"?" "abc" "()" "[]" "abc|def" "abc|def|ghi" "^xxx$" "ab\\b\\d\\bcd" "\\w|\\d" "a*?" "abc+" "abc+?" "xyz?" "xyz??" "xyz{0,1}" "xyz{0,1}?" "xyz{93}" "xyz{1,32}" "xyz{1,32}?" "xyz{1,}" "xyz{1,}?" "a\\fb\\nc\\rd\\te\\vf" "a\\nb\\bc" "(?:foo)" "(?: foo )" "foo|(bar|baz)|quux" "foo(?=bar)baz" "foo(?!bar)baz" "foo(?<=bar)baz" "foo(?)" "(?.)" "(?.)\\k"