.[X](.+)+[X][X] bbbbXXXaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa n - -
.[X][X](.+)+[X] bbbbXXXaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa n - -
tt+$ xxxtt y - -
+[a-\w] - c - /[a-\w]/: invalid [] range in regexp
+[\w-z] - c - /[\w-z]/: invalid [] range in regexp
+[0-[:digit:]] - c - /[0-[:digit:]]/: invalid [] range in regexp
+[[:digit:]-9] - c - /[[:digit:]-9]/: invalid [] range in regexp