: abbbbbbbbbbbc
 1: bbbbbbbbbbb
    bbbbbbbbbbbac
 0: bbbbbbbbbbbac
 1: a
\= Expect no match
    aaac
No match
    abbbbbbbbbbbac
No match

/^(b+|a){1,2}c/
    bc
 0: bc
 1: b
    bbc
 0: bbc
 1: bb
    bbbc
 0: bbbc
 1: bbb
    bac
 0: bac
 1: a
    bbac
 0: bbac
 1: a
    aac
 0: aac
 1: a
    abbbbbbbbbbbc
 0: abbbbbbbbbbbc
 1: bbbbbbbbbbb
    bbbbbbbbbbbac
 0: bbbbbbbbbbbac
 1: a
\= Expect no match
    aaac
No match
    abbbbbbbbbbbac
No match

/^(b+|a){1,2}?bc/
    bbc
 0: bbc
 1: b

/^(b*|ba){1,2}?bc/
    babc
 0: babc
 1: ba
    bbabc
 0: bbabc
 1: ba
    bababc
 0: bababc
 1: ba
\= Expect no match
    bababbc
No match
    babababc
No match

/^(ba|b*){1,2}?bc/
    babc
 0: babc
 1: ba
    bbabc
 0: bbabc
 1: ba
    bababc
 0: bababc
 1: ba
\= Expect no match
    bababbc
No match
    babababc
No match

#/^\ca\cA\c[;\c:/
#    \x01\x01\e;z
# 0: \x01\x01\x1b;z

/^[ab\]cde]/
    athing
 0: a
    bthing
 0: b
    ]thing
 0: ]
    cthing
 0: c
    dthing
 0: d
    ething
 0: e
\= Expect no match
    fthing
No match
    [thing
No match
    \\thing
No match

/^[]cde]/
    ]thing
 0: ]
    cthing
 0: c
    dthing
 0: d
    ething
 0: e
\= Expect no match
    athing
No match
    fthing
No match

/^[^ab\]cde]/
    fthing
 0: f
    [thing
 0: [
    \\thing
 0: \
\= Expect no match
    athing
No match
    bthing
No match
    ]thing
No match
    cthing
No match
    dthing
No match
    ething
No match

/^[^]cde]/
    athing
 0: a
    fthing
 0: f
\= Expect no match
    ]thing
No match
    cthing
No match
    dthing
No match
    ething
No match

# DLC - I don't get this one
#/^\/
#    
# 0: \x81

#updated to handle 16-bits utf8
/^ÿ/
    ÿ
 0: \xc3\xbf

/^[0-9]+$/
    0
 0: 0
    1
 0: 1
    2
 0: 2
    3
 0: 3
    4
 0: 4
    5
 0: 5
    6
 0: 6
    7
 0: 7
    8
 0: 8
    9
 0: 9
    10
 0: 10
    100
 0: 100
\= Expect no match
    abc
No match

/^.*nter/
    enter
 0: enter
    inter
 0: inter
    uponter
 0: uponter

/^xxx[0-9]+$/
    xxx0
 0: xxx0
    xxx1234
 0: xxx1234
\= Expect no match
    xxx
No match

/^.+[0-9][0-9][0-9]$/
    x123
 0: x123
    x1234
 0: x1234
    xx123
 0: xx123
    123456
 0: 123456
\= Expect no match
    123
No match

/^.+?[0-9][0-9][0-9]$/
    x123
 0: x123
    x1234
 0: x1234
    xx123
 0: xx123
    123456
 0: 123456
\= Expect no match
    123
No match

/^([^!]+)!(.+)=apquxz\.ixr\.zzz\.ac\.uk$/
    abc!pqr=apquxz.ixr.zzz.ac.uk
 0: abc!pqr=apquxz.ixr.zzz.ac.uk
 1: abc
 2: pqr
\= Expect no match
    !pqr=apquxz.ixr.zzz.ac.uk
No match
    abc!=apquxz.ixr.zzz.ac.uk
No match
    abc!pqr=apquxz:ixr.zzz.ac.uk
No match
    abc!pqr=apquxz.ixr.zzz.ac.ukk
No match

/:/
    Well, we need a colon: somewhere
 0: :
\= Expect no match
    Fail without a colon
No match

/([\da-f:]+)$/i
    0abc
 0: 0abc
 1: 0abc
    abc
 0: abc
 1: abc
    fed
 0: fed
 1: fed
    E
 0: E
 1: E
    ::
 0: ::
 1: ::
    5f03:12C0::932e
 0: 5f03:12C0::932e
 1: 5f03:12C0::932e
    fed def
 0: def
 1: def
    Any old stuff
 0: ff
 1: ff
\= Expect no match
    0zzz
No match
    gzzz
No match
    fed\x20
No match
    Any old rubbish
No match

/^.*\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/
    .1.2.3
 0: .1.2.3
 1: 1
 2: 2
 3: 3
    A.12.123.0
 0: A.12.123.0
 1: 12
 2: 123
 3: 0
\= Expect no match
    .1.2.3333
No match
    1.2.3
No match
    1234.2.3
No match

/^(\d+)\s+IN\s+SOA\s+(\S+)\s+(\S+)\s*\(\s*$/
    1 IN SOA non-sp1 non-sp2(
 0: 1 IN SOA non-sp1 non-sp2(
 1: 1
 2: non-sp1
 3: non-sp2
    1    IN    SOA    non-sp1    non-sp2   (
 0: 1    IN    SOA    non-sp1    non-sp2   (
 1: 1
 2: non-sp1
 3: non-sp2
\= Expect no match
    1IN SOA non-sp1 non-sp2(
No match

/^[a-zA-Z\d][a-zA-Z\d\-]*(\.[a-zA-Z\d][a-zA-z\d\-]*)*\.$/
    a.
 0: a.
    Z.
 0: Z.
    2.
 0: 2.
    ab-c.pq-r.
 0: ab-c.pq-r.
 1: .pq-r
    sxk.zzz.ac.uk.
 0: sxk.zzz.ac.uk.
 1: .uk
    x-.y-.
 0: x-.y-.
 1: .y-
\= Expect no match
    -abc.peq.
No match

/^\*\.[a-z]([a-z\-\d]*[a-z\d]+)?(\.[a-z]([a-z\-\d]*[a-z\d]+)?)*$/
    *.a
 0: *.a
    *.b0-a
 0: *.b0-a
 1: 0-a
    *.c3-b.c
 0: *.c3-b.c
 1: 3-b
 2: .c
    *.c-a.b-c
 0: *.c-a.b-c
 1: -a
 2: .b-c
 3: -c
\= Expect no match
    *.0
No match
    *.a-
No match
    *.a-b.c-
No match
    *.c-a.0-c
No match

/^(?=ab(de))(abd)(e)/
    abde
 0: abde
 1: de
 2: abd
 3: e

/^(?!(ab)de|x)(abd)(f)/
    abdf
 0: abdf
 1: <unset>
 2: abd
 3: f

/^(?=(ab(cd)))(ab)/
    abcd
 0: ab
 1: abcd
 2: cd
 3: ab

/^[\da-f](\.[\da-f])*$/i
    a.b.c.d
 0: a.b.c.d
 1: .d
    A.B.C.D
 0: A.B.C.D
 1: .D
    a.b.c.1.2.3.C
 0: a.b.c.1.2.3.C
 1: .C

/^\".*\"\s*(;.*)?$/
    \"1234\"
 0: "1234"
    \"abcd\" ;
 0: "abcd" ;
 1: ;
    \"\" ; rhubarb
 0: "" ; rhubarb
 1: ; rhubarb
\= Expect no match
    \"1234\" : things
No match

/^$/
    \
 0: 
\= Expect no match
    A non-empty line
No match

/   ^    a   (?# begins with a)  b\sc (?# then b c) $ (?# then end)/x
    ab c
 0: ab c
\= Expect no match
    abc
No match
    ab cde
No match

/(?x)   ^    a   (?# begins with a)  b\sc (?# then b c) $ (?# then end)/
    ab c
 0: ab c
\= Expect no match
    abc
No match
    ab cde
No match

/^   a\ b[c ]d       $/x
    a bcd
 0: a bcd
    a b d
 0: a b d
\= Expect no match
    abcd
No match
    ab d
No match

/^(a(b(c)))(d(e(f)))(h(i(j)))(k(l(m)))$/
    abcdefhijklm
 0: abcdefhijklm
 1: abc
 2: bc
 3: c
 4: def
 5: ef
 6: f
 7: hij
 8: ij
 9: j
10: klm
11: lm
12: m

/^(?:a(b(c)))(?:d(e(f)))(?:h(i(j)))(?:k(l(m)))$/
    abcdefhijklm
 0: abcdefhijklm
 1: bc
 2: c
 3: ef
 4: f
 5: ij
 6: j
 7: lm
 8: m

#/^[\w][\W][\s][\S][\d][\D][\b][\n][\c]][\022]/
#    a+ Z0+\x08\n\x1d\x12
# 0: a+ Z0+\x08\x0a\x1d\x12

/^[.^$|()*+?{,}]+/
    .^\$(*+)|{?,?}
 0: .^$(*+)|{?,?}

/^a*\w/
    z
 0: z
    az
 0: az
    aaaz
 0: aaaz
    a
 0: a
    aa
 0: aa
    aaaa
 0: aaaa
    a+
 0: a
    aa+
 0: aa

/^a*?\w/
    z
 0: z
    az
 0: a
    aaaz
 0: a
    a
 0: a
    aa
 0: a
    aaaa
 0: a
    a+
 0: a
    aa+
 0: a

/^a+\w/
    az
 0: az
    aaaz
 0: aaaz
    aa
 0: aa
    aaaa
 0: aaaa
    aa+
 0: aa

/^a+?\w/
    az
 0: az
    aaaz
 0: aa
    aa
 0: aa
    aaaa
 0: aa
    aa+
 0: aa

/^\d{8}\w{2,}/
    1234567890
 0: 1234567890
    12345678ab
 0: 12345678ab
    12345678__
 0: 12345678__
\= Expect no match
    1234567
No match

/^[aeiou\d]{4,5}$/
    uoie
 0: uoie
    1234
 0: 1234
    12345
 0: 12345
    aaaaa
 0: aaaaa
\= Expect no match
    123456
No match

/^[aeiou\d]{4,5}?/
    uoie
 0: uoie
    1234
 0: 1234
    12345
 0: 1234
    aaaaa
 0: aaaa
    123456
 0: 1234

/\A(abc|def)=(\1){2,3}\Z/
    abc=abcabc
 0: abc=abcabc
 1: abc
 2: abc
    def=defdefdef
 0: def=defdefdef
 1: def
 2: def
\= Expect no match
    abc=defdef
No match

/^(a)(b)(c)(d)(e)(f)(g)(h)(i)(j)(k)\11*(\3\4)\1(?#)2$/
    abcdefghijkcda2
 0: abcdefghijkcda2
 1: a
 2: b
 3: c
 4: d
 5: e
 6: f
 7: g
 8: h
 9: i
10: j
11: k
12: cd
    abcdefghijkkkkcda2
 0: abcdefghijkkkkcda2
 1: a
 2: b
 3: c
 4: d
 5: e
 6: f
 7: g
 8: h
 9: i
10: j
11: k
12: cd

/(cat(a(ract|tonic)|erpillar)) \1()2(3)/
    cataract cataract23
 0: cataract cataract23
 1: cataract
 2: aract
 3: ract
 4: 
 5: 3
    catatonic catatonic23
 0: catatonic catatonic23
 1: catatonic
 2: atonic
 3: tonic
 4: 
 5: 3
    caterpillar caterpillar23
 0: caterpillar caterpillar23
 1: caterpillar
 2: erpillar
 3: <unset>
 4: 
 5: 3


/^From +([^ ]+) +[a-zA-Z][a-zA-Z][a-zA-Z] +[a-zA-Z][a-zA-Z][a-zA-Z] +[0-9]?[0-9] +[0-9][0-9]:[0-9][0-9]/
    From abcd  Mon Sep 01 12:33:02 1997
 0: From abcd  Mon Sep 01 12:33
 1: abcd

/^From\s+\S+\s+([a-zA-Z]{3}\s+){2}\d{1,2}\s+\d\d:\d\d/
    From abcd  Mon Sep 01 12:33:02 1997
 0: From abcd  Mon Sep 01 12:33
 1: Sep 
    From abcd  Mon Sep  1 12:33:02 1997
 0: From abcd  Mon Sep  1 12:33
 1: Sep  
\= Expect no match
    From abcd  Sep 01 12:33:02 1997
No match

/^12.34/s
    12\n34
 0: 12\x0a34
    12\r34
 0: 12\x0d34

/\w+(?=\t)/
    the quick brown\t fox
 0: brown

/foo(?!bar)(.*)/
    foobar is foolish see?
 0: foolish see?
 1: lish see?

/(?:(?!foo)...|^.{0,2})bar(.*)/
    foobar crowbar etc
 0: rowbar etc
 1:  etc
    barrel
 0: barrel
 1: rel
    2barrel
 0: 2barrel
 1: rel
    A barrel
 0: A barrel
 1: rel

/^(\D*)(?=\d)(?!123)/
    abc456
 0: abc
 1: abc
\= Expect no match
    abc123
No match

/^1234(?# test newlines
  inside)/
    1234
 0: 1234

/^1234 #comment in extended re
  /x
    1234
 0: 1234

/#rhubarb
  abcd/x
    abcd
 0: abcd

/^abcd#rhubarb/x
    abcd
 0: abcd

/^(a)\1{2,3}(.)/
    aaab
 0: aaab
 1: a
 2: b
    aaaab
 0: aaaab
 1: a
 2: b
    aaaaab
 0: aaaaa
 1: a
 2: a
    aaaaaab
 0: aaaaa
 1: a
 2: a

/(?!^)abc/
    the abc
 0: abc
\= Expect no match
    abc
No match

/(?=^)abc/
    abc
 0: abc
\= Expect no match
    the abc
No match

/^[ab]{1,3}(ab*|b)/
    aabbbbb
 0: aabb
 1: b

/^[ab]{1,3}?(ab*|b)/
    aabbbbb
 0: aabbbbb
 1: abbbbb

/^[ab]{1,3}?(ab*?|b)/
    aabbbbb
 0: aa
 1: a

/^[ab]{1,3}(ab*?|b)/
    aabbbbb
 0: aabb
 1: b

/  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*                          # optional leading comment
(?:    (?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
" (?:                      # opening quote...
[^\\\x80-\xff\n\015"]                #   Anything except backslash and quote
|                     #    or
\\ [^\x80-\xff]           #   Escaped something (something != CR)
)* "  # closing quote
)                    # initial word
(?:  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*  \.  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*   (?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
" (?:                      # opening quote...
[^\\\x80-\xff\n\015"]                #   Anything except backslash and quote
|                     #    or
\\ [^\x80-\xff]           #   Escaped something (something != CR)
)* "  # closing quote
)  )* # further okay, if led by a period
(?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*  @  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*    (?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|   \[                         # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*    #    stuff
\]                        #           ]
)                           # initial subdomain
(?:                                  #
(?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*  \.                        # if led by a period...
(?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*   (?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|   \[                         # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*    #    stuff
\]                        #           ]
)                     #   ...further okay
)*
# address
|                     #  or
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
" (?:                      # opening quote...
[^\\\x80-\xff\n\015"]                #   Anything except backslash and quote
|                     #    or
\\ [^\x80-\xff]           #   Escaped something (something != CR)
)* "  # closing quote
)             # one word, optionally followed by....
(?:
[^()<>@,;:".\\\[\]\x80-\xff\000-\010\012-\037]  |  # atom and space parts, or...
\(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)       |  # comments, or...

" (?:                      # opening quote...
[^\\\x80-\xff\n\015"]                #   Anything except backslash and quote
|                     #    or
\\ [^\x80-\xff]           #   Escaped something (something != CR)
)* "  # closing quote
# quoted strings
)*
<  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*                     # leading <
(?:  @  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*    (?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|   \[                         # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*    #    stuff
\]                        #           ]
)                           # initial subdomain
(?:                                  #
(?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*  \.                        # if led by a period...
(?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*   (?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|   \[                         # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*    #    stuff
\]                        #           ]
)                     #   ...further okay
)*

(?:  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*  ,  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*  @  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*    (?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|   \[                         # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*    #    stuff
\]                        #           ]
)                           # initial subdomain
(?:                                  #
(?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*  \.                        # if led by a period...
(?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*   (?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|   \[                         # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*    #    stuff
\]                        #           ]
)                     #   ...further okay
)*
)* # further okay, if led by comma
:                                # closing colon
(?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*  )? #       optional route
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
" (?:                      # opening quote...
[^\\\x80-\xff\n\015"]                #   Anything except backslash and quote
|                     #    or
\\ [^\x80-\xff]           #   Escaped something (something != CR)
)* "  # closing quote
)                    # initial word
(?:  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*  \.  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*   (?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
" (?:                      # opening quote...
[^\\\x80-\xff\n\015"]                #   Anything except backslash and quote
|                     #    or
\\ [^\x80-\xff]           #   Escaped something (something != CR)
)* "  # closing quote
)  )* # further okay, if led by a period
(?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*  @  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*    (?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|   \[                         # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*    #    stuff
\]                        #           ]
)                           # initial subdomain
(?:                                  #
(?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*  \.                        # if led by a period...
(?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*   (?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|   \[                         # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*    #    stuff
\]                        #           ]
)                     #   ...further okay
)*
#       address spec
(?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*  > #                  trailing >
# name and address
)  (?: [\040\t] |  \(
(?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  |  \( (?:  [^\\\x80-\xff\n\015()]  |  \\ [^\x80-\xff]  )* \)  )*
\)  )*                       # optional trailing comment
/x
    Alan Other <user\@dom.ain>
 0: Alan Other <user@dom.ain>
    <user\@dom.ain>
 0: user@dom.ain
    user\@dom.ain
 0: user@dom.ain
    \"A. Other\" <user.1234\@dom.ain> (a comment)
 0: "A. Other" <user.1234@dom.ain> (a comment)
    A. Other <user.1234\@dom.ain> (a comment)
 0:  Other <user.1234@dom.ain> (a comment)
    \"/s=user/ou=host/o=place/prmd=uu.yy/admd= /c=gb/\"\@x400-re.lay
 0: "/s=user/ou=host/o=place/prmd=uu.yy/admd= /c=gb/"@x400-re.lay
    A missing angle <user\@some.where
 0: user@some.where
\= Expect no match
    The quick brown fox
No match

/[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# optional leading comment
(?:
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
# Atom
|                       #  or
"                                     # "
[^\\\x80-\xff\n\015"] *                            #   normal
(?:  \\ [^\x80-\xff]  [^\\\x80-\xff\n\015"] * )*        #   ( special normal* )*
"                                     #        "
# Quoted string
)
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
(?:
\.
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
# Atom
|                       #  or
"                                     # "
[^\\\x80-\xff\n\015"] *                            #   normal
(?:  \\ [^\x80-\xff]  [^\\\x80-\xff\n\015"] * )*        #   ( special normal* )*
"                                     #        "
# Quoted string
)
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# additional words
)*
@
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
\[                            # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*     #    stuff
\]                           #           ]
)
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# optional trailing comments
(?:
\.
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
\[                            # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*     #    stuff
\]                           #           ]
)
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# optional trailing comments
)*
# address
|                             #  or
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
# Atom
|                       #  or
"                                     # "
[^\\\x80-\xff\n\015"] *                            #   normal
(?:  \\ [^\x80-\xff]  [^\\\x80-\xff\n\015"] * )*        #   ( special normal* )*
"                                     #        "
# Quoted string
)
# leading word
[^()<>@,;:".\\\[\]\x80-\xff\000-\010\012-\037] *               # "normal" atoms and or spaces
(?:
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
|
"                                     # "
[^\\\x80-\xff\n\015"] *                            #   normal
(?:  \\ [^\x80-\xff]  [^\\\x80-\xff\n\015"] * )*        #   ( special normal* )*
"                                     #        "
) # "special" comment or quoted string
[^()<>@,;:".\\\[\]\x80-\xff\000-\010\012-\037] *            #  more "normal"
)*
<
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# <
(?:
@
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
\[                            # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*     #    stuff
\]                           #           ]
)
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# optional trailing comments
(?:
\.
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
\[                            # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*     #    stuff
\]                           #           ]
)
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# optional trailing comments
)*
(?: ,
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
@
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
\[                            # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*     #    stuff
\]                           #           ]
)
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# optional trailing comments
(?:
\.
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
\[                            # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*     #    stuff
\]                           #           ]
)
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# optional trailing comments
)*
)*  # additional domains
:
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# optional trailing comments
)?     #       optional route
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
# Atom
|                       #  or
"                                     # "
[^\\\x80-\xff\n\015"] *                            #   normal
(?:  \\ [^\x80-\xff]  [^\\\x80-\xff\n\015"] * )*        #   ( special normal* )*
"                                     #        "
# Quoted string
)
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
(?:
\.
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
# Atom
|                       #  or
"                                     # "
[^\\\x80-\xff\n\015"] *                            #   normal
(?:  \\ [^\x80-\xff]  [^\\\x80-\xff\n\015"] * )*        #   ( special normal* )*
"                                     #        "
# Quoted string
)
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# additional words
)*
@
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
\[                            # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*     #    stuff
\]                           #           ]
)
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# optional trailing comments
(?:
\.
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
(?:
[^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]+    # some number of atom characters...
(?![^(\040)<>@,;:".\\\[\]\000-\037\x80-\xff]) # ..not followed by something that could be part of an atom
|
\[                            # [
(?: [^\\\x80-\xff\n\015\[\]] |  \\ [^\x80-\xff]  )*     #    stuff
\]                           #           ]
)
[\040\t]*                    # Nab whitespace.
(?:
\(                              #  (
[^\\\x80-\xff\n\015()] *                             #     normal*
(?:                                 #       (
(?:  \\ [^\x80-\xff]  |
\(                            #  (
[^\\\x80-\xff\n\015()] *                            #     normal*
(?:  \\ [^\x80-\xff]   [^\\\x80-\xff\n\015()] * )*        #     (special normal*)*
\)                           #                       )
)    #         special
[^\\\x80-\xff\n\015()] *                         #         normal*
)*                                  #            )*
\)                             #                )
[\040\t]* )*    # If comment found, allow more spaces.
# optional trailing comments
)*
#       address spec
>                    #                 >
# name and address
)
/x
    Alan Other <user\@dom.ain>
 0: Alan Other <user@dom.ain>
    <user\@dom.ain>
 0: user@dom.ain
    user\@dom.ain
 0: user@dom.ain
    \"A. Other\" <user.1234\@dom.ain> (a comment)
 0: "A. Other" <user.1234@dom.ain>
    A. Other <user.1234\@dom.ain> (a comment)
 0:  Other <user.1234@dom.ain>
    \"/s=user/ou=host/o=place/prmd=uu.yy/admd= /c=gb/\"\@x400-re.lay
 0: "/s=user/ou=host/o=place/prmd=uu.yy/admd= /c=gb/"@x400-re.lay
    A missing angle <user\@some.where
 0: user@some.where
\= Expect no match
    The quick brown fox
No match

/abc\0def\00pqr\000xyz\0000AB/
    abc\0def\00pqr\000xyz\0000AB
 0: abc\x00def\x00pqr\x00xyz\x000AB
    abc456 abc\0def\00pqr\000xyz\0000ABCDE
 0: abc\x00def\x00pqr\x00xyz\x000AB

/abc\x0def\x00pqr\x000xyz\x0000AB/
    abc\x0def\x00pqr\x000xyz\x0000AB
 0: abc\x0def\x00pqr\x000xyz\x0000AB
    abc456 abc\x0def\x00pqr\x000xyz\x0000ABCDE
 0: abc\x0def\x00pqr\x000xyz\x0000AB

/^[\000-\037]/
    \0A
 0: \x00
    \01B
 0: \x01
    \037C
 0: \x1f

#.NET doesn't do octal with 1 number

/^(cow|)\1(bell)/
    cowcowbell
 0: cowcowbell
 1: cow
 2: bell
    bell
 0: bell
 1: 
 2: bell
\= Expect no match
    cowbell
No match

/^\s/
    \040abc
 0:  
    \x0cabc
 0: \x0c
    \nabc
 0: \x0a
    \rabc
 0: \x0d
    \tabc
 0: \x09
\= Expect no match
    abc
No match

/^a	b
      c/x
    abc
 0: abc

/^(a|)\1*b/
    ab
 0: ab
 1: a
    aaaab
 0: aaaab
 1: a
    b
 0: b
 1: 
\= Expect no match
    acb
No match

/^(a|)\1+b/
    aab
 0: aab
 1: a
    aaaab
 0: aaaab
 1: a
    b
 0: b
 1: 
\= Expect no match
    ab
No match

/^(a|)\1?b/
    ab
 0: ab
 1: a
    aab
 0: aab
 1: a
    b
 0: b
 1: 
\= Expect no match
    acb
No match

/^(a|)\1{2}b/
    aaab
 0: aaab
 1: a
    b
 0: b
 1: 
\= Expect no match
    ab
No match
    aab
No match
    aaaab
No match

/^(a|)\1{2,3}b/
    aaab
 0: aaab
 1: a
    aaaab
 0: aaaab
 1: a
    b
 0: b
 1: 
\= Expect no match
    ab
No match
    aab
No match
    aaaaab
No match

/ab{1,3}bc/
    abbbbc
 0: abbbbc
    abbbc
 0: abbbc
    abbc
 0: abbc
\= Expect no match
    abc
No match
    abbbbbc
No match

/([^.]*)\.([^:]*):[T ]+(.*)/
    track1.title:TBlah blah blah
 0: track1.title:TBlah blah blah
 1: track1
 2: title
 3: Blah blah blah

/([^.]*)\.([^:]*):[T ]+(.*)/i
    track1.title:TBlah blah blah
 0: track1.title:TBlah blah blah
 1: track1
 2: title
 3: Blah blah blah

/([^.]*)\.([^:]*):[t ]+(.*)/i
    track1.title:TBlah blah blah
 0: track1.title:TBlah blah blah
 1: track1
 2: title
 3: Blah blah blah

/^[W-c]+$/
    WXY_^abc
 0: WXY_^abc
\= Expect no match
    wxy
No match

/^[W-c]+$/i
    WXY_^abc
 0: WXY_^abc
    wxy_^ABC
 0: wxy_^ABC

/^[\x3f-\x5F]+$/i
    WXY_^abc
 0: WXY_^abc
    wxy_^ABC
 0: wxy_^ABC

/^abc$/m
    abc
 0: abc
    qqq\nabc
 0: abc
    abc\nzzz
 0: abc
    qqq\nabc\nzzz
 0: abc

/^abc$/
    abc
 0: abc
\= Expect no match
    qqq\nabc
No match
    abc\nzzz
No match
    qqq\nabc\nzzz
No match

/\Aabc\Z/m
    abc
 0: abc
    abc\n 
 0: abc
\= Expect no match
    qqq\nabc
No match
    abc\nzzz
No match
    qqq\nabc\nzzz
No match
    
/\A(.)*\Z/s
    abc\ndef
 0: abc\x0adef
 1: f

/\A(.)*\Z/m
\= Expect no match
    abc\ndef
No match

/(?:b)|(?::+)/
    b::c
 0: b
    c::b
 0: ::

/[-az]+/
    az-
 0: az-
\= Expect no match
    b
No match

/[az-]+/
    za-
 0: za-
\= Expect no match
    b
No match

/[a\-z]+/
    a-z
 0: a-z
\= Expect no match
    b
No match

/[a-z]+/
    abcdxyz
 0: abcdxyz

/[\d-]+/
    12-34
 0: 12-34
\= Expect no match
    aaa
No match

/[\d-z]+/
    12-34z
 0: 12-34z
\= Expect no match
    aaa
No match

/\x5c/
    \\
 0: \

/\x20Z/
    the Zoo
 0:  Z
\= Expect no match
    Zulu
No match

/(abc)\1/i
    abcabc
 0: abcabc
 1: abc
    ABCabc
 0: ABCabc
 1: ABC
    abcABC
 0: abcABC
 1: abc

/abc$/
    abc
 0: abc
    abc\n
 0: abc
\= Expect no match
    abc\ndef
No match

/(abc)\123/
    abc\x53
 0: abcS
 1: abc

/(abc)\100/
    abc\x40
 0: abc@
 1: abc
    abc\100
 0: abc@
 1: abc

/(abc)\1000/
    abc\x400
 0: abc@0
 1: abc
    abc\x40\x30
 0: abc@0
 1: abc
    abc\1000
 0: abc@0
 1: abc
    abc\100\x30
 0: abc@0
 1: abc
    abc\100\060
 0: abc@0
 1: abc
    abc\100\60
 0: abc@0
 1: abc
    
/^(A)(B)(C)(D)(E)(F)(G)(H)(I)\8\9$/
    ABCDEFGHIHI 
 0: ABCDEFGHIHI
 1: A
 2: B
 3: C
 4: D
 5: E
 6: F
 7: G
 8: H
 9: I

/(a)(b)(c)(d)(e)(f)(g)(h)(i)(j)(k)(l)\12\123/
    abcdefghijkllS
 0: abcdefghijkllS
 1: a
 2: b
 3: c
 4: d
 5: e
 6: f
 7: g
 8: h
 9: i
10: j
11: k
12: l

/(a)(b)(c)(d)(e)(f)(g)(h)(i)(j)(k)\12\123/
    abcdefghijk\12S
 0: abcdefghijk\x0aS
 1: a
 2: b
 3: c
 4: d
 5: e
 6: f
 7: g
 8: h
 9: i
10: j
11: k

/a{0}bc/
    bc
 0: bc

/(a|(bc)){0,0}?xyz/
    xyz
 0: xyz

/abc[\10]de/
    abc\010de
 0: abc\x08de

/abc[\1]de/
    abc\1de
 0: abc\x01de

/(abc)[\1]de/
    abc\1de
 0: abc\x01de
 1: abc

/(?s)a.b/
    a\nb
 0: a\x0ab

/^([^a])([^\b])([^c]*)([^d]{3,4})/
    baNOTccccd
 0: baNOTcccc
 1: b
 2: a
 3: NOT
 4: cccc
    baNOTcccd
 0: baNOTccc
 1: b
 2: a
 3: NOT
 4: ccc
    baNOTccd
 0: baNOTcc
 1: b
 2: a
 3: NO
 4: Tcc
    bacccd
 0: baccc
 1: b
 2: a
 3: 
 4: ccc
\= Expect no match
    anything
No match
    b\bc   
No match
    baccd
No match

/[^a]/
    Abc
 0: A
  
/[^a]/i
    Abc 
 0: b

/[^a]+/
    AAAaAbc
 0: AAA
  
/[^a]+/i
    AAAaAbc
 0: bc

/[^a]+/
    bbb\nccc
 0: bbb\x0accc
   
/[^k]$/
    abc
 0: c
\= Expect no match
    abk
No match
   
/[^k]{2,3}$/
    abc
 0: abc
    kbc
 0: bc
    kabc
 0: abc
\= Expect no match
    abk
No match
    akb
No match
    akk
No match

/^\d{8,}\@.+[^k]$/
    12345678\@a.b.c.d
 0: 12345678@a.b.c.d
    123456789\@x.y.z
 0: 123456789@x.y.z
\= Expect no match
    12345678\@x.y.uk
No match
    1234567\@a.b.c.d       
No match

/(a)\1{8,}/
    aaaaaaaaa
 0: aaaaaaaaa
 1: a
    aaaaaaaaaa
 0: aaaaaaaaaa
 1: a
\= Expect no match
    aaaaaaa   
No match

/[^a]/
    aaaabcd
 0: b
    aaAabcd 
 0: A

/[^a]/i
    aaaabcd
 0: b
    aaAabcd 
 0: b

/[^az]/
    aaaabcd
 0: b
    aaAabcd 
 0: A

/[^az]/i
    aaaabcd
 0: b
    aaAabcd 
 0: b

# trimmed upper ascii since Go is UTF-8
/\000\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037\040\041\042\043\044\045\046\047\050\051\052\053\054\055\056\057\060\061\062\063\064\065\066\067\070\071\072\073\074\075\076\077\100\101\102\103\104\105\106\107\110\111\112\113\114\115\116\117\120\121\122\123\124\125\126\127\130\131\132\133\134\135\136\137\140\141\142\143\144\145\146\147\150\151\152\153\154\155\156\157\160\161\162\163\164\165\166\167\170\171\172\173\174\175\176\177/
    \000\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037\040\041\042\043\044\045\046\047\050\051\052\053\054\055\056\057\060\061\062\063\064\065\066\067\070\071\072\073\074\075\076\077\100\101\102\103\104\105\106\107\110\111\112\113\114\115\116\117\120\121\122\123\124\125\126\127\130\131\132\133\134\135\136\137\140\141\142\143\144\145\146\147\150\151\152\153\154\155\156\157\160\161\162\163\164\165\166\167\170\171\172\173\174\175\176\177
 0: \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 !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7f

/P[^*]TAIRE[^*]{1,6}?LL/
    xxxxxxxxxxxPSTAIREISLLxxxxxxxxx
 0: PSTAIREISLL

/P[^*]TAIRE[^*]{1,}?LL/
    xxxxxxxxxxxPSTAIREISLLxxxxxxxxx
 0: PSTAIREISLL

/(\.\d\d[1-9]?)\d+/
    1.230003938
 0: .230003938
 1: .23
    1.875000282   
 0: .875000282
 1: .875
    1.235  
 0: .235
 1: .23
                  
/(\.\d\d((?=0)|\d(?=\d)))/
    1.230003938      
 0: .23
 1: .23
 2: 
    1.875000282
 0: .875
 1: .875
 2: 5
\= Expect no match 
    1.235 
No match
     
/\b(foo)\s+(\w+)/i
    Food is on the foo table
 0: foo table
 1: foo
 2: table
    
/foo(.*)bar/
    The food is under the bar in the barn.
 0: food is under the bar in the bar
 1: d is under the bar in the 
    
/foo(.*?)bar/
    The food is under the bar in the barn.
 0: food is under the bar
 1: d is under the 

/(.*)(\d*)/
    I have 2 numbers: 53147
 0: I have 2 numbers: 53147
 1: I have 2 numbers: 53147
 2: 
    
/(.*)(\d+)/
    I have 2 numbers: 53147
 0: I have 2 numbers: 53147
 1: I have 2 numbers: 5314
 2: 7
 
/(.*?)(\d*)/
    I have 2 numbers: 53147
 0: 
 1: 
 2: 

/(.*?)(\d+)/
    I have 2 numbers: 53147
 0: I have 2
 1: I have 
 2: 2

/(.*)(\d+)$/
    I have 2 numbers: 53147
 0: I have 2 numbers: 53147
 1: I have 2 numbers: 5314
 2: 7

/(.*?)(\d+)$/
    I have 2 numbers: 53147
 0: I have 2 numbers: 53147
 1: I have 2 numbers: 
 2: 53147

/(.*)\b(\d+)$/
    I have 2 numbers: 53147
 0: I have 2 numbers: 53147
 1: I have 2 numbers: 
 2: 53147

/(.*\D)(\d+)$/
    I have 2 numbers: 53147
 0: I have 2 numbers: 53147
 1: I have 2 numbers: 
 2: 53147

/^\D*(?!123)/
    ABC123
 0: AB
     
/^(\D*)(?=\d)(?!123)/
    ABC445
 0: ABC
 1: ABC
\= Expect no match
    ABC123
No match
    
/^[W-]46]/
    W46]789 
 0: W46]
    -46]789
 0: -46]
\= Expect no match
    Wall
No match
    Zebra
No match
    42
No match
    [abcd] 
No match
    ]abcd[
No match
       
/^[W-\]46]/
    W46]789 
 0: W
    Wall
 0: W
    Zebra
 0: Z
    Xylophone  
 0: X
    42
 0: 4
    [abcd] 
 0: [
    ]abcd[
 0: ]
    \\backslash 
 0: \
\= Expect no match
    -46]789
No match
    well
No match
    
/\d\d\/\d\d\/\d\d\d\d/
    01/01/2000
 0: 01/01/2000

/word (?:[a-zA-Z0-9]+ ){0,10}otherword/
    word cat dog elephant mussel cow horse canary baboon snake shark otherword
 0: word cat dog elephant mussel cow horse canary baboon snake shark otherword
\= Expect no match
    word cat dog elephant mussel cow horse canary baboon snake shark
No match

/word (?:[a-zA-Z0-9]+ ){0,300}otherword/
\= Expect no match
    word cat dog elephant mussel cow horse canary baboon snake shark the quick brown fox and the lazy dog and several other words getting close to thirty by now I hope
No match

/^(a){0,0}/
    bcd
 0: 
    abc
 0: 
    aab     
 0: 

/^(a){0,1}/
    bcd
 0: 
    abc
 0: a
 1: a
    aab  
 0: a
 1: a

/^(a){0,2}/
    bcd
 0: 
    abc
 0: a
 1: a
    aab  
 0: aa
 1: a

/^(a){0,3}/
    bcd
 0: 
    abc
 0: a
 1: a
    aab
 0: aa
 1: a
    aaa   
 0: aaa
 1: a

/^(a){0,}/
    bcd
 0: 
    abc
 0: a
 1: a
    aab
 0: aa
 1: a
    aaa
 0: aaa
 1: a
    aaaaaaaa    
 0: aaaaaaaa
 1: a

/^(a){1,1}/
    abc
 0: a
 1: a
    aab  
 0: a
 1: a
\= Expect no match
    bcd
No match

/^(a){1,2}/
    abc
 0: a
 1: a
    aab  
 0: aa
 1: a
\= Expect no match
    bcd
No match

/^(a){1,3}/
    abc
 0: a
 1: a
    aab
 0: aa
 1: a
    aaa   
 0: aaa
 1: a
\= Expect no match
    bcd
No match

/^(a){1,}/
    abc
 0: a
 1: a
    aab
 0: aa
 1: a
    aaa
 0: aaa
 1: a
    aaaaaaaa    
 0: aaaaaaaa
 1: a
\= Expect no match
    bcd
No match

/.*\.gif/
    borfle\nbib.gif\nno
 0: bib.gif

/.{0,}\.gif/
    borfle\nbib.gif\nno
 0: bib.gif

/.*\.gif/m
    borfle\nbib.gif\nno
 0: bib.gif

/.*\.gif/s
    borfle\nbib.gif\nno
 0: borfle\x0abib.gif

/.*\.gif/ms
    borfle\nbib.gif\nno
 0: borfle\x0abib.gif
    
/.*$/
    borfle\nbib.gif\nno
 0: no

/.*$/m
    borfle\nbib.gif\nno
 0: borfle

/.*$/s
    borfle\nbib.gif\nno
 0: borfle\x0abib.gif\x0ano

/.*$/ms
    borfle\nbib.gif\nno
 0: borfle\x0abib.gif\x0ano
    
/.*$/
    borfle\nbib.gif\nno\n
 0: no

/.*$/m
    borfle\nbib.gif\nno\n
 0: borfle

/.*$/s
    borfle\nbib.gif\nno\n
 0: borfle\x0abib.gif\x0ano\x0a

/.*$/ms
    borfle\nbib.gif\nno\n
 0: borfle\x0abib.gif\x0ano\x0a
    
/(.*X|^B)/
    abcde\n1234Xyz
 0: 1234X
 1: 1234X
    BarFoo 
 0: B
 1: B
\= Expect no match
    abcde\nBar  
No match

/(.*X|^B)/m
    abcde\n1234Xyz
 0: 1234X
 1: 1234X
    BarFoo 
 0: B
 1: B
    abcde\nBar  
 0: B
 1: B

/(.*X|^B)/s
    abcde\n1234Xyz
 0: abcde\x0a1234X
 1: abcde\x0a1234X
    BarFoo 
 0: B
 1: B
\= Expect no match
    abcde\nBar  
No match

/(.*X|^B)/ms
    abcde\n1234Xyz
 0: abcde\x0a1234X
 1: abcde\x0a1234X
    BarFoo 
 0: B
 1: B
    abcde\nBar  
 0: B
 1: B

/(?s)(.*X|^B)/
    abcde\n1234Xyz
 0: abcde\x0a1234X
 1: abcde\x0a1234X
    BarFoo 
 0: B
 1: B
\= Expect no match 
    abcde\nBar  
No match

/(?s:.*X|^B)/
    abcde\n1234Xyz
 0: abcde\x0a1234X
    BarFoo 
 0: B
\= Expect no match 
    abcde\nBar  
No match

/^.*B/
\= Expect no match
    abc\nB
No match
     
/(?s)^.*B/
    abc\nB
 0: abc\x0aB

/(?m)^.*B/
    abc\nB
 0: B
     
/(?ms)^.*B/
    abc\nB
 0: abc\x0aB

/(?ms)^B/
    abc\nB
 0: B

/(?s)B$/
    B\n
 0: B

/^[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]/
    123456654321
 0: 123456654321
  
/^\d\d\d\d\d\d\d\d\d\d\d\d/
    123456654321 
 0: 123456654321

/^[\d][\d][\d][\d][\d][\d][\d][\d][\d][\d][\d][\d]/
    123456654321
 0: 123456654321
  
/^[abc]{12}/
    abcabcabcabc
 0: abcabcabcabc
    
/^[a-c]{12}/
    abcabcabcabc
 0: abcabcabcabc
    
/^(a|b|c){12}/
    abcabcabcabc 
 0: abcabcabcabc
 1: c

/^[abcdefghijklmnopqrstuvwxy0123456789]/
    n
 0: n
\= Expect no match 
    z 
No match

/abcde{0,0}/
    abcd
 0: abcd
\= Expect no match
    abce  
No match

/ab[cd]{0,0}e/
    abe
 0: abe
\= Expect no match
    abcde 
No match
    
/ab(c){0,0}d/
    abd
 0: abd
\= Expect no match
    abcd   
No match

/a(b*)/
    a
 0: a
 1: 
    ab
 0: ab
 1: b
    abbbb
 0: abbbb
 1: bbbb
\= Expect no match
    bbbbb    
No match
    
/ab\d{0}e/
    abe
 0: abe
\= Expect no match
    ab1e   
No match
    
/"([^\\"]+|\\.)*"/
    the \"quick\" brown fox
 0: "quick"
 1: quick
    \"the \\\"quick\\\" brown fox\" 
 0: "the \"quick\" brown fox"
 1:  brown fox

/<tr([\w\W\s\d][^<>]{0,})><TD([\w\W\s\d][^<>]{0,})>([\d]{0,}\.)(.*)((<BR>([\w\W\s\d][^<>]{0,})|[\s]{0,}))<\/a><\/TD><TD([\w\W\s\d][^<>]{0,})>([\w\W\s\d][^<>]{0,})<\/TD><TD([\w\W\s\d][^<>]{0,})>([\w\W\s\d][^<>]{0,})<\/TD><\/TR>/is
    <TR BGCOLOR='#DBE9E9'><TD align=left valign=top>43.<a href='joblist.cfm?JobID=94 6735&Keyword='>Word Processor<BR>(N-1286)</a></TD><TD align=left valign=top>Lega lstaff.com</TD><TD align=left valign=top>CA - Statewide</TD></TR>
 0: <TR BGCOLOR='#DBE9E9'><TD align=left valign=top>43.<a href='joblist.cfm?JobID=94 6735&Keyword='>Word Processor<BR>(N-1286)</a></TD><TD align=left valign=top>Lega lstaff.com</TD><TD align=left valign=top>CA - Statewide</TD></TR>
 1:  BGCOLOR='#DBE9E9'
 2:  align=left valign=top
 3: 43.
 4: <a href='joblist.cfm?JobID=94 6735&Keyword='>Word Processor<BR>(N-1286)
 5: 
 6: 
 7: <unset>
 8:  align=left valign=top
 9: Lega lstaff.com
10:  align=left valign=top
11: CA - Statewide

/a[^a]b/
    acb
 0: acb
    a\nb
 0: a\x0ab
    
/a.b/
    acb
 0: acb
\= Expect no match 
    a\nb   
No match
    
/a[^a]b/s
    acb
 0: acb
    a\nb  
 0: a\x0ab
    
/a.b/s
    acb
 0: acb
    a\nb  
 0: a\x0ab

/^(b+?|a){1,2}?c/
    bac
 0: bac
 1: a
    bbac
 0: bbac
 1: a
    bbbac
 0: bbbac
 1: a
    bbbbac
 0: bbbbac
 1: a
    bbbbbac 
 0: bbbbbac
 1: a

/^(b+|a){1,2}?c/
    bac
 0: bac
 1: a
    bbac
 0: bbac
 1: a
    bbbac
 0: bbbac
 1: a
    bbbbac
 0: bbbbac
 1: a
    bbbbbac 
 0: bbbbbac
 1: a
    
/(?!\A)x/m
    a\bx\n
 0: x
    a\nx\n
 0: x
\= Expect no match     
    x\nb\n
No match
    
/(A|B)*?CD/
    CD 
 0: CD
    
/(A|B)*CD/
    CD 
 0: CD

/(AB)*?\1/
    ABABAB
 0: ABAB
 1: AB

/(AB)*\1/
    ABABAB
 0: ABABAB
 1: AB
    
/(?<!bar)foo/
    foo
 0: foo
    catfood
 0: foo
    arfootle
 0: foo
    rfoosh
 0: foo
\= Expect no match
    barfoo
No match
    towbarfoo
No match

/\w{3}(?<!bar)foo/
    catfood
 0: catfoo
\= Expect no match
    foo
No match
    barfoo
No match
    towbarfoo
No match

/(?<=(foo)a)bar/
    fooabar
 0: bar
 1: foo
\= Expect no match
    bar
No match
    foobbar
No match
      
/\Aabc\z/m
    abc
 0: abc
\= Expect no match
    abc\n   
No match
    qqq\nabc
No match
    abc\nzzz
No match
    qqq\nabc\nzzz
No match

"(?>.*/)foo"
    /this/is/a/very/long/line/in/deed/with/very/many/slashes/in/and/foo
 0: /this/is/a/very/long/line/in/deed/with/very/many/slashes/in/and/foo
\= Expect no match     
    /this/is/a/very/long/line/in/deed/with/very/many/slashes/in/it/you/see/
No match

/(?>(\.\d\d[1-9]?))\d+/
    1.230003938
 0: .230003938
 1: .23
    1.875000282
 0: .875000282
 1: .875
\= Expect no match 
    1.235 
No match

/^((?>\w+)|(?>\s+))*$/
    now is the time for all good men to come to the aid of the party
 0: now is the time for all good men to come to the aid of the party
 1: party
\= Expect no match
    this is not a line with only words and spaces!
No match
    
/(\d+)(\w)/
    12345a
 0: 12345a
 1: 12345
 2: a
    12345+ 
 0: 12345
 1: 1234
 2: 5

/((?>\d+))(\w)/
    12345a
 0: 12345a
 1: 12345
 2: a
\= Expect no match
    12345+ 
No match

/(?>a+)b/
    aaab
 0: aaab

/((?>a+)b)/
    aaab
 0: aaab
 1: aaab

/(?>(a+))b/
    aaab
 0: aaab
 1: aaa

/(?>b)+/
    aaabbbccc
 0: bbb

/(?>a+|b+|c+)*c/
    aaabbbbccccd
 0: aaabbbbc

/((?>[^()]+)|\([^()]*\))+/
    ((abc(ade)ufh()()x
 0: abc(ade)ufh()()x
 1: x
    
/\(((?>[^()]+)|\([^()]+\))+\)/
    (abc)
 0: (abc)
 1: abc
    (abc(def)xyz)
 0: (abc(def)xyz)
 1: xyz
\= Expect no match
    ((()aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa   
No match

/a(?-i)b/i
    ab
 0: ab
    Ab
 0: Ab
\= Expect no match 
    aB
No match
    AB
No match
        
/(a (?x)b c)d e/
    a bcd e
 0: a bcd e
 1: a bc
\= Expect no match
    a b cd e
No match
    abcd e   
No match
    a bcde 
No match
 
/(a b(?x)c d (?-x)e f)/
    a bcde f
 0: a bcde f
 1: a bcde f
\= Expect no match
    abcdef  
No match

/(a(?i)b)c/
    abc
 0: abc
 1: ab
    aBc
 0: aBc
 1: aB
\= Expect no match
    abC
No match
    aBC  
No match
    Abc
No match
    ABc
No match
    ABC
No match
    AbC
No match
    
/a(?i:b)c/
    abc
 0: abc
    aBc
 0: aBc
\= Expect no match 
    ABC
No match
    abC
No match
    aBC
No match
    
/a(?i:b)*c/
    aBc
 0: aBc
    aBBc
 0: aBBc
\= Expect no match 
    aBC
No match
    aBBC
No match
    
/a(?=b(?i)c)\w\wd/
    abcd
 0: abcd
    abCd
 0: abCd
\= Expect no match
    aBCd
No match
    abcD     
No match
    
/(?s-i:more.*than).*million/i
    more than million
 0: more than million
    more than MILLION
 0: more than MILLION
    more \n than Million 
 0: more \x0a than Million
\= Expect no match
    MORE THAN MILLION    
No match
    more \n than \n million 
No match

/(?:(?s-i)more.*than).*million/i
    more than million
 0: more than million
    more than MILLION
 0: more than MILLION
    more \n than Million 
 0: more \x0a than Million
\= Expect no match
    MORE THAN MILLION    
No match
    more \n than \n million 
No match
    
/(?>a(?i)b+)+c/
    abc
 0: abc
    aBbc
 0: aBbc
    aBBc 
 0: aBBc
\= Expect no match
    Abc
No match
    abAb    
No match
    abbC 
No match
    
/(?=a(?i)b)\w\wc/
    abc
 0: abc
    aBc
 0: aBc
\= Expect no match
    Ab 
No match
    abC
No match
    aBC     
No match
    
/(?<=a(?i)b)(\w\w)c/
    abxxc
 0: xxc
 1: xx
    aBxxc
 0: xxc
 1: xx
\= Expect no match
    Abxxc
No match
    ABxxc
No match
    abxxC      
No match

/(?:(a)|b)(?(1)A|B)/
    aA
 0: aA
 1: a
    bB
 0: bB
\= Expect no match
    aB
No match
    bA    
No match

/^(a)?(?(1)a|b)+$/
    aa
 0: aa
 1: a
    b
 0: b
    bb  
 0: bb
\= Expect no match
    ab   
No match
    
# Perl gets this next one wrong if the pattern ends with $; in that case it
# fails to match "12". 

/^(?(?=abc)\w{3}:|\d\d)/
    abc:
 0: abc:
    12
 0: 12
    123
 0: 12
\= Expect no match
    xyz    
No match

/^(?(?!abc)\d\d|\w{3}:)$/
    abc:
 0: abc:
    12
 0: 12
\= Expect no match
    123
No match
    xyz    
No match
    
/(?(?<=foo)bar|cat)/
    foobar
 0: bar
    cat
 0: cat
    fcat
 0: cat
    focat   
 0: cat
\= Expect no match
    foocat  
No match

/(?(?<!foo)cat|bar)/
    foobar
 0: bar
    cat
 0: cat
    fcat
 0: cat
    focat   
 0: cat
\= Expect no match
    foocat  
No match

/( \( )? [^()]+ (?(1) \) |) /x
    abcd
 0: abcd
    (abcd)
 0: (abcd)
 1: (
    the quick (abcd) fox
 0: the quick 
    (abcd   
 0: abcd

/( \( )? [^()]+ (?(1) \) ) /x
    abcd
 0: abcd
    (abcd)
 0: (abcd)
 1: (
    the quick (abcd) fox
 0: the quick 
    (abcd   
 0: abcd

/^(?(2)a|(1)(2))+$/
    12
 0: 12
 1: 1
 2: 2
    12a
 0: 12a
 1: 1
 2: 2
    12aa
 0: 12aa
 1: 1
 2: 2
\= Expect no match
    1234    
No match

/((?i)blah)\s+\1/
    blah blah
 0: blah blah
 1: blah
    BLAH BLAH
 0: BLAH BLAH
 1: BLAH
    Blah Blah
 0: Blah Blah
 1: Blah
    blaH blaH
 0: blaH blaH
 1: blaH
\= Expect no match
    blah BLAH
No match
    Blah blah      
No match
    blaH blah 
No match

/((?i)blah)\s+(?i:\1)/
    blah blah
 0: blah blah
 1: blah
    BLAH BLAH
 0: BLAH BLAH
 1: BLAH
    Blah Blah
 0: Blah Blah
 1: Blah
    blaH blaH
 0: blaH blaH
 1: blaH
    blah BLAH
 0: blah BLAH
 1: blah
    Blah blah      
 0: Blah blah
 1: Blah
    blaH blah 
 0: blaH blah
 1: blaH

/(?>a*)*/
    a
 0: a
    aa
 0: aa
    aaaa
 0: aaaa
    
/(abc|)+/
    abc
 0: abc
 1: 
    abcabc
 0: abcabc
 1: 
    abcabcabc
 0: abcabcabc
 1: 
    xyz      
 0: 
 1: 

/([a]*)*/
    a
 0: a
 1: 
    aaaaa 
 0: aaaaa
 1: 
 
/([ab]*)*/
    a
 0: a
 1: 
    b
 0: b
 1: 
    ababab
 0: ababab
 1: 
    aaaabcde
 0: aaaab
 1: 
    bbbb    
 0: bbbb
 1: 
 
/([^a]*)*/
    b
 0: b
 1: 
    bbbb
 0: bbbb
 1: 
    aaa   
 0: 
 1: 
 
/([^ab]*)*/
    cccc
 0: cccc
 1: 
    abab  
 0: 
 1: 
 
/([a]*?)*/
    a
 0: 
 1: 
    aaaa 
 0: 
 1: 
 
/([ab]*?)*/
    a
 0: 
 1: 
    b
 0: 
 1: 
    abab
 0: 
 1: 
    baba   
 0: 
 1: 
 
/([^a]*?)*/
    b
 0: 
 1: 
    bbbb
 0: 
 1: 
    aaa   
 0: 
 1: 
 
/([^ab]*?)*/
    c
 0: 
 1: 
    cccc
 0: 
 1: 
    baba   
 0: 
 1: 
 
/(?>a*)*/
    a
 0: a
    aaabcde 
 0: aaa
 
/((?>a*))*/
    aaaaa
 0: aaaaa
 1: 
    aabbaa 
 0: aa
 1: 
 
/((?>a*?))*/
    aaaaa
 0: 
 1: 
    aabbaa 
 0: 
 1: 

/(?(?=[^a-z]+[a-z])  \d{2}-[a-z]{3}-\d{2}  |  \d{2}-\d{2}-\d{2} ) /x
    12-sep-98
 0: 12-sep-98
    12-09-98
 0: 12-09-98
\= Expect no match
    sep-12-98
No match
        
/(?<=(foo))bar\1/
    foobarfoo
 0: barfoo
 1: foo
    foobarfootling 
 0: barfoo
 1: foo
\= Expect no match
    foobar
No match
    barfoo   
No match

/(?i:saturday|sunday)/
    saturday
 0: saturday
    sunday
 0: sunday
    Saturday
 0: Saturday
    Sunday
 0: Sunday
    SATURDAY
 0: SATURDAY
    SUNDAY
 0: SUNDAY
    SunDay
 0: SunDay
    
/(a(?i)bc|BB)x/
    abcx
 0: abcx
 1: abc
    aBCx
 0: aBCx
 1: aBC
    bbx
 0: bbx
 1: bb
    BBx
 0: BBx
 1: BB
\= Expect no match
    abcX
No match
    aBCX
No match
    bbX
No match
    BBX               
No match

/^([ab](?i)[cd]|[ef])/
    ac
 0: ac
 1: ac
    aC
 0: aC
 1: aC
    bD
 0: bD
 1: bD
    elephant
 0: e
 1: e
    Europe 
 0: E
 1: E
    frog
 0: f
 1: f
    France
 0: F
 1: F
\= Expect no match
    Africa     
No match

/^(ab|a(?i)[b-c](?m-i)d|x(?i)y|z)/
    ab
 0: ab
 1: ab
    aBd
 0: aBd
 1: aBd
    xy
 0: xy
 1: xy
    xY
 0: xY
 1: xY
    zebra
 0: z
 1: z
    Zambesi
 0: Z
 1: Z
\= Expect no match
    aCD  
No match
    XY  
No match

/(?<=foo\n)^bar/m
    foo\nbar
 0: bar
\= Expect no match
    bar
No match
    baz\nbar   
No match

/(?<=(?<!foo)bar)baz/
    barbaz
 0: baz
    barbarbaz 
 0: baz
    koobarbaz 
 0: baz
\= Expect no match
    baz
No match
    foobarbaz 
No match

# The cases of aaaa and aaaaaa are missed out below because Perl does things
# differently. We know that odd, and maybe incorrect, things happen with
# recursive references in Perl, as far as 5.11.3 - see some stuff in test #2.

/^(a\1?){4}$/
    aaaaa
 0: aaaaa
 1: a
    aaaaaaa
 0: aaaaaaa
 1: a
    aaaaaaaaaa
 0: aaaaaaaaaa
 1: aaaa
\= Expect no match
    a
No match
    aa
No match
    aaa
No match
    aaaaaaaa
No match
    aaaaaaaaa
No match
    aaaaaaaaaaa
No match
    aaaaaaaaaaaa
No match
    aaaaaaaaaaaaa
No match
    aaaaaaaaaaaaaa
No match
    aaaaaaaaaaaaaaa
No match
    aaaaaaaaaaaaaaaa
No match

/^(a\1?)(a\1?)(a\2?)(a\3?)$/
    aaaa
 0: aaaa
 1: a
 2: a
 3: a
 4: a
    aaaaa
 0: aaaaa
 1: a
 2: aa
 3: a
 4: a
    aaaaaa
 0: aaaaaa
 1: a
 2: aa
 3: a
 4: aa
    aaaaaaa
 0: aaaaaaa
 1: a
 2: aa
 3: aaa
 4: a
    aaaaaaaaaa
 0: aaaaaaaaaa
 1: a
 2: aa
 3: aaa
 4: aaaa
\= Expect no match
    a
No match
    aa
No match
    aaa
No match
    aaaaaaaa
No match
    aaaaaaaaa
No match
    aaaaaaaaaaa
No match
    aaaaaaaaaaaa
No match
    aaaaaaaaaaaaa
No match
    aaaaaaaaaaaaaa
No match
    aaaaaaaaaaaaaaa
No match
    aaaaaaaaaaaaaaaa               
No match

# The following tests are taken from the Perl 5.005 test suite; some of them
# are compatible with 5.004, but I'd rather not have to sort them out.

/abc/
    abc
 0: abc
    xabcy
 0: abc
    ababc
 0: abc
\= Expect no match
    xbc
No match
    axc
No match
    abx
No match

/ab*c/
    abc
 0: abc

/ab*bc/
    abc
 0: abc
    abbc
 0: abbc
    abbbbc
 0: abbbbc

/.{1}/
    abbbbc
 0: a

/.{3,4}/
    abbbbc
 0: abbb

/ab{0,}bc/
    abbbbc
 0: abbbbc

/ab+bc/
    abbc
 0: abbc
\= Expect no match
    abc
No match
    abq
No match

/ab{1,}bc/

/ab+bc/
    abbbbc
 0: abbbbc

/ab{1,}bc/
    abbbbc
 0: abbbbc

/ab{1,3}bc/
    abbbbc
 0: abbbbc

/ab{3,4}bc/
    abbbbc
 0: abbbbc

/ab{4,5}bc/
\= Expect no match
    abq
No match
    abbbbc
No match

/ab?bc/
    abbc
 0: abbc
    abc
 0: abc

/ab{0,1}bc/
    abc
 0: abc

/ab?bc/

/ab?c/
    abc
 0: abc

/ab{0,1}c/
    abc
 0: abc

/^abc$/
    abc
 0: abc
\= Expect no match
    abbbbc
No match
    abcc
No match

/^abc/
    abcc
 0: abc

/^abc$/

/abc$/
    aabc
 0: abc
\= Expect no match
    aabcd
No match

/^/
    abc
 0: 

/$/
    abc
 0: 

/a.c/
    abc
 0: abc
    axc
 0: axc

/a.*c/
    axyzc
 0: axyzc

/a[bc]d/
    abd
 0: abd
\= Expect no match
    axyzd
No match
    abc
No match

/a[b-d]e/
    ace
 0: ace

/a[b-d]/
    aac
 0: ac

/a[-b]/
    a-
 0: a-

/a[b-]/
    a-
 0: a-

/a]/
    a]
 0: a]

/a[]]b/
    a]b
 0: a]b

/a[^bc]d/
    aed
 0: aed
\= Expect no match
    abd
No match
    abd
No match

/a[^-b]c/
    adc
 0: adc

/a[^]b]c/
    adc
 0: adc
    a-c
 0: a-c
\= Expect no match
    a]c
No match

/\ba\b/
    a-
 0: a
    -a
 0: a
    -a-
 0: a

/\by\b/
\= Expect no match
    xy
No match
    yz
No match
    xyz
No match

/\Ba\B/
\= Expect no match
    a-
No match
    -a
No match
    -a-
No match

/\By\b/
    xy
 0: y

/\by\B/
    yz
 0: y

/\By\B/
    xyz
 0: y

/\w/
    a
 0: a

/\W/
    -
 0: -
\= Expect no match
    a
No match

/a\sb/
    a b
 0: a b

/a\Sb/
    a-b
 0: a-b
\= Expect no match
    a b
No match

/\d/
    1
 0: 1

/\D/
    -
 0: -
\= Expect no match
    1
No match

/[\w]/
    a
 0: a

/[\W]/
    -
 0: -
\= Expect no match
    a
No match

/a[\s]b/
    a b
 0: a b

/a[\S]b/
    a-b
 0: a-b
\= Expect no match
    a b
No match

/[\d]/
    1
 0: 1

/[\D]/
    -
 0: -
\= Expect no match
    1
No match

/ab|cd/
    abc
 0: ab
    abcd
 0: ab

/()ef/
    def
 0: ef
 1: 

/$b/

/a\(b/
    a(b
 0: a(b

/a\(*b/
    ab
 0: ab
    a((b
 0: a((b

/a\\b/
    a\\b
 0: a\b

/((a))/
    abc
 0: a
 1: a
 2: a

/(a)b(c)/
    abc
 0: abc
 1: a
 2: c

/a+b+c/
    aabbabc
 0: abc

/a{1,}b{1,}c/
    aabbabc
 0: abc

/a.+?c/
    abcabc
 0: abc

/(a+|b)*/
    ab
 0: ab
 1: b

/(a+|b){0,}/
    ab
 0: ab
 1: b

/(a+|b)+/
    ab
 0: ab
 1: b

/(a+|b){1,}/
    ab
 0: ab
 1: b

/(a+|b)?/
    ab
 0: a
 1: a

/(a+|b){0,1}/
    ab
 0: a
 1: a

/[^ab]*/
    cde
 0: cde

/abc/
\= Expect no match
    b
No match

/a*/
    \
 0: 

/([abc])*d/
    abbbcd
 0: abbbcd
 1: c

/([abc])*bcd/
    abcd
 0: abcd
 1: a

/a|b|c|d|e/
    e
 0: e

/(a|b|c|d|e)f/
    ef
 0: ef
 1: e

/abcd*efg/
    abcdefg
 0: abcdefg

/ab*/
    xabyabbbz
 0: ab
    xayabbbz
 0: a

/(ab|cd)e/
    abcde
 0: cde
 1: cd

/[abhgefdc]ij/
    hij
 0: hij

/^(ab|cd)e/

/(abc|)ef/
    abcdef
 0: ef
 1: 

/(a|b)c*d/
    abcd
 0: bcd
 1: b

/(ab|ab*)bc/
    abc
 0: abc
 1: a

/a([bc]*)c*/
    abc
 0: abc
 1: bc

/a([bc]*)(c*d)/
    abcd
 0: abcd
 1: bc
 2: d

/a([bc]+)(c*d)/
    abcd
 0: abcd
 1: bc
 2: d

/a([bc]*)(c+d)/
    abcd
 0: abcd
 1: b
 2: cd

/a[bcd]*dcdcde/
    adcdcde
 0: adcdcde

/a[bcd]+dcdcde/
\= Expect no match
    abcde
No match
    adcdcde
No match

/(ab|a)b*c/
    abc
 0: abc
 1: ab

/((a)(b)c)(d)/
    abcd
 0: abcd
 1: abc
 2: a
 3: b
 4: d

/[a-zA-Z_][a-zA-Z0-9_]*/
    alpha
 0: alpha

/^a(bc+|b[eh])g|.h$/
    abh
 0: bh

/(bc+d$|ef*g.|h?i(j|k))/
    effgz
 0: effgz
 1: effgz
    ij
 0: ij
 1: ij
 2: j
    reffgz
 0: effgz
 1: effgz
\= Expect no match
    effg
No match
    bcdd
No match

/((((((((((a))))))))))/
    a
 0: a
 1: a
 2: a
 3: a
 4: a
 5: a
 6: a
 7: a
 8: a
 9: a
10: a

/((((((((((a))))))))))\10/
    aa
 0: aa
 1: a
 2: a
 3: a
 4: a
 5: a
 6: a
 7: a
 8: a
 9: a
10: a

/(((((((((a)))))))))/
    a
 0: a
 1: a
 2: a
 3: a
 4: a
 5: a
 6: a
 7: a
 8: a
 9: a

/multiple words of text/
\= Expect no match
    aa
No match
    uh-uh
No match

/multiple words/
    multiple words, yeah
 0: multiple words

/(.*)c(.*)/
    abcde
 0: abcde
 1: ab
 2: de

/\((.*), (.*)\)/
    (a, b)
 0: (a, b)
 1: a
 2: b

/[k]/

/abcd/
    abcd
 0: abcd

/a(bc)d/
    abcd
 0: abcd
 1: bc

/a[-]?c/
    ac
 0: ac

/(abc)\1/
    abcabc
 0: abcabc
 1: abc

/([a-c]*)\1/
    abcabc
 0: abcabc
 1: abc

/(a)|\1/
    a
 0: a
 1: a
    ab
 0: a
 1: a
\= Expect no match
    x
No match

/(([a-c])b*?\2)*/
    ababbbcbc
 0: ababb
 1: bb
 2: b

/(([a-c])b*?\2){3}/
    ababbbcbc
 0: ababbbcbc
 1: cbc
 2: c

/((\3|b)\2(a)x)+/
    aaaxabaxbaaxbbax
 0: bbax
 1: bbax
 2: b
 3: a

/((\3|b)\2(a)){2,}/
    bbaababbabaaaaabbaaaabba
 0: bbaaaabba
 1: bba
 2: b
 3: a

/abc/i
    ABC
 0: ABC
    XABCY
 0: ABC
    ABABC
 0: ABC
\= Expect no match
    aaxabxbaxbbx
No match
    XBC
No match
    AXC
No match
    ABX
No match

/ab*c/i
    ABC
 0: ABC

/ab*bc/i
    ABC
 0: ABC
    ABBC
 0: ABBC

/ab*?bc/i
    ABBBBC
 0: ABBBBC

/ab{0,}?bc/i
    ABBBBC
 0: ABBBBC

/ab+?bc/i
    ABBC
 0: ABBC

/ab+bc/i
\= Expect no match
    ABC
No match
    ABQ
No match

/ab{1,}bc/i

/ab+bc/i
    ABBBBC
 0: ABBBBC

/ab{1,}?bc/i
    ABBBBC
 0: ABBBBC

/ab{1,3}?bc/i
    ABBBBC
 0: ABBBBC

/ab{3,4}?bc/i
    ABBBBC
 0: ABBBBC

/ab{4,5}?bc/i
\= Expect no match
    ABQ
No match
    ABBBBC
No match

/ab??bc/i
    ABBC
 0: ABBC
    ABC
 0: ABC

/ab{0,1}?bc/i
    ABC
 0: ABC

/ab??bc/i

/ab??c/i
    ABC
 0: ABC

/ab{0,1}?c/i
    ABC
 0: ABC

/^abc$/i
    ABC
 0: ABC
\= Expect no match
    ABBBBC
No match
    ABCC
No match

/^abc/i
    ABCC
 0: ABC

/^abc$/i

/abc$/i
    AABC
 0: ABC

/^/i
    ABC
 0: 

/$/i
    ABC
 0: 

/a.c/i
    ABC
 0: ABC
    AXC
 0: AXC

/a.*?c/i
    AXYZC
 0: AXYZC

/a.*c/i
    AABC
 0: AABC
\= Expect no match
    AXYZD
No match

/a[bc]d/i
    ABD
 0: ABD

/a[b-d]e/i
    ACE
 0: ACE
\= Expect no match
    ABC
No match
    ABD
No match

/a[b-d]/i
    AAC
 0: AC

/a[-b]/i
    A-
 0: A-

/a[b-]/i
    A-
 0: A-

/a]/i
    A]
 0: A]

/a[]]b/i
    A]B
 0: A]B

/a[^bc]d/i
    AED
 0: AED

/a[^-b]c/i
    ADC
 0: ADC
\= Expect no match
    ABD
No match
    A-C
No match

/a[^]b]c/i
    ADC
 0: ADC

/ab|cd/i
    ABC
 0: AB
    ABCD
 0: AB

/()ef/i
    DEF
 0: EF
 1: 

/$b/i
\= Expect no match
    A]C
No match
    B
No match

/a\(b/i
    A(B
 0: A(B

/a\(*b/i
    AB
 0: AB
    A((B
 0: A((B

/a\\b/i
    A\\b
 0: A\b
    a\\B 
 0: a\B

/((a))/i
    ABC
 0: A
 1: A
 2: A

/(a)b(c)/i
    ABC
 0: ABC
 1: A
 2: C

/a+b+c/i
    AABBABC
 0: ABC

/a{1,}b{1,}c/i
    AABBABC
 0: ABC

/a.+?c/i
    ABCABC
 0: ABC

/a.*?c/i
    ABCABC
 0: ABC

/a.{0,5}?c/i
    ABCABC
 0: ABC

/(a+|b)*/i
    AB
 0: AB
 1: B

/(a+|b){0,}/i
    AB
 0: AB
 1: B

/(a+|b)+/i
    AB
 0: AB
 1: B

/(a+|b){1,}/i
    AB
 0: AB
 1: B

/(a+|b)?/i
    AB
 0: A
 1: A

/(a+|b){0,1}/i
    AB
 0: A
 1: A

/(a+|b){0,1}?/i
    AB
 0: 

/[^ab]*/i
    CDE
 0: CDE

/([abc])*d/i
    ABBBCD
 0: ABBBCD
 1: C

/([abc])*bcd/i
    ABCD
 0: ABCD
 1: A

/a|b|c|d|e/i
    E
 0: E

/(a|b|c|d|e)f/i
    EF
 0: EF
 1: E

/abcd*efg/i
    ABCDEFG
 0: ABCDEFG

/ab*/i
    XABYABBBZ
 0: AB
    XAYABBBZ
 0: A

/(ab|cd)e/i
    ABCDE
 0: CDE
 1: CD

/[abhgefdc]ij/i
    HIJ
 0: HIJ

/^(ab|cd)e/i
\= Expect no match
    ABCDE
No match

/(abc|)ef/i
    ABCDEF
 0: EF
 1: 

/(a|b)c*d/i
    ABCD
 0: BCD
 1: B

/(ab|ab*)bc/i
    ABC
 0: ABC
 1: A

/a([bc]*)c*/i
    ABC
 0: ABC
 1: BC

/a([bc]*)(c*d)/i
    ABCD
 0: ABCD
 1: BC
 2: D

/a([bc]+)(c*d)/i
    ABCD
 0: ABCD
 1: BC
 2: D

/a([bc]*)(c+d)/i
    ABCD
 0: ABCD
 1: B
 2: CD

/a[bcd]*dcdcde/i
    ADCDCDE
 0: ADCDCDE

/a[bcd]+dcdcde/i

/(ab|a)b*c/i
    ABC
 0: ABC
 1: AB

/((a)(b)c)(d)/i
    ABCD
 0: ABCD
 1: ABC
 2: A
 3: B
 4: D

/[a-zA-Z_][a-zA-Z0-9_]*/i
    ALPHA
 0: ALPHA

/^a(bc+|b[eh])g|.h$/i
    ABH
 0: BH

/(bc+d$|ef*g.|h?i(j|k))/i
    EFFGZ
 0: EFFGZ
 1: EFFGZ
    IJ
 0: IJ
 1: IJ
 2: J
    REFFGZ
 0: EFFGZ
 1: EFFGZ
\= Expect no match
    ADCDCDE
No match
    EFFG
No match
    BCDD
No match

/((((((((((a))))))))))/i
    A
 0: A
 1: A
 2: A
 3: A
 4: A
 5: A
 6: A
 7: A
 8: A
 9: A
10: A

/((((((((((a))))))))))\10/i
    AA
 0: AA
 1: A
 2: A
 3: A
 4: A
 5: A
 6: A
 7: A
 8: A
 9: A
10: A

/(((((((((a)))))))))/i
    A
 0: A
 1: A
 2: A
 3: A
 4: A
 5: A
 6: A
 7: A
 8: A
 9: A

/(?:(?:(?:(?:(?:(?:(?:(?:(?:(a))))))))))/i
    A
 0: A
 1: A

/(?:(?:(?:(?:(?:(?:(?:(?:(?:(a|b|c))))))))))/i
    C
 0: C
 1: C

/multiple words of text/i
\= Expect no match
    AA
No match
    UH-UH
No match

/multiple words/i
    MULTIPLE WORDS, YEAH
 0: MULTIPLE WORDS

/(.*)c(.*)/i
    ABCDE
 0: ABCDE
 1: AB
 2: DE

/\((.*), (.*)\)/i
    (A, B)
 0: (A, B)
 1: A
 2: B

/[k]/i

/abcd/i
    ABCD
 0: ABCD

/a(bc)d/i
    ABCD
 0: ABCD
 1: BC

/a[-]?c/i
    AC
 0: AC

/(abc)\1/i
    ABCABC
 0: ABCABC
 1: ABC

/([a-c]*)\1/i
    ABCABC
 0: ABCABC
 1: ABC

/a(?!b)./
    abad
 0: ad

/a(?=d)./
    abad
 0: ad

/a(?=c|d)./
    abad
 0: ad

/a(?:b|c|d)(.)/
    ace
 0: ace
 1: e

/a(?:b|c|d)*(.)/
    ace
 0: ace
 1: e

/a(?:b|c|d)+?(.)/
    ace
 0: ace
 1: e
    acdbcdbe
 0: acd
 1: d

/a(?:b|c|d)+(.)/
    acdbcdbe
 0: acdbcdbe
 1: e

/a(?:b|c|d){2}(.)/
    acdbcdbe
 0: acdb
 1: b

/a(?:b|c|d){4,5}(.)/
    acdbcdbe
 0: acdbcdb
 1: b

/a(?:b|c|d){4,5}?(.)/
    acdbcdbe
 0: acdbcd
 1: d

/((foo)|(bar))*/
    foobar
 0: foobar
 1: bar
 2: foo
 3: bar

/a(?:b|c|d){6,7}(.)/
    acdbcdbe
 0: acdbcdbe
 1: e

/a(?:b|c|d){6,7}?(.)/
    acdbcdbe
 0: acdbcdbe
 1: e

/a(?:b|c|d){5,6}(.)/
    acdbcdbe
 0: acdbcdbe
 1: e

/a(?:b|c|d){5,6}?(.)/
    acdbcdbe
 0: acdbcdb
 1: b

/a(?:b|c|d){5,7}(.)/
    acdbcdbe
 0: acdbcdbe
 1: e

/a(?:b|c|d){5,7}?(.)/
    acdbcdbe
 0: acdbcdb
 1: b

/a(?:b|(c|e){1,2}?|d)+?(.)/
    ace
 0: ace
 1: c
 2: e

/^(.+)?B/
    AB
 0: AB
 1: A

/^([^a-z])|(\^)$/
    .
 0: .
 1: .

/^[<>]&/
    <&OUT
 0: <&

/^(a\1?){4}$/
    aaaaaaaaaa
 0: aaaaaaaaaa
 1: aaaa
\= Expect no match
    AB
No match
    aaaaaaaaa
No match
    aaaaaaaaaaa
No match

/^(a(?(1)\1)){4}$/
    aaaaaaaaaa
 0: aaaaaaaaaa
 1: aaaa
\= Expect no match
    aaaaaaaaa
No match
    aaaaaaaaaaa
No match

/(?:(f)(o)(o)|(b)(a)(r))*/
    foobar
 0: foobar
 1: f
 2: o
 3: o
 4: b
 5: a
 6: r

/(?<=a)b/
    ab
 0: b
\= Expect no match
    cb
No match
    b
No match

/(?<!c)b/
    ab
 0: b
    b
 0: b
    b
 0: b

/(?:..)*a/
    aba
 0: aba

/(?:..)*?a/
    aba
 0: a

/^(?:b|a(?=(.)))*\1/
    abc
 0: ab
 1: b

/^(){3,5}/
    abc
 0: 
 1: 

/^(a+)*ax/
    aax
 0: aax
 1: a

/^((a|b)+)*ax/
    aax
 0: aax
 1: a
 2: a

/^((a|bc)+)*ax/
    aax
 0: aax
 1: a
 2: a

/(a|x)*ab/
    cab
 0: ab

/(a)*ab/
    cab
 0: ab

/(?:(?i)a)b/
    ab
 0: ab

/((?i)a)b/
    ab
 0: ab
 1: a

/(?:(?i)a)b/
    Ab
 0: Ab

/((?i)a)b/
    Ab
 0: Ab
 1: A

/(?:(?i)a)b/
\= Expect no match
    cb
No match
    aB
No match

/((?i)a)b/

/(?i:a)b/
    ab
 0: ab

/((?i:a))b/
    ab
 0: ab
 1: a

/(?i:a)b/
    Ab
 0: Ab

/((?i:a))b/
    Ab
 0: Ab
 1: A

/(?i:a)b/
\= Expect no match
    aB
No match
    aB
No match

/((?i:a))b/

/(?:(?-i)a)b/i
    ab
 0: ab

/((?-i)a)b/i
    ab
 0: ab
 1: a

/(?:(?-i)a)b/i
    aB
 0: aB

/((?-i)a)b/i
    aB
 0: aB
 1: a

/(?:(?-i)a)b/i
    aB
 0: aB
\= Expect no match
    Ab
No match
    AB
No match

/(?-i:a)b/i
    ab
 0: ab

/((?-i:a))b/i
    ab
 0: ab
 1: a

/(?-i:a)b/i
    aB
 0: aB

/((?-i:a))b/i
    aB
 0: aB
 1: a

/(?-i:a)b/i
\= Expect no match
    AB
No match
    Ab
No match

/((?-i:a))b/i

/(?-i:a)b/i
    aB
 0: aB

/((?-i:a))b/i
    aB
 0: aB
 1: a

/(?-i:a)b/i
\= Expect no match
    Ab
No match
    AB
No match

/((?-i:a))b/i

/((?-i:a.))b/i
\= Expect no match
    AB
No match
    a\nB
No match

/((?s-i:a.))b/i
    a\nB
 0: a\x0aB
 1: a\x0a

/(?:c|d)(?:)(?:a(?:)(?:b)(?:b(?:))(?:b(?:)(?:b)))/
    cabbbb
 0: cabbbb

/(?:c|d)(?:)(?:aaaaaaaa(?:)(?:bbbbbbbb)(?:bbbbbbbb(?:))(?:bbbbbbbb(?:)(?:bbbbbbbb)))/
    caaaaaaaabbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
 0: caaaaaaaabbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb

/(ab)\d\1/i
    Ab4ab
 0: Ab4ab
 1: Ab
    ab4Ab
 0: ab4Ab
 1: ab

/foo\w*\d{4}baz/
    foobar1234baz
 0: foobar1234baz

/x(~~)*(?:(?:F)?)?/
    x~~
 0: x~~
 1: ~~

/^a(?#xxx){3}c/
    aaac
 0: aaac

/^a (?#xxx) (?#yyy) {3}c/x
    aaac
 0: aaac

/(?<![cd])b/
\= Expect no match
    B\nB
No match
    dbcb
No match

/(?<![cd])[ab]/
    dbaacb
 0: a

/(?<!(c|d))b/

/(?<!(c|d))[ab]/
    dbaacb
 0: a

/(?<!cd)[ab]/
    cdaccb
 0: b

/^(?:a?b?)*$/
    \
 0: 
    a
 0: a
    ab
 0: ab
    aaa   
 0: aaa
\= Expect no match
    dbcb
No match
    a--
No match
    aa-- 
No match

/((?s)^a(.))((?m)^b$)/
    a\nb\nc\n
 0: a\x0ab
 1: a\x0a
 2: \x0a
 3: b

/((?m)^b$)/
    a\nb\nc\n
 0: b
 1: b

/(?m)^b/
    a\nb\n
 0: b

/(?m)^(b)/
    a\nb\n
 0: b
 1: b

/((?m)^b)/
    a\nb\n
 0: b
 1: b

/\n((?m)^b)/
    a\nb\n
 0: \x0ab
 1: b

/((?s).)c(?!.)/
    a\nb\nc\n
 0: \x0ac
 1: \x0a
    a\nb\nc\n
 0: \x0ac
 1: \x0a

/((?s)b.)c(?!.)/
    a\nb\nc\n
 0: b\x0ac
 1: b\x0a
    a\nb\nc\n
 0: b\x0ac
 1: b\x0a

/^b/

/()^b/
\= Expect no match
    a\nb\nc\n
No match
    a\nb\nc\n
No match

/((?m)^b)/
    a\nb\nc\n
 0: b
 1: b

/(x)?(?(1)a|b)/
\= Expect no match
    a
No match
    a
No match

/(x)?(?(1)b|a)/
    a
 0: a

/()?(?(1)b|a)/
    a
 0: a

/()(?(1)b|a)/

/()?(?(1)a|b)/
    a
 0: a
 1: 

/^(\()?blah(?(1)(\)))$/
    (blah)
 0: (blah)
 1: (
 2: )
    blah
 0: blah
\= Expect no match
    a
No match
    blah)
No match
    (blah
No match

/^(\(+)?blah(?(1)(\)))$/
    (blah)
 0: (blah)
 1: (
 2: )
    blah
 0: blah
\= Expect no match
    blah)
No match
    (blah
No match

/(?(?!a)a|b)/

/(?(?!a)b|a)/
    a
 0: a

/(?(?=a)b|a)/
\= Expect no match
    a
No match
    a
No match

/(?(?=a)a|b)/
    a
 0: a

/(?=(a+?))(\1ab)/
    aaab
 0: aab
 1: a
 2: aab

/^(?=(a+?))\1ab/

/(\w+:)+/
    one:
 0: one:
 1: one:

/$(?<=^(a))/
    a
 0: 
 1: a

/(?=(a+?))(\1ab)/
    aaab
 0: aab
 1: a
 2: aab

/^(?=(a+?))\1ab/
\= Expect no match
    aaab
No match
    aaab
No match

/([\w:]+::)?(\w+)$/
    abcd
 0: abcd
 1: <unset>
 2: abcd
    xy:z:::abcd
 0: xy:z:::abcd
 1: xy:z:::
 2: abcd

/^[^bcd]*(c+)/
    aexycd
 0: aexyc
 1: c

/(a*)b+/
    caab
 0: aab
 1: aa

/([\w:]+::)?(\w+)$/
    abcd
 0: abcd
 1: <unset>
 2: abcd
    xy:z:::abcd
 0: xy:z:::abcd
 1: xy:z:::
 2: abcd
\= Expect no match
    abcd:
No match
    abcd:
No match

/^[^bcd]*(c+)/
    aexycd
 0: aexyc
 1: c

/(>a+)ab/

/(?>a+)b/
    aaab
 0: aaab

/([[:]+)/
    a:[b]:
 0: :[
 1: :[

/([[=]+)/
    a=[b]=
 0: =[
 1: =[

/([[.]+)/
    a.[b].
 0: .[
 1: .[

/((?>a+)b)/
    aaab
 0: aaab
 1: aaab

/(?>(a+))b/
    aaab
 0: aaab
 1: aaa

/((?>[^()]+)|\([^()]*\))+/
    ((abc(ade)ufh()()x
 0: abc(ade)ufh()()x
 1: x

/a\Z/
\= Expect no match
    aaab
No match
    a\nb\n
No match

/b\Z/
    a\nb\n
 0: b

/b\z/

/b\Z/
    a\nb
 0: b

/b\z/
    a\nb
 0: b
    
/^(?>(?(1)\.|())[^\W_](?>[a-z0-9-]*[^\W_])?)+$/
    a
 0: a
 1: 
    abc
 0: abc
 1: 
    a-b
 0: a-b
 1: 
    0-9
 0: 0-9
 1: 
    a.b
 0: a.b
 1: 
    5.6.7
 0: 5.6.7
 1: 
    the.quick.brown.fox
 0: the.quick.brown.fox
 1: 
    a100.b200.300c
 0: a100.b200.300c
 1: 
    12-ab.1245
 0: 12-ab.1245
 1: 
\= Expect no match
    \
No match
    .a
No match
    -a
No match
    a-
No match
    a.
No match
    a_b
No match
    a.-
No match
    a..
No match
    ab..bc
No match
    the.quick.brown.fox-
No match
    the.quick.brown.fox.
No match
    the.quick.brown.fox_
No match
    the.quick.brown.fox+
No match

/(?>.*)(?<=(abcd|wxyz))/
    alphabetabcd
 0: alphabetabcd
 1: abcd
    endingwxyz
 0: endingwxyz
 1: wxyz
\= Expect no match
    a rather long string that doesn't end with one of them
No match

/word (?>(?:(?!otherword)[a-zA-Z0-9]+ ){0,30})otherword/
    word cat dog elephant mussel cow horse canary baboon snake shark otherword
 0: word cat dog elephant mussel cow horse canary baboon snake shark otherword
\= Expect no match
    word cat dog elephant mussel cow horse canary baboon snake shark
No match
  
/word (?>[a-zA-Z0-9]+ ){0,30}otherword/
\= Expect no match
    word cat dog elephant mussel cow horse canary baboon snake shark the quick brown fox and the lazy dog and several other words getting close to thirty by now I hope
No match

/(?<=\d{3}(?!999))foo/
    999foo
 0: foo
    123999foo 
 0: foo
\= Expect no match
    123abcfoo
No match
    
/(?<=(?!...999)\d{3})foo/
    999foo
 0: foo
    123999foo 
 0: foo
\= Expect no match
    123abcfoo
No match

/(?<=\d{3}(?!999)...)foo/
    123abcfoo
 0: foo
    123456foo 
 0: foo
\= Expect no match
    123999foo  
No match
    
/(?<=\d{3}...)(?<!999)foo/
    123abcfoo   
 0: foo
    123456foo 
 0: foo
\= Expect no match
    123999foo  
No match

/((Z)+|A)*/
    ZABCDEFG
 0: ZA
 1: A
 2: Z

/(Z()|A)*/
    ZABCDEFG
 0: ZA
 1: A
 2: 

/(Z(())|A)*/
    ZABCDEFG
 0: ZA
 1: A
 2: 
 3: 

/((?>Z)+|A)*/
    ZABCDEFG
 0: ZA
 1: A

/((?>)+|A)*/
    ZABCDEFG
 0: 
 1: 

/^[\d-a]/
    abcde
 0: a
    -things
 0: -
    0digit
 0: 0
\= Expect no match
    bcdef    
No match
    
/[\s]+/
    > \x09\x0a\x0c\x0d\x0b<
 0:  \x09\x0a\x0c\x0d\x0b
     
/\s+/
    > \x09\x0a\x0c\x0d\x0b<
 0:  \x09\x0a\x0c\x0d\x0b
     
/ab/x
    ab
 0: ab

/(?!\A)x/m
    a\nxb\n
 0: x

/(?!^)x/m
\= Expect no match
    a\nxb\n
No match

#/abc\Qabc\Eabc/
#    abcabcabc
# 0: abcabcabc
    
#/abc\Q(*+|\Eabc/
#    abc(*+|abc 
# 0: abc(*+|abc

#/   abc\Q abc\Eabc/x
#    abc abcabc
# 0: abc abcabc
#\= Expect no match
#    abcabcabc  
#No match
    
#/abc#comment
#    \Q#not comment
#    literal\E/x
#    abc#not comment\n    literal     
# 0: abc#not comment\x0a    literal

#/abc#comment
#    \Q#not comment
#    literal/x
#    abc#not comment\n    literal     
# 0: abc#not comment\x0a    literal

#/abc#comment
#    \Q#not comment
#    literal\E #more comment
#    /x
#    abc#not comment\n    literal     
# 0: abc#not comment\x0a    literal

#/abc#comment
#    \Q#not comment
#    literal\E #more comment/x
#    abc#not comment\n    literal     
# 0: abc#not comment\x0a    literal

#/\Qabc\$xyz\E/
#    abc\\\$xyz
# 0: abc\$xyz

#/\Qabc\E\$\Qxyz\E/
#    abc\$xyz
# 0: abc$xyz

/\Gabc/
    abc
 0: abc
\= Expect no match
    xyzabc  
No match

/a(?x: b c )d/
    XabcdY
 0: abcd
\= Expect no match 
    Xa b c d Y 
No match

/((?x)x y z | a b c)/
    XabcY
 0: abc
 1: abc
    AxyzB 
 0: xyz
 1: xyz

/(?i)AB(?-i)C/
    XabCY
 0: abC
\= Expect no match
    XabcY  
No match

/((?i)AB(?-i)C|D)E/
    abCE
 0: abCE
 1: abC
    DE
 0: DE
 1: D
\= Expect no match
    abcE
No match
    abCe  
No match
    dE
No match
    De    
No match

/(.*)\d+\1/
    abc123abc
 0: abc123abc
 1: abc
    abc123bc 
 0: bc123bc
 1: bc

/(.*)\d+\1/s
    abc123abc
 0: abc123abc
 1: abc
    abc123bc 
 0: bc123bc
 1: bc
    
/((.*))\d+\1/
    abc123abc
 0: abc123abc
 1: abc
 2: abc
    abc123bc  
 0: bc123bc
 1: bc
 2: bc

# This tests for an IPv6 address in the form where it can have up to
# eight components, one and only one of which is empty. This must be
# an internal component. 

/^(?!:)                       # colon disallowed at start
  (?:                         # start of item
    (?: [0-9a-f]{1,4} |       # 1-4 hex digits or
    (?(1)0 | () ) )           # if null previously matched, fail; else null
    :                         # followed by colon
  ){1,7}                      # end item; 1-7 of them required               
  [0-9a-f]{1,4} $             # final hex number at end of string
  (?(1)|.)                    # check that there was an empty component
  /ix
    a123::a123
 0: a123::a123
 1: 
    a123:b342::abcd
 0: a123:b342::abcd
 1: 
    a123:b342::324e:abcd
 0: a123:b342::324e:abcd
 1: 
    a123:ddde:b342::324e:abcd
 0: a123:ddde:b342::324e:abcd
 1: 
    a123:ddde:b342::324e:dcba:abcd
 0: a123:ddde:b342::324e:dcba:abcd
 1: 
    a123:ddde:9999:b342::324e:dcba:abcd
 0: a123:ddde:9999:b342::324e:dcba:abcd
 1: 
\= Expect no match
    1:2:3:4:5:6:7:8
No match
    a123:bce:ddde:9999:b342::324e:dcba:abcd
No match
    a123::9999:b342::324e:dcba:abcd
No match
    abcde:2:3:4:5:6:7:8
No match
    ::1
No match
    abcd:fee0:123::   
No match
    :1
No match
    1:  
No match

#/[z\Qa-d]\E]/
#    z
# 0: z
#    a
# 0: a
#    -
# 0: -
#    d
# 0: d
#    ] 
# 0: ]
#\= Expect no match
#    b     
#No match

#TODO: PCRE has an optimization to make this workable, .NET does not
#/(a+)*b/
#\= Expect no match
#    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 
#No match

# All these had to be updated because we understand unicode
# and this looks like it's expecting single byte matches

# .NET generates \xe4...not sure what's up, might just be different code pages
/(?i)reg(?:ul(?:[aä]|ae)r|ex)/
    REGular
 0: REGular
    regulaer
 0: regulaer
    Regex  
 0: Regex
    regulär 
 0: regul\xc3\xa4r

#/Åæåä[à-ÿÀ-ß]+/
#    Åæåäà
# 0: \xc5\xe6\xe5\xe4\xe0
#    Åæåäÿ
# 0: \xc5\xe6\xe5\xe4\xff
#    ÅæåäÀ
# 0: \xc5\xe6\xe5\xe4\xc0
#    Åæåäß
# 0: \xc5\xe6\xe5\xe4\xdf

/(?<=Z)X./
    \x84XAZXB
 0: XB

/ab cd (?x) de fg/
    ab cd defg
 0: ab cd defg

/ab cd(?x) de fg/
    ab cddefg
 0: ab cddefg
\= Expect no match 
    abcddefg
No match

/(?<![^f]oo)(bar)/
    foobarX 
 0: bar
 1: bar
\= Expect no match 
    boobarX
No match

/(?<![^f])X/
    offX
 0: X
\= Expect no match
    onyX  
No match

/(?<=[^f])X/
    onyX
 0: X
\= Expect no match
    offX 
No match

/(?:(?(1)a|b)(X))+/
    bXaX
 0: bXaX
 1: X

/(?:(?(1)\1a|b)(X|Y))+/
    bXXaYYaY
 0: bXXaYYaY
 1: Y
    bXYaXXaX  
 0: bX
 1: X

# TODO: I think this is a difference caused by the 
# collision of group numbers, but not sure 
#/()()()()()()()()()(?:(?(10)\10a|b)(X|Y))+/
#    bXXaYYaY
# 0: bX
# 1: 
# 2: 
# 3: 
# 4: 
# 5: 
# 6: 
# 7: 
# 8: 
# 9: 
#10: X

/[[,abc,]+]/
    abc]
 0: abc]
    a,b]
 0: a,b]
    [a,b,c]  
 0: [a,b,c]

/(?-x: )/x
    A\x20B
 0:  
    
"(?x)(?-x: \s*#\s*)"
    A # B
 0:  # 
\= Expect no match
    #  
No match

"(?x-is)(?:(?-ixs) \s*#\s*) include"
    A #include
 0:  #include
\= Expect no match
    A#include  
No match
    A #Include
No match

/a*b*\w/
    aaabbbb
 0: aaabbbb
    aaaa
 0: aaaa
    a
 0: a

/a*b?\w/
    aaabbbb
 0: aaabb
    aaaa
 0: aaaa
    a
 0: a

/a*b{0,4}\w/
    aaabbbb
 0: aaabbbb
    aaaa
 0: aaaa
    a
 0: a

/a*b{0,}\w/
    aaabbbb
 0: aaabbbb
    aaaa
 0: aaaa
    a
 0: a
    
/a*\d*\w/
    0a
 0: 0a
    a 
 0: a
    
/a*b *\w/x
    a 
 0: a

/a*b#comment
  *\w/x
    a 
 0: a

/a* b *\w/x
    a 
 0: a

/^\w+=.*(\\\n.*)*/
    abc=xyz\\\npqr
 0: abc=xyz\

/(?=(\w+))\1:/
    abcd:
 0: abcd:
 1: abcd

/^(?=(\w+))\1:/
    abcd:
 0: abcd:
 1: abcd

#/^\Eabc/
#    abc
# 0: abc
    
#/^[\Eabc]/
#    a
# 0: a
#\= Expect no match 
#    E 
#No match
    
#/^[a-\Ec]/
#    b
# 0: b
#\= Expect no match
#    -
#No match
#    E    
#No match

#/^[a\E\E-\Ec]/
#    b
# 0: b
#\= Expect no match
#    -
#No match
#    E    
#No match

#/^[\E\Qa\E-\Qz\E]+/
#    b
# 0: b
#\= Expect no match
#    -  
#No match
    
#/^[a\Q]bc\E]/
#    a
# 0: a
#    ]
# 0: ]
#    c
# 0: c
    
#/^[a-\Q\E]/
#    a
# 0: a
#    -     
# 0: -

/^(a()*)*/
    aaaa
 0: aaaa
 1: a
 2: 

/^(?:a(?:(?:))*)*/
    aaaa
 0: aaaa

/^(a()+)+/
    aaaa
 0: aaaa
 1: a
 2: 

/^(?:a(?:(?:))+)+/
    aaaa
 0: aaaa

/(a){0,3}(?(1)b|(c|))*D/
    abbD
 0: abbD
 1: a
    ccccD
 0: ccccD
 1: <unset>
 2: 
    D  
 0: D
 1: <unset>
 2: 

# this is really long with debug -- removing for now
#/(a|)*\d/
#    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa4
# 0: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa4
# 1: 
#\= Expect no match
#    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
#No match

/(?>a|)*\d/
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa4
 0: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa4
\= Expect no match
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
No match

/(?:a|)*\d/
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa4
 0: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa4
\= Expect no match
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
No match

/^(?s)(?>.*)(?<!\n)/
    abc
 0: abc
\= Expect no match
    abc\n  
No match

/^(?![^\n]*\n\z)/
    abc
 0: 
\= Expect no match
    abc\n 
No match
  
/\z(?<!\n)/
    abc
 0: 
\= Expect no match
    abc\n  
No match

/(.*(.)?)*/
    abcd
 0: abcd
 1: 

/( (A | (?(1)0|) )*   )/x
    abcd
 0: 
 1: 
 2: 

/( ( (?(1)0|) )*   )/x
    abcd
 0: 
 1: 
 2: 

/(  (?(1)0|)*   )/x
    abcd
 0: 
 1: 

/[[:abcd:xyz]]/
    a]
 0: a]
    :] 
 0: :]
    
/[abc[:x\]pqr]/
    a
 0: a
    [
 0: [
    :
 0: :
    ]
 0: ]
    p    
 0: p

/.*[op][xyz]/
\= Expect no match
    fooabcfoo
No match

/(?(?=.*b)b|^)/
    adc
 0: 
    abc 
 0: b

/(?(?=^.*b)b|^)/
    adc
 0: 
\= Expect no match
    abc 
No match

/(?(?=.*b)b|^)*/
    adc
 0: 
    abc 
 0: 

/(?(?=.*b)b|^)+/
    adc
 0: 
    abc 
 0: b

/(?(?=b).*b|^d)/
    abc
 0: b

/(?(?=.*b).*b|^d)/
    abc
 0: ab

/^%((?(?=[a])[^%])|b)*%$/
    %ab%
 0: %ab%
 1: 

/(?i)a(?-i)b|c/
    XabX
 0: ab
    XAbX
 0: Ab
    CcC 
 0: c
\= Expect no match
    XABX   
No match

/[\x00-\xff\s]+/
    \x0a\x0b\x0c\x0d
 0: \x0a\x0b\x0c\x0d

/(abc)\1/i
\= Expect no match
    abc
No match

/(abc)\1/
\= Expect no match
    abc
No match

/[^a]*/i
    12abc
 0: 12
    12ABC
 0: 12

#Posses
/[^a]*/i
    12abc
 0: 12
    12ABC
 0: 12

/[^a]*?X/i
\= Expect no match
    12abc
No match
    12ABC
No match
    
/[^a]+?X/i
\= Expect no match
    12abc
No match
    12ABC
No match

/[^a]?X/i
    12aXbcX
 0: X
    12AXBCX
 0: X
    BCX 
 0: CX

/[^a]??X/i
    12aXbcX
 0: X
    12AXBCX
 0: X
    BCX
 0: CX

/[^a]{2,3}/i
    abcdef
 0: bcd
    ABCDEF  
 0: BCD

/[^a]{2,3}?/i
    abcdef
 0: bc
    ABCDEF  
 0: BC

/((a|)+)+Z/
    Z
 0: Z
 1: 
 2: 

/(a)b|(a)c/
    ac
 0: ac
 1: <unset>
 2: a

/(?>(a))b|(a)c/
    ac
 0: ac
 1: <unset>
 2: a

/(?=(a))ab|(a)c/
    ac
 0: ac
 1: <unset>
 2: a

/((?>(a))b|(a)c)/
    ac
 0: ac
 1: ac
 2: <unset>
 3: a

/(?=(?>(a))b|(a)c)(..)/
    ac
 0: ac
 1: <unset>
 2: a
 3: ac

/(?>(?>(a))b|(a)c)/
    ac
 0: ac
 1: <unset>
 2: a

/((?>(a+)b)+(aabab))/
    aaaabaaabaabab
 0: aaaabaaabaabab
 1: aaaabaaabaabab
 2: aaa
 3: aabab

/(?>a+|ab)+?c/
\= Expect no match
    aabc
No match

/(?>a+|ab)+c/
\= Expect no match
    aabc
No match

/(?:a+|ab)+c/
    aabc
 0: aabc

/^(?:a|ab)+c/
    aaaabc
 0: aaaabc

/(?=abc){0}xyz/
    xyz 
 0: xyz

/(?=abc){1}xyz/
\= Expect no match
    xyz 
No match
    
/(?=(a))?./
    ab
 0: a
 1: a
    bc
 0: b
      
/(?=(a))??./
    ab
 0: a
    bc
 0: b

/^(?!a){0}\w+/
    aaaaa
 0: aaaaa

/(?<=(abc))?xyz/
    abcxyz
 0: xyz
 1: abc
    pqrxyz 
 0: xyz

/^[g<a>]+/
    ggg<<<aaa>>>
 0: ggg<<<aaa>>>
\= Expect no match
    \\ga  
No match
    
/^[ga]+/
    gggagagaxyz 
 0: gggagaga
   
/[:a]xxx[b:]/
     :xxx:
 0: :xxx:
     
/(?<=a{2})b/i
    xaabc
 0: b
\= Expect no match
    xabc  
No match

/(?<!a{2})b/i
    xabc
 0: b
\= Expect no match
    xaabc  
No match
    
/(?<=[^a]{2})b/
    axxbc
 0: b
    aAAbc 
 0: b
\= Expect no match
    xaabc    
No match

/(?<=[^a]{2})b/i
    axxbc  
 0: b
\= Expect no match
    aAAbc 
No match
    xaabc    
No match

#/(?|(abc)|(xyz))\1/
#    abcabc
# 0: abcabc
# 1: abc
#    xyzxyz 
# 0: xyzxyz
# 1: xyz
#\= Expect no match
#    abcxyz
#No match
#    xyzabc   
#No match
    
#/(?|(abc)|(xyz))(?1)/
#    abcabc
# 0: abcabc
# 1: abc
#    xyzabc 
# 0: xyzabc
# 1: xyz
#\= Expect no match 
#    xyzxyz 
#No match
 
#/^X(?5)(a)(?|(b)|(q))(c)(d)(Y)/
#    XYabcdY
# 0: XYabcdY
# 1: a
# 2: b
# 3: c
# 4: d
# 5: Y

#/^X(?7)(a)(?|(b|(r)(s))|(q))(c)(d)(Y)/
#    XYabcdY
# 0: XYabcdY
# 1: a
# 2: b
# 3: <unset>
# 4: <unset>
# 5: c
# 6: d
# 7: Y

#/^X(?7)(a)(?|(b|(?|(r)|(t))(s))|(q))(c)(d)(Y)/
#    XYabcdY
# 0: XYabcdY
# 1: a
# 2: b
# 3: <unset>
# 4: <unset>
# 5: c
# 6: d
# 7: Y

/(?'abc'\w+):\k<abc>{2}/
    a:aaxyz
 0: a:aa
 1: a
    ab:ababxyz
 0: ab:abab
 1: ab
\= Expect no match
    a:axyz
No match
    ab:abxyz
No match

/^(?<ab>a)? (?(ab)b|c) (?(ab)d|e)/x
    abd
 0: abd
 1: a
    ce
 0: ce
    
# .NET has more consistent grouping numbers with these dupe groups for the two options
/(?:a(?<quote> (?<apostrophe>')|(?<realquote>")) |b(?<quote> (?<apostrophe>')|(?<realquote>")) ) (?(quote)[a-z]+|[0-9]+)/x,dupnames
    a\"aaaaa
 0: a"aaaaa
 1: "
 2: <unset>
 3: "
    b\"aaaaa
 0: b"aaaaa
 1: "
 2: <unset>
 3: "
\= Expect no match 
    b\"11111
No match

#/(?P<L1>(?P<L2>0)(?P>L1)|(?P>L2))/
#    0
# 0: 0
# 1: 0
#    00
# 0: 00
# 1: 00
# 2: 0
#    0000  
# 0: 0000
# 1: 0000
# 2: 0

#/(?P<L1>(?P<L2>0)|(?P>L2)(?P>L1))/
#    0
# 0: 0
# 1: 0
# 2: 0
#    00
# 0: 0
# 1: 0
# 2: 0
#    0000  
# 0: 0
# 1: 0
# 2: 0

# Check the use of names for failure

# Check opening parens in comment when seeking forward reference.

#/(?P<abn>(?P=abn)xxx|)+/
#    xxx
# 0: 
# 1: 

#Posses
/^(a)?(\w)/
    aaaaX
 0: aa
 1: a
 2: a
    YZ 
 0: Y
 1: <unset>
 2: Y

#Posses
/^(?:a)?(\w)/
    aaaaX
 0: aa
 1: a
    YZ 
 0: Y
 1: Y

/\A.*?(a|bc)/
    ba
 0: ba
 1: a

/\A.*?(?:a|bc|d)/
    ba
 0: ba

# --------------------------

/(another)?(\1?)test/
    hello world test
 0: test
 1: <unset>
 2: 

/(another)?(\1+)test/
\= Expect no match
    hello world test
No match

/((?:a?)*)*c/
    aac   
 0: aac
 1: 

/((?>a?)*)*c/
    aac   
 0: aac
 1: 

/(?>.*?a)(?<=ba)/
    aba
 0: ba

/(?:.*?a)(?<=ba)/
    aba
 0: aba

/(?>.*?a)b/s
    aab
 0: ab

/(?>.*?a)b/
    aab
 0: ab

/(?>^a)b/s
\= Expect no match
    aab
No match

/(?>.*?)(?<=(abcd)|(wxyz))/
    alphabetabcd
 0: 
 1: abcd
    endingwxyz 
 0: 
 1: <unset>
 2: wxyz

/(?>.*)(?<=(abcd)|(wxyz))/
    alphabetabcd
 0: alphabetabcd
 1: abcd
    endingwxyz
 0: endingwxyz
 1: <unset>
 2: wxyz

"(?>.*)foo"
\= Expect no match
    abcdfooxyz
No match
    
"(?>.*?)foo"
    abcdfooxyz
 0: foo

# Tests that try to figure out how Perl works. My hypothesis is that the first
# verb that is backtracked onto is the one that acts. This seems to be the case
# almost all the time, but there is one exception that is perhaps a bug.
 
/a(?=bc).|abd/
    abd
 0: abd
    abc 
 0: ab
  
/a(?>bc)d|abd/
    abceabd 
 0: abd

# These tests were formerly in test 2, but changes in PCRE and Perl have
# made them compatible. 
    
/^(a)?(?(1)a|b)+$/
\= Expect no match
    a
No match

# ----

/^\d*\w{4}/
    1234
 0: 1234
\= Expect no match
    123 
No match

/^[^b]*\w{4}/
    aaaa
 0: aaaa
\= Expect no match
    aaa     
No match

/^[^b]*\w{4}/i
    aaaa
 0: aaaa
\= Expect no match
    aaa     
No match

/^a*\w{4}/
    aaaa
 0: aaaa
\= Expect no match
    aaa     
No match

/^a*\w{4}/i
    aaaa
 0: aaaa
\= Expect no match
    aaa     
No match

/(?:(?<n>foo)|(?<n>bar))\k<n>/dupnames
    foofoo
 0: foofoo
 1: foo
    barbar
 0: barbar
 1: bar

# A notable difference between PCRE and .NET.  According to
# the PCRE docs:
# If you make a subroutine call to a non-unique named 
# subpattern, the one that corresponds  to  the first 
# occurrence of the name is used. In the absence of 
# duplicate numbers (see the previous section) this is 
# the one with the lowest number.
# .NET takes the most recently captured number according to MSDN:
# A backreference refers to the most recent definition of 
# a group (the definition most immediately to the left, 
# when matching left to right). When a group makes multiple
# captures, a backreference refers to the most recent capture.

#/(?<n>A)(?:(?<n>foo)|(?<n>bar))\k<n>/dupnames
#    AfooA
# 0: AfooA
# 1: A
# 2: foo
#    AbarA  
# 0: AbarA
# 1: A
# 2: <unset>
# 3: bar
#\= Expect no match 
#    Afoofoo
#No match
#    Abarbar
#No match

/^(\d+)\s+IN\s+SOA\s+(\S+)\s+(\S+)\s*\(\s*$/
    1 IN SOA non-sp1 non-sp2(
 0: 1 IN SOA non-sp1 non-sp2(
 1: 1
 2: non-sp1
 3: non-sp2

# TODO: .NET's group number ordering here in the second example is a bit odd
/^ (?:(?<A>A)|(?'B'B)(?<A>A)) (?(A)x) (?(B)y)$/x,dupnames
    Ax
 0: Ax
 1: A
    BAxy
 0: BAxy
 1: A
 2: B
 
/ ^ a + b $ /x
    aaaab
 0: aaaab
    
/ ^ a + #comment
   b $ /x
    aaaab
 0: aaaab
    
/ ^ a + #comment
  #comment
   b $ /x
    aaaab
 0: aaaab
    
/ ^ (?> a + ) b $ /x
    aaaab 
 0: aaaab

/ ^ ( a + ) + \w $ /x
    aaaab 
 0: aaaab
 1: aaaa

/(?:x|(?:(xx|yy)+|x|x|x|x|x)|a|a|a)bc/
\= Expect no match
    acb
No match

#Posses
#/\A(?:[^\"]+|\"(?:[^\"]*|\"\")*\")+/
#    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED
# 0: NON QUOTED "QUOT""ED" AFTER 

#Posses
#/\A(?:[^\"]+|\"(?:[^\"]+|\"\")*\")+/
#    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED
# 0: NON QUOTED "QUOT""ED" AFTER 

#Posses
#/\A(?:[^\"]+|\"(?:[^\"]+|\"\")+\")+/
#    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED
# 0: NON QUOTED "QUOT""ED" AFTER 

#Posses
#/\A([^\"1]+|[\"2]([^\"3]*|[\"4][\"5])*[\"6])+/
#    NON QUOTED \"QUOT\"\"ED\" AFTER \"NOT MATCHED
# 0: NON QUOTED "QUOT""ED" AFTER 
# 1:  AFTER 
# 2: 

/^\w+(?>\s*)(?<=\w)/
    test test
 0: tes

#/(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
#    acl
# 0: acl
# 1: a
#    bdl
# 0: bdl
# 1: <unset>
# 2: b
#    adl
# 0: dl
#    bcl    
# 0: l

/\sabc/
    \x0babc
 0: \x0babc

#/[\Qa]\E]+/
#    aa]]
# 0: aa]]

#/[\Q]a\E]+/
#    aa]]
# 0: aa]]

/A((((((((a))))))))\8B/ 
    AaaB
 0: AaaB
 1: a
 2: a
 3: a
 4: a
 5: a
 6: a
 7: a
 8: a

/A(((((((((a)))))))))\9B/ 
    AaaB
 0: AaaB
 1: a
 2: a
 3: a
 4: a
 5: a
 6: a
 7: a
 8: a
 9: a
    
/(|ab)*?d/
    abd
 0: abd
 1: ab
    xyd 
 0: d

/(\2|a)(\1)/
    aaa
 0: aa
 1: a
 2: a

/(\2)(\1)/

"Z*(|d*){216}"

/((((((((((((x))))))))))))\12/
    xx
 0: xx
 1: x
 2: x
 3: x
 4: x
 5: x
 6: x
 7: x
 8: x
 9: x
10: x
11: x
12: x

#"(?|(\k'Pm')|(?'Pm'))"
#    abcd
# 0: 
# 1: 

#/(?|(aaa)|(b))\g{1}/
#    aaaaaa
# 0: aaaaaa
# 1: aaa
#    bb 
# 0: bb
# 1: b

#/(?|(aaa)|(b))(?1)/
#    aaaaaa
# 0: aaaaaa
# 1: aaa
#    baaa 
# 0: baaa
# 1: b
#\= Expect no match 
#    bb 
#No match

#/(?|(aaa)|(b))/
#    xaaa
# 0: aaa
# 1: aaa
#    xbc 
# 0: b
# 1: b

#/(?|(?'a'aaa)|(?'a'b))\k'a'/
#    aaaaaa
# 0: aaaaaa
# 1: aaa
#    bb 
# 0: bb
# 1: b

#/(?|(?'a'aaa)|(?'a'b))(?'a'cccc)\k'a'/dupnames
#    aaaccccaaa
# 0: aaaccccaaa
# 1: aaa
# 2: cccc
#    bccccb 
# 0: bccccb
# 1: b
# 2: cccc

# End of testinput1 

# these cause backreferences to try to jump into an If block and fail
#/<a\s+href(?>\s*)=(?>\s*)        # find <a href=
# (["'])?                         # find single or double quote
# (?(1) (.*?)\1 | (\S+))          # if quote found, match up to next matching
#                                 # quote, otherwise match up to next space
#/isx
#    <a href=abcd xyz
# 0: <a href=abcd
# 1: <unset>
# 2: <unset>
# 3: abcd
#    <a href=\"abcd xyz pqr\" cats
# 0: <a href="abcd xyz pqr"
# 1: "
# 2: abcd xyz pqr
#    <a href       =       \'abcd xyz pqr\' cats
# 0: <a href       =       'abcd xyz pqr'
# 1: '
# 2: abcd xyz pqr

#/<a[\s]+href[\s]*=[\s]*          # find <a href=
# ([\"\'])?                       # find single or double quote
# (?(1) (.*?)\1 | ([^\s]+))       # if quote found, match up to next matching
#                                 # quote, otherwise match up to next space
#/isx
#    <a href=abcd xyz
# 0: <a href=abcd
# 1: <unset>
# 2: <unset>
# 3: abcd
#    <a href=\"abcd xyz pqr\" cats
# 0: <a href="abcd xyz pqr"
# 1: "
# 2: abcd xyz pqr
#    <a href=\'abcd xyz pqr\' cats
# 0: <a href='abcd xyz pqr'
# 1: '
# 2: abcd xyz pqr

#/<a\s+href\s*=\s*                # find <a href=
# (["'])?                         # find single or double quote
# (?(1) (.*?)\1 | (\S+))          # if quote found, match up to next matching
#                                 # quote, otherwise match up to next space
#/isx
#    <a href=abcd xyz
# 0: <a href=abcd
# 1: <unset>
# 2: <unset>
# 3: abcd
#    <a href=\"abcd xyz pqr\" cats
# 0: <a href="abcd xyz pqr"
# 1: "
# 2: abcd xyz pqr
#    <a href       =       \'abcd xyz pqr\' cats
# 0: <a href       =       'abcd xyz pqr'
# 1: '
# 2: abcd xyz pqr