 
 [ ] [ "(\\$[\\p{XDigit}]|[\\p{Digit}])" <regexp> drop ] unit-test
 
-! Comment
+! Comment inside a regular expression
 [ t ] [ "ac" "a(?#boo)c" <regexp> matches? ] unit-test
 
 [ ] [ "USING: regexp kernel ; R' -{3}[+]{1,6}(?:!!)?\\s' drop" eval ] unit-test

! [ t ] [ "fxxbar" "(?!foo).{3}bar" <regexp> matches? ] unit-test
! [ f ] [ "foobar" "(?!foo).{3}bar" <regexp> matches? ] unit-test

[ 3 ] [ "foobar" "foo(?=bar)" <regexp> match-head ] unit-test
[ f ] [ "foobxr" "foo(?=bar)" <regexp> match-head ] unit-test

! [ f ] [ "foobxr" "foo\\z" <regexp> match-head ] unit-test
! [ 3 ] [ "foo" "foo\\z" <regexp> match-head ] unit-test



! "a(?<=b)" <regexp> "caba" over first-match

! capture group 1: "aaaa"  2: ""
! "aaaa" "(a*)(a*)" <regexp> match*
! "aaaa" "(a*)(a+)" <regexp> match*
