+^(a(??{"(?!)"})|(a)(?{1}))b ab y $2 a # [ID 20010811.006]
+ab(?i)cd AbCd n - - # [ID 20010809.023]
+ab(?i)cd abCd y - -
+(A|B)*(?(1)(CD)|(CD)) CD y $2-$3 -CD
+(A|B)*(?(1)(CD)|(CD)) ABCD y $2-$3 CD-
+(A|B)*?(?(1)(CD)|(CD)) CD y $2-$3 -CD # [ID 20010803.016]
+(A|B)*?(?(1)(CD)|(CD)) ABCD y $2-$3 CD-
+'^(o)(?!.*\1)'i Oo n - -
+(.*)\d+\1 abc12bc y $1 bc
+(?m:(foo\s*$)) foo\n bar y $1 foo
+(.*)c abcd y $1 ab
+(.*)(?=c) abcd y $1 ab
+(.*)(?=c)c abcd yB $1 ab
+(.*)(?=b|c) abcd y $1 ab
+(.*)(?=b|c)c abcd y $1 ab
+(.*)(?=c|b) abcd y $1 ab
+(.*)(?=c|b)c abcd y $1 ab
+(.*)(?=[bc]) abcd y $1 ab
+(.*)(?=[bc])c abcd yB $1 ab
+(.*)(?<=b) abcd y $1 ab
+(.*)(?<=b)c abcd y $1 ab
+(.*)(?<=b|c) abcd y $1 abc
+(.*)(?<=b|c)c abcd y $1 ab
+(.*)(?<=c|b) abcd y $1 abc
+(.*)(?<=c|b)c abcd y $1 ab
+(.*)(?<=[bc]) abcd y $1 abc
+(.*)(?<=[bc])c abcd y $1 ab
+(.*?)c abcd y $1 ab
+(.*?)(?=c) abcd y $1 ab
+(.*?)(?=c)c abcd yB $1 ab
+(.*?)(?=b|c) abcd y $1 a
+(.*?)(?=b|c)c abcd y $1 ab
+(.*?)(?=c|b) abcd y $1 a
+(.*?)(?=c|b)c abcd y $1 ab
+(.*?)(?=[bc]) abcd y $1 a
+(.*?)(?=[bc])c abcd yB $1 ab
+(.*?)(?<=b) abcd y $1 ab
+(.*?)(?<=b)c abcd y $1 ab
+(.*?)(?<=b|c) abcd y $1 ab
+(.*?)(?<=b|c)c abcd y $1 ab
+(.*?)(?<=c|b) abcd y $1 ab
+(.*?)(?<=c|b)c abcd y $1 ab
+(.*?)(?<=[bc]) abcd y $1 ab
+(.*?)(?<=[bc])c abcd y $1 ab
+2(]*)?$\1 2 y $& 2
+(??{}) x y - -
+a(b)?? abc y <$1> <> # undef [perl #16773]
+(\d{1,3}\.){3,} 128.134.142.8 y <$1> <142.> # [perl #18019]
+^.{3,4}(.+)\1\z foobarbar y $1 bar # 16 tests for [perl #23171]
+^(?:f|o|b){3,4}(.+)\1\z foobarbar y $1 bar
+^.{3,4}((?:b|a|r)+)\1\z foobarbar y $1 bar
+^(?:f|o|b){3,4}((?:b|a|r)+)\1\z foobarbar y $1 bar
+^.{3,4}(.+?)\1\z foobarbar y $1 bar
+^(?:f|o|b){3,4}(.+?)\1\z foobarbar y $1 bar
+^.{3,4}((?:b|a|r)+?)\1\z foobarbar y $1 bar
+^(?:f|o|b){3,4}((?:b|a|r)+?)\1\z foobarbar y $1 bar
+^.{2,3}?(.+)\1\z foobarbar y $1 bar
+^(?:f|o|b){2,3}?(.+)\1\z foobarbar y $1 bar
+^.{2,3}?((?:b|a|r)+)\1\z foobarbar y $1 bar
+^(?:f|o|b){2,3}?((?:b|a|r)+)\1\z foobarbar y $1 bar
+^.{2,3}?(.+?)\1\z foobarbar y $1 bar
+^(?:f|o|b){2,3}?(.+?)\1\z foobarbar y $1 bar
+^.{2,3}?((?:b|a|r)+?)\1\z foobarbar y $1 bar
+^(?:f|o|b){2,3}?((?:b|a|r)+?)\1\z foobarbar y $1 bar
+.*a(?!(b|cd)*e).*f ......abef n - - # [perl #23030]
+x(?# x c - Sequence (?#... not terminated
+:x(?#: x c - Sequence (?#... not terminated
+(WORDS|WORD)S WORDS y $1 WORD
+(X.|WORDS|X.|WORD)S WORDS y $1 WORD
+(WORDS|WORLD|WORD)S WORDS y $1 WORD
+(X.|WORDS|WORD|Y.)S WORDS y $1 WORD
+(foo|fool|x.|money|parted)$ fool y $1 fool
+(x.|foo|fool|x.|money|parted|y.)$ fool y $1 fool
+(foo|fool|money|parted)$ fool y $1 fool
+(foo|fool|x.|money|parted)$ fools n - -
+(x.|foo|fool|x.|money|parted|y.)$ fools n - -
+(foo|fool|money|parted)$ fools n - -
+(a|aa|aaa||aaaa|aaaaa|aaaaaa)(b|c) aaaaaaaaaaaaaaab y $1$2 aaaaaab
+(a|aa|aaa||aaaa|aaaaa|aaaaaa)(??{$1&&""})(b|c) aaaaaaaaaaaaaaab y $1$2 aaaaaab
+(a|aa|aaa|aaaa|aaaaa|aaaaaa)(??{$1&&"foo"})(b|c) aaaaaaaaaaaaaaab n - -
+^(a*?)(?!(aa|aaaa)*$) aaaaaaaaaaaaaaaaaaaa y $1 a # [perl #34195]
+^(a*?)(?!(aa|aaaa)*$)(?=a\z) aaaaaaaa y $1 aaaaaaa
+^(.)\s+.$(?(1)) A B y $1 A # [perl #37688]
+(?:r?)*?r|(.{2,4}) abcde y $1 abcd
+(?!)+?|(.{2,4}) abcde y $1 abcd
+^(a*?)(?!(a{6}|a{5})*$) aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa y $+[1] 12 # super-linear cache bug may return 18
+^((?>(?:aa)?b)?) aab y $1 aab
+^((?:aa)*)(?:X+((?:\d+|-)(?:X+(.+))?))?$ aaaaX5 y $1 aaaa
+X(A|B||C|D)Y XXXYYY y $& XY # Trie w/ NOTHING
+(?i:X([A]|[B]|y[Y]y|[D]|)Y) XXXYYYB y $& XY # Trie w/ NOTHING
+^([a]{1})*$ aa y $1 a
+a(?!b(?!c))(..) abababc y $1 bc # test nested negatives
+a(?!b(?=a))(..) abababc y $1 bc # test nested lookaheads
+a(?!b(?!c(?!d(?!e))))...(.) abxabcdxabcde y $1 e
+X(?!b+(?!(c+)*(?!(c+)*d))).*X aXbbbbbbbcccccccccccccaaaX y - -
+^(XXXXXXXXXX|YYYYYYYYYY|Z.Q*X|Z[TE]Q*P): ZEQQQQQQQQQQQQQQQQQQP: y $1 ZEQQQQQQQQQQQQQQQQQQP
+^(XXXXXXXXXX|YYYYYYYYYY|Z.Q*X|Z[TE]Q*P): ZEQQQX: y $1 ZEQQQX
+^([TUV]+|XXXXXXXXXX|YYYYYYYYYY|Z.Q*X|Z[TE]Q*P): ZEQQQQQQQQQQQQQQQQQQP: y $1 ZEQQQQQQQQQQQQQQQQQQP
+^([TUV]+|XXXXXXXXXX|YYYYYYYYYY|Z.Q*X|Z[TE]Q*P): ZEQQQX: y $1 ZEQQQX
+^([TUV]+|XXXXXXXXXX|YYYYYYYYYY|Z.Q*X|Z[TE]Q*P|[MKJ]): ZEQQQQQQQQQQQQQQQQQQP: y $1 ZEQQQQQQQQQQQQQQQQQQP
+^([TUV]+|XXXXXXXXXX|YYYYYYYYYY|Z.Q*X|Z[TE]Q*P|[MKJ]): ZEQQQX: y $1 ZEQQQX
+^(XXX|YYY|Z.Q*X|Z[TE]Q*P): ZEQQQQQQQQQQQQQQQQQQP: y $1 ZEQQQQQQQQQQQQQQQQQQP
+^(XXX|YYY|Z.Q*X|Z[TE]Q*P): ZEQQQX: y $1 ZEQQQX
+^([TUV]+|XXX|YYY|Z.Q*X|Z[TE]Q*P): ZEQQQQQQQQQQQQQQQQQQP: y $1 ZEQQQQQQQQQQQQQQQQQQP
+^([TUV]+|XXX|YYY|Z.Q*X|Z[TE]Q*P): ZEQQQX: y $1 ZEQQQX
+^([TUV]+|XXX|YYY|Z.Q*X|Z[TE]Q*P|[MKJ]): ZEQQQQQQQQQQQQQQQQQQP: y $1 ZEQQQQQQQQQQQQQQQQQQP
+^([TUV]+|XXX|YYY|Z.Q*X|Z[TE]Q*P|[MKJ]): ZEQQQX: y $1 ZEQQQX
+X(?:ABCF[cC]x*|ABCD|ABCF):(?:DIT|DID|DIM) XABCFCxxxxxxxxxx:DIM y $& XABCFCxxxxxxxxxx:DIM
+(((ABCD|ABCE|ABCF)))(A|B|C[xy]*): ABCFCxxxxxxxxxx:DIM y $& ABCFCxxxxxxxxxx:
+(?=foo) foo y pos 0
+(?=foo) XfooY y pos 1
+.*(?=foo) XfooY y pos 1
+(?<=foo) foo y pos 3
+(?<=foo) XfooY y pos 4
+.*(?<=foo) foo y pos 3
+.*(?<=foo) XfooY y pos 4
+(?<=foo)Y XfooY y pos 5
+o(?<=foo)Y ..XfooY.. y pos 7
+X(?=foo)f ..XfooY.. y pos 4
+X(?=foo) ..XfooY.. y pos 3
+X(?<=foo.)[YZ] ..XfooXY.. y pos 8
+(?=XY*foo) Xfoo y pos 0
+^(?=XY*foo) Xfoo y pos 0
+^(??{"a+"})a aa y $& aa
+^(?:(??{"a+"})|b)a aa y $& aa
+^(??{chr 0x100}).$ \x{100}\x{100} y $& \x{100}\x{100}
+^(??{q(\x{100})}). \x{100}\x{100} y $& \x{100}\x{100}
+^(??{q(.+)})\x{100} \x{100}\x{100} y $& \x{100}\x{100}
+^(??{q(.)})\x{100} \x{100}\x{100} y $& \x{100}\x{100}
+^(??{chr 0x100})\xbb \x{100}\x{bb} y $& \x{100}\x{bb}
+^(.)(??{"(.)(.)"})(.)$ abcd y $1-$2 a-d
+^(.)(??{"(bz+|.)(.)"})(.)$ abcd y $1-$2 a-d
+^(.)((??{"(.)(cz+)"})|.) abcd y $1-$2 a-b
+^a(?>(??{q(b)}))(??{q(c)})d abcd y - -
+^x(??{""})+$ x y $& x
+^(<(?:[^<>]+|(?3)|(?1))*>)()(!>!>!>)$ <<!>!>!>><>>!>!>!> y $1 <<!>!>!>><>>
+^(<(?:[^<>]+|(?1))*>)$ <<><<<><>>>> y $1 <<><<<><>>>>
+((?2)*)([fF]o+) fooFoFoo y $1-$2 fooFo-Foo
+(<(?:[^<>]+|(?R))*>) <<><<<><>>>> y $1 <<><<<><>>>>
+(?<n>foo|bar|baz) snofooewa y $1 foo
+(?<n>foo|bar|baz) snofooewa y $+{n} foo
+(?<n>foo|bar|baz)(?<m>[ew]+) snofooewa y $+{n} foo
+(?<n>foo|bar|baz)(?<m>[ew]+) snofooewa y $+{m} ew
+(?<n>foo)|(?<n>bar)|(?<n>baz) snofooewa y $+{n} foo
+(?<n>foo)(??{ $+{n} }) snofooefoofoowaa y $+{n} foo
+(?P<n>foo|bar|baz) snofooewa y $1 foo
+(?P<n>foo|bar|baz) snofooewa y $+{n} foo
+(?P<n>foo|bar|baz)(?P<m>[ew]+) snofooewa y $+{n} foo
+(?P<n>foo|bar|baz)(?P<m>[ew]+) snofooewa y $+{m} ew
+(?P<n>foo)|(?P<n>bar)|(?P<n>baz) snofooewa y $+{n} foo
+(?P<n>foo)(??{ $+{n} }) snofooefoofoowaa y $+{n} foo
+(?P<=n>foo|bar|baz) snofooewa c - Sequence (?P<=...) not recognized
+(?P<!n>foo|bar|baz) snofooewa c - Sequence (?P<!...) not recognized
+(?PX<n>foo|bar|baz) snofooewa c - Sequence (?PX<...) not recognized
+/(?'n'foo|bar|baz)/ snofooewa y $1 foo
+/(?'n'foo|bar|baz)/ snofooewa y $+{n} foo
+/(?'n'foo|bar|baz)(?'m'[ew]+)/ snofooewa y $+{n} foo
+/(?'n'foo|bar|baz)(?'m'[ew]+)/ snofooewa y $+{m} ew
+/(?'n'foo)|(?'n'bar)|(?<n>baz)/ snobazewa y $+{n} baz
+/(?'n'foo)(??{ $+{n} })/ snofooefoofoowaa y $+{n} foo
+/(?'n'foo)\k<n>/ ..foofoo.. y $1 foo
+/(?'n'foo)\k<n>/ ..foofoo.. y $+{n} foo
+/(?<n>foo)\k'n'/ ..foofoo.. y $1 foo
+/(?<n>foo)\k'n'/ ..foofoo.. y $+{n} foo
+/(?:(?<n>foo)|(?<n>bar))\k<n>/ ..barbar.. y $+{n} bar
+/^(?'main'<(?:[^<>]+|(?&crap)|(?&main))*>)(?'empty')(?'crap'!>!>!>)$/ <<!>!>!>><>>!>!>!> y $+{main} <<!>!>!>><>>
+/^(?'main'<(?:[^<>]+|(?&main))*>)$/ <<><<<><>>>> y $1 <<><<<><>>>>
+/(?'first'(?&second)*)(?'second'[fF]o+)/ fooFoFoo y $+{first}-$+{second} fooFo-Foo
+(?<A>foo)?(?(<A>)bar|nada) foobar y $+{A} foo
+(?<A>foo)?(?(<A>)bar|nada) foo-barnada y $& nada
+(?<A>foo)?(?(1)bar|nada) foo-barnada y $& nada
+(?<A>foo(?(R)bar))?(?1) foofoobar y $1 foo
+(?<A>foo(?(R)bar))?(?1) foofoobar y $& foofoobar
+(x)(?<A>foo(?(R&A)bar))?(?&A) xfoofoobar y $2 foo
+(x)(?<A>foo(?(R&A)bar))?(?&A) xfoofoobar y $& xfoofoobar
+(x)(?<A>foo(?(R2)bar))?(?&A) xfoofoobar y $2 foo
+(x)(?<A>foo(?(R2)bar))?(?&A) xfoofoobar y $& xfoofoobar
+(?1)(?(DEFINE)(blah)) blah y $& blah
+/^(?<PAL>(?<CHAR>.)((?&PAL)|.?)\k<CHAR>)$/ madamimadam y $& madamimadam
+/^(?<PAL>(?<CHAR>.)((?&PAL)|.?)\k<CHAR>)$/ madamiamadam n - -
+/(a)?((?1))(fox)/ aafox y $1-$2-$3 a-a-fox
+/(a)*((?1))(fox)/ aafox y $1-$2-$3 a-a-fox
+/(a)+((?1))(fox)/ aafox y $1-$2-$3 a-a-fox
+/(a){1,100}((?1))(fox)/ aafox y $1-$2-$3 a-a-fox
+/(a){0,100}((?1))(fox)/ aafox y $1-$2-$3 a-a-fox
+/(ab)?((?1))(fox)/ ababfox y $1-$2-$3 ab-ab-fox
+/(ab)*((?1))(fox)/ ababfox y $1-$2-$3 ab-ab-fox
+/(ab)+((?1))(fox)/ ababfox y $1-$2-$3 ab-ab-fox
+/(ab){1,100}((?1))(fox)/ ababfox y $1-$2-$3 ab-ab-fox
+/(ab){0,100}((?1))(fox)/ ababfox y $1-$2-$3 ab-ab-fox
+# possessive captures
+a++a aaaaa n - -
+a*+a aaaaa n - -
+a{1,5}+a aaaaa n - -
+a?+a ab n - -
+a++b aaaaab y $& aaaaab
+a*+b aaaaab y $& aaaaab
+a{1,5}+b aaaaab y $& aaaaab
+a?+b ab y $& ab
+fooa++a fooaaaaa n - -
+fooa*+a fooaaaaa n - -
+fooa{1,5}+a fooaaaaa n - -
+fooa?+a fooab n - -
+fooa++b fooaaaaab y $& fooaaaaab
+fooa*+b fooaaaaab y $& fooaaaaab
+fooa{1,5}+b fooaaaaab y $& fooaaaaab
+fooa?+b fooab y $& fooab
+(?:aA)++(?:aA) aAaAaAaAaA n - aAaAaAaAaA
+(aA)++(aA) aAaAaAaAaA n - aAaAaAaAaA
+(aA|bB)++(aA|bB) aAaAbBaAbB n - aAaAbBaAbB
+(?:aA|bB)++(?:aA|bB) aAbBbBbBaA n - aAbBbBbBaA
+(?:aA)*+(?:aA) aAaAaAaAaA n - aAaAaAaAaA
+(aA)*+(aA) aAaAaAaAaA n - aAaAaAaAaA
+(aA|bB)*+(aA|bB) aAaAbBaAaA n - aAaAbBaAaA
+(?:aA|bB)*+(?:aA|bB) aAaAaAbBaA n - aAaAaAbBaA
+(?:aA){1,5}+(?:aA) aAaAaAaAaA n - aAaAaAaAaA
+(aA){1,5}+(aA) aAaAaAaAaA n - aAaAaAaAaA
+(aA|bB){1,5}+(aA|bB) aAaAbBaAaA n - aAaAbBaAaA
+(?:aA|bB){1,5}+(?:aA|bB) bBbBbBbBbB n - bBbBbBbBbB
+(?:aA)?+(?:aA) aAb n - aAb
+(aA)?+(aA) aAb n - aAb
+(aA|bB)?+(aA|bB) bBb n - bBb
+(?:aA|bB)?+(?:aA|bB) aAb n - aAb
+(?:aA)++b aAaAaAaAaAb y $& aAaAaAaAaAb
+(aA)++b aAaAaAaAaAb y $& aAaAaAaAaAb
+(aA|bB)++b aAbBaAaAbBb y $& aAbBaAaAbBb
+(?:aA|bB)++b aAbBbBaAaAb y $& aAbBbBaAaAb
+(?:aA)*+b aAaAaAaAaAb y $& aAaAaAaAaAb
+(aA)*+b aAaAaAaAaAb y $& aAaAaAaAaAb
+(aA|bB)*+b bBbBbBbBbBb y $& bBbBbBbBbBb
+(?:aA|bB)*+b bBaAbBbBaAb y $& bBaAbBbBaAb
+(?:aA){1,5}+b aAaAaAaAaAb y $& aAaAaAaAaAb
+(aA){1,5}+b aAaAaAaAaAb y $& aAaAaAaAaAb
+(aA|bB){1,5}+b bBaAbBaAbBb y $& bBaAbBaAbBb
+(?:aA|bB){1,5}+b aAbBaAbBbBb y $& aAbBaAbBbBb
+(?:aA)?+b aAb y $& aAb
+(aA)?+b aAb y $& aAb
+(aA|bB)?+b bBb y $& bBb
+(?:aA|bB)?+b bBb y $& bBb
+foo(?:aA)++(?:aA) fooaAaAaAaAaA n - fooaAaAaAaAaA
+foo(aA)++(aA) fooaAaAaAaAaA n - fooaAaAaAaAaA
+foo(aA|bB)++(aA|bB) foobBbBbBaAaA n - foobBbBbBaAaA
+foo(?:aA|bB)++(?:aA|bB) fooaAaAaAaAaA n - fooaAaAaAaAaA
+foo(?:aA)*+(?:aA) fooaAaAaAaAaA n - fooaAaAaAaAaA
+foo(aA)*+(aA) fooaAaAaAaAaA n - fooaAaAaAaAaA
+foo(aA|bB)*+(aA|bB) foobBaAbBaAaA n - foobBaAbBaAaA
+foo(?:aA|bB)*+(?:aA|bB) fooaAaAbBbBaA n - fooaAaAbBbBaA
+foo(?:aA){1,5}+(?:aA) fooaAaAaAaAaA n - fooaAaAaAaAaA
+foo(aA){1,5}+(aA) fooaAaAaAaAaA n - fooaAaAaAaAaA
+foo(aA|bB){1,5}+(aA|bB) fooaAbBbBaAaA n - fooaAbBbBaAaA
+foo(?:aA|bB){1,5}+(?:aA|bB) fooaAbBbBaAbB n - fooaAbBbBaAbB
+foo(?:aA)?+(?:aA) fooaAb n - fooaAb
+foo(aA)?+(aA) fooaAb n - fooaAb
+foo(aA|bB)?+(aA|bB) foobBb n - foobBb
+foo(?:aA|bB)?+(?:aA|bB) fooaAb n - fooaAb
+foo(?:aA)++b fooaAaAaAaAaAb y $& fooaAaAaAaAaAb
+foo(aA)++b fooaAaAaAaAaAb y $& fooaAaAaAaAaAb
+foo(aA|bB)++b foobBaAbBaAbBb y $& foobBaAbBaAbBb
+foo(?:aA|bB)++b fooaAaAbBaAaAb y $& fooaAaAbBaAaAb
+foo(?:aA)*+b fooaAaAaAaAaAb y $& fooaAaAaAaAaAb
+foo(aA)*+b fooaAaAaAaAaAb y $& fooaAaAaAaAaAb
+foo(aA|bB)*+b foobBbBaAaAaAb y $& foobBbBaAaAaAb
+foo(?:aA|bB)*+b foobBaAaAbBaAb y $& foobBaAaAbBaAb
+foo(?:aA){1,5}+b fooaAaAaAaAaAb y $& fooaAaAaAaAaAb
+foo(aA){1,5}+b fooaAaAaAaAaAb y $& fooaAaAaAaAaAb
+foo(aA|bB){1,5}+b foobBaAaAaAaAb y $& foobBaAaAaAaAb
+foo(?:aA|bB){1,5}+b fooaAbBaAbBbBb y $& fooaAbBaAbBbBb
+foo(?:aA)?+b fooaAb y $& fooaAb
+foo(aA)?+b fooaAb y $& fooaAb
+foo(aA|bB)?+b foobBb y $& foobBb
+foo(?:aA|bB)?+b foobBb y $& foobBb
+
+([^()]++|\([^()]*\))+ ((abc(ade)ufh()()x y $& abc(ade)ufh()()x
+round\(([^()]++)\) _I(round(xs * sz),1) y $1 xs * sz
+
+(foo[1x]|bar[2x]|baz[3x])+y foo1bar2baz3y y $1 baz3
+(foo[1x]|bar[2x]|baz[3x])+y foo1bar2baz3y y $& foo1bar2baz3y
+(foo[1x]|bar[2x]|baz[3x])*y foo1bar2baz3y y $1 baz3
+(foo[1x]|bar[2x]|baz[3x])*y foo1bar2baz3y y $& foo1bar2baz3y
+
+([yX].|WORDS|[yX].|WORD)S WORDS y $1 WORD
+(WORDS|WORLD|WORD)S WORDS y $1 WORD
+([yX].|WORDS|WORD|[xY].)S WORDS y $1 WORD
+(foo|fool|[zx].|money|parted)$ fool y $1 fool
+([zx].|foo|fool|[zq].|money|parted|[yx].)$ fool y $1 fool
+(foo|fool|[zx].|money|parted)$ fools n - -
+([zx].|foo|fool|[qx].|money|parted|[py].)$ fools n - -
+
+([yX].|WORDS|[yX].|WORD)+S WORDS y $1 WORD
+(WORDS|WORLD|WORD)+S WORDS y $1 WORD
+([yX].|WORDS|WORD|[xY].)+S WORDS y $1 WORD
+(foo|fool|[zx].|money|parted)+$ fool y $1 fool
+([zx].|foo|fool|[zq].|money|parted|[yx].)+$ fool y $1 fool
+(foo|fool|[zx].|money|parted)+$ fools n - -
+([zx].|foo|fool|[qx].|money|parted|[py].)+$ fools n - -
+
+(x|y|z[QW])+(longish|loquatious|excessive|overblown[QW])+ xyzQzWlongishoverblownW y $1-$2 zW-overblownW
+(x|y|z[QW])*(longish|loquatious|excessive|overblown[QW])* xyzQzWlongishoverblownW y $1-$2 zW-overblownW
+(x|y|z[QW]){1,5}(longish|loquatious|excessive|overblown[QW]){1,5} xyzQzWlongishoverblownW y $1-$2 zW-overblownW
+
+(x|y|z[QW])++(longish|loquatious|excessive|overblown[QW])++ xyzQzWlongishoverblownW y $1-$2 zW-overblownW
+(x|y|z[QW])*+(longish|loquatious|excessive|overblown[QW])*+ xyzQzWlongishoverblownW y $1-$2 zW-overblownW
+(x|y|z[QW]){1,5}+(longish|loquatious|excessive|overblown[QW]){1,5}+ xyzQzWlongishoverblownW y $1-$2 zW-overblownW
+
+a*(?!) aaaab n - -
+a*(*FAIL) aaaab n - -
+a*(*F) aaaab n - -
+
+(A(A|B(*ACCEPT)|C)D)(E) AB y $1 AB
+(A(A|B(*ACCEPT)|C)D)(E) ACDE y $1$2$3 ACDCE
+
+(a)(?:(?-1)|(?+1))(b) aab y $&-$1-$2 aab-a-b
+(a)(?:(?-1)|(?+1))(b) abb y $1-$2 a-b
+(a)(?:(?-1)|(?+1))(b) acb n - -
+
+(foo)(\g-2) foofoo y $1-$2 foo-foo
+(foo)(\g-2)(foo)(\g-2) foofoofoofoo y $1-$2-$3-$4 foo-foo-foo-foo
+(([abc]+) \g-1)(([abc]+) \g{-1}) abc abccba cba y $2-$4 abc-cba
+(a)(b)(c)\g1\g2\g3 abcabc y $1$2$3 abc
+
+# \k<n> preceded by a literal
+/(?'n'foo) \k<n>/ ..foo foo.. y $1 foo
+/(?'n'foo) \k<n>/ ..foo foo.. y $+{n} foo
+/(?<n>foo) \k'n'/ ..foo foo.. y $1 foo
+/(?<n>foo) \k'n'/ ..foo foo.. y $+{n} foo
+/(?'a1'foo) \k'a1'/ ..foo foo.. y $+{a1} foo
+/(?<a1>foo) \k<a1>/ ..foo foo.. y $+{a1} foo
+/(?'_'foo) \k'_'/ ..foo foo.. y $+{_} foo
+/(?<_>foo) \k<_>/ ..foo foo.. y $+{_} foo
+/(?'_0_'foo) \k'_0_'/ ..foo foo.. y $+{_0_} foo
+/(?<_0_>foo) \k<_0_>/ ..foo foo.. y $+{_0_} foo
+/(?'0'foo) bar/ ..foo bar.. c - Sequence (?'
+/(?<0>foo) bar/ ..foo bar.. c - Sequence (?<
+/(?'12'foo) bar/ ..foo bar.. c - Sequence (?'
+/(?<12>foo) bar/ ..foo bar.. c - Sequence (?<
+/(?'1a'foo) bar/ ..foo bar.. c - Sequence (?'
+/(?<1a>foo) bar/ ..foo bar.. c - Sequence (?<
+/(?''foo) bar/ ..foo bar.. c - Sequence (?''
+/(?<>foo) bar/ ..foo bar.. c - Sequence (?<>
+/foo \k'n'/ foo foo c - Reference to nonexistent named group
+/foo \k<n>/ foo foo c - Reference to nonexistent named group
+/foo \k'a1'/ foo foo c - Reference to nonexistent named group
+/foo \k<a1>/ foo foo c - Reference to nonexistent named group
+/foo \k'_'/ foo foo c - Reference to nonexistent named group
+/foo \k<_>/ foo foo c - Reference to nonexistent named group
+/foo \k'_0_'/ foo foo c - Reference to nonexistent named group
+/foo \k<_0_>/ foo foo c - Reference to nonexistent named group
+/foo \k'0'/ foo foo c - Sequence \\k'
+/foo \k<0>/ foo foo c - Sequence \\k<
+/foo \k'12'/ foo foo c - Sequence \\k'
+/foo \k<12>/ foo foo c - Sequence \\k<
+/foo \k'1a'/ foo foo c - Sequence \\k'
+/foo \k<1a>/ foo foo c - Sequence \\k<
+/foo \k''/ foo foo c - Sequence \\k'
+/foo \k<>/ foo foo c - Sequence \\k<
+/(?<as>as) (\w+) \k<as> (\w+)/ as easy as pie y $1-$2-$3 as-easy-pie
+
+# \g{...} with a name as the argument
+/(?'n'foo) \g{n}/ ..foo foo.. y $1 foo
+/(?'n'foo) \g{n}/ ..foo foo.. y $+{n} foo
+/(?<n>foo) \g{n}/ ..foo foo.. y $1 foo
+/(?<n>foo) \g{n}/ ..foo foo.. y $+{n} foo
+/(?<as>as) (\w+) \g{as} (\w+)/ as easy as pie y $1-$2-$3 as-easy-pie
+
+# Python style named capture buffer stuff
+/(?P<n>foo)(?P=n)/ ..foofoo.. y $1 foo
+/(?P<n>foo)(?P=n)/ ..foofoo.. y $+{n} foo
+/(?:(?P<n>foo)|(?P<n>bar))(?P=n)/ ..barbar.. y $+{n} bar
+/^(?P<PAL>(?P<CHAR>.)((?P>PAL)|.?)(?P=CHAR))$/ madamimadam y $& madamimadam
+/^(?P<PAL>(?P<CHAR>.)((?P>PAL)|.?)(?P=CHAR))$/ madamiamadam n - -
+/(?P<n>foo) (?P=n)/ ..foo foo.. y $1 foo
+/(?P<n>foo) (?P=n)/ ..foo foo.. y $+{n} foo
+/(?P<as>as) (\w+) (?P=as) (\w+)/ as easy as pie y $1-$2-$3 as-easy-pie
+
+#check that non identifiers as names are treated as the appropriate lookaround
+(?<=bar>)foo bar>foo y $& foo
+(?<!bar>)foo bar>foo n - -
+(?<=bar>ABC)foo bar>ABCfoo y $& foo
+(?<!bar>ABC)foo bar>ABCfoo n - -
+(?<bar>)foo bar>ABCfoo y $& foo
+(?<bar>ABC)foo bar>ABCfoo y $& ABCfoo
+
+(?<=abcd(?<=(aaaabcd))) ..aaaabcd.. y $1 aaaabcd
+(?=xy(?<=(aaxy))) ..aaxy.. y $1 aaxy
+
+X(\w+)(?=\s)|X(\w+) Xab y [$1-$2] [-ab]
+
+#check that branch reset works ok.
+(?|a(.)b|d(.(o).)d|i(.)(.)j)(.) d!o!da y $1-$2-$3 !o!-o-a
+(?|a(.)b|d(.(o).)d|i(.)(.)j)(.) aabc y $1-$2-$3 a--c
+(?|a(.)b|d(.(o).)d|i(.)(.)j)(.) ixyjp y $1-$2-$3 x-y-p
+(?|(?|(a)|(b))|(?|(c)|(d))) a y $1 a
+(?|(?|(a)|(b))|(?|(c)|(d))) b y $1 b
+(?|(?|(a)|(b))|(?|(c)|(d))) c y $1 c
+(?|(?|(a)|(b))|(?|(c)|(d))) d y $1 d
+(.)(?|(.)(.)x|(.)d)(.) abcde y $1-$2-$3-$4-$5- b-c--e--
+#Bug #41492
+(?(DEFINE)(?<A>(?&B)+)(?<B>a))(?&A) a y $& a
+(?(DEFINE)(?<A>(?&B)+)(?<B>a))(?&A) aa y $& aa
+\x{100}?(??{""})xxx xxx y $& xxx
+
+foo(\R)bar foo\r\nbar y $1 \r\n
+foo(\R)bar foo\nbar y $1 \n
+foo(\R)bar foo\rbar y $1 \r
+
+foo(\R+)bar foo\r\n\x{85}\r\n\nbar y $1 \r\n\x{85}\r\n\n
+(\V+)(\R) foo\r\n\x{85}\r\n\nbar y $1-$2 foo-\r\n
+(\R+)(\V) foo\r\n\x{85}\r\n\nbar y $1-$2 \r\n\x{85}\r\n\n-b
+foo(\R)bar foo\x{85}bar y $1 \x{85}
+(\V)(\R) foo\x{85}bar y $1-$2 o-\x{85}
+(\R)(\V) foo\x{85}bar y $1-$2 \x{85}-b
+foo(\R)bar foo\r\nbar y $1 \r\n
+(\V)(\R) foo\r\nbar y $1-$2 o-\r\n
+(\R)(\V) foo\r\nbar y $1-$2 \r\n-b
+foo(\R)bar foo\r\nbar y $1 \r\n
+(\V)(\R) foo\r\nbar y $1-$2 o-\r\n
+(\R)(\V) foo\r\nbar y $1-$2 \r\n-b
+foo(\R)bar foo\rbar y $1 \r
+(\V)(\R) foo\rbar y $1-$2 o-\r
+(\R)(\V) foo\rbar y $1-$2 \r-b
+
+foo(\v+)bar foo\r\n\x{85}\r\n\nbar y $1 \r\n\x{85}\r\n\n
+(\V+)(\v) foo\r\n\x{85}\r\n\nbar y $1-$2 foo-\r
+(\v+)(\V) foo\r\n\x{85}\r\n\nbar y $1-$2 \r\n\x{85}\r\n\n-b
+foo(\v)bar foo\x{85}bar y $1 \x{85}
+(\V)(\v) foo\x{85}bar y $1-$2 o-\x{85}
+(\v)(\V) foo\x{85}bar y $1-$2 \x{85}-b
+foo(\v)bar foo\rbar y $1 \r
+(\V)(\v) foo\rbar y $1-$2 o-\r
+(\v)(\V) foo\rbar y $1-$2 \r-b
+
+
+foo(\h+)bar foo\t\x{A0}bar y $1 \t\x{A0}
+(\H+)(\h) foo\t\x{A0}bar y $1-$2 foo-\t
+(\h+)(\H) foo\t\x{A0}bar y $1-$2 \t\x{A0}-b
+foo(\h)bar foo\x{A0}bar y $1 \x{A0}
+(\H)(\h) foo\x{A0}bar y $1-$2 o-\x{A0}
+(\h)(\H) foo\x{A0}bar y $1-$2 \x{A0}-b
+foo(\h)bar foo\tbar y $1 \t
+(\H)(\h) foo\tbar y $1-$2 o-\t
+(\h)(\H) foo\tbar y $1-$2 \t-b
+
+.*\z foo\n y - -
+^(?:(\d)x)?\d$ 1 y ${\(defined($1)?1:0)} 0
+.*?(?:(\w)|(\w))x abx y $1-$2 b-
+
+0{50} 000000000000000000000000000000000000000000000000000 y - -
+^a?(?=b)b ab B $& ab # Bug #56690
+^a*(?=b)b ab B $& ab # Bug #56690
+/>\d+$ \n/ix >10\n y $& >10
+/>\d+$ \n/ix >1\n y $& >1
+/\d+$ \n/ix >10\n y $& 10
+/>\d\d$ \n/ix >10\n y $& >10
+/>\d+$ \n/x >10\n y $& >10
+
+# Two regressions in 5.8.x (only) introduced by change 30638
+# Simplification of the test failure in XML::LibXML::Simple:
+/^\s*i.*?o\s*$/s io\n io y - -
+# As reported in #59168 by Father Chrysostomos:
+/(.*?)a(?!(a+)b\2c)/ baaabaac y $&-$1 baa-ba
+# [perl #60344] Regex lookbehind failure after an (if)then|else in perl 5.10
+/\A(?(?=db2)db2|\D+)(?<!processed)\.csv\z/xms sql_processed.csv n - -
+/\N{U+0100}/ \x{100} y $& \x{100} # Bug #59328
+[\s][\S] \x{a0}\x{a0} nT - - # TODO Unicode complements should not match same character
+
+# was generating malformed utf8
+'[\x{100}\xff]'i \x{ff} y $& \x{ff}
+
+((??{ "(?:|)" }))\s C\x20 y - -