a	~	a
		ba
		bab
	!~	""
		x
		xxxxx
.	~	x
		xxx
	!~	""			
.a	~	xa
		xxa
		xax
	!~	a
		ax
		""
$	~	x
		""
.$	~	x
		xx
	!~	""
a$	~	a
		ba
		bbba
	!~	ab
		x
		""
^	~	x
		""
		^
^a$	~	a
	!~	xa
		ax
		xax
		""
^a.$	~	ax
		aa
	!~	xa
		aaa
		axy
		""
^$	~	""
	!~	x
		^
^.a	~	xa
		xaa
	!~	a
		""
^.*a	~	a
		xa
		xxxxxxa
	!~	""
^.+a	~	xa
		xxxxxxa
	!~	""
		a
		ax
a*	~	""
		a
		aaaa
		xa
		xxxx
aa*	~	a
		aaa
		xa
	!~	xxxx
		""
\$	~	x$
		$
		$x
		x$x
	!~	""
		x
\.	~	.
	!~	x
		""
xr+y	~	xry
		xrry
		xrrrrrry
	!~	ry
		xy
		xr
xr?y	~	xy
		xry
	!~	xrry
a?b?c?	~	""
		x
^a?b?x	~	x
		ax
		bx
		abx
		xa
	!~	""
		ab
		aba			
[0-9]	~	1
		567
		x0y
	!~	abc
		""
[^0-9]	!~	1
		567
		""
	~	abc
		x0y
x[0-9]+y	~	x0y
		x23y
		x12345y
	!~	0y
		xy
x[0-9]?y	~	xy
		x1y
	!~	x23y
x[[]y	~	x[y
	!~	xy
		x[[]y
		x]y
x[^[]y	~	xay
	!~	x[y
x[-]y	~	x-y
	!~	xy
		x+y
x[^-]y	~	x+y
	!~	x-y
		xy
[0\-9]	~	0
		-
		9
	!~	1
		""
[-1]	~	-
		1
	!~	0
[0-]	~	0
		-
	!~	1
[^-0]	~	x
		^
	!~	-
		0
		""
[^0-]	~	x
		^
	!~	-
		0
		""
x|y	~	x
		y
		xy
	!~	a
		""
^x\|y$	~	x|y
	!~	xy
