regex

Brain/regex.md

@@ -4,8 +4,12 @@ Read [Syntax](https://github.com/google/re2/wiki/Syntax).
 
 Read [Golang-Regex-Tutorial](https://github.com/StefanSchroeder/Golang-Regex-Tutorial).
 
+Play with [Regex101](https://regex101.com/).
+
+## Basic
+
 | regex        | meaning                                   |
-| -------- | ----------------------------------------- |
+| ------------ | ----------------------------------------- |
 | `.`          | any character, default not including `\n` |
 | `[xy]`       | `x` or `y` character                      |
 | `[^xy]`      | not `x` and `y` character                 |
@@ -21,9 +25,6 @@ Read [Golang-Regex-Tutorial](https://github.com/StefanSchroeder/Golang-Regex-Tut
 | `\D`         | not digits                                |
 | `\s`         | whitespace                                |
 | `\S`         | not whitespace                            |
-
-| advanced regex | meaning                             |
-| -------------- | ----------------------------------- |
 | `(foo)`      | numbered capturing group (submatch)       |
 | `(?:foo)`    | non capturing group                       |
 | `(?:x`\|`y)` | `x` or `y` expression wrap in `()`        |
@@ -33,3 +34,23 @@ Read [Golang-Regex-Tutorial](https://github.com/StefanSchroeder/Golang-Regex-Tut
 | ---- | ---------------- |
 | `i`  | case-insensitive |
 | `s`  | `.` match `\n`   |
+
+## Example
+
+```regex
+(?i)hello\sfoo
+
+match: Hello Foo
+match: heLLo fOO
+```
+
+```regex
+hello\s(.+)
+
+match: hello foo
+group 1: foo
+
+
+match: hello bar
+group 1: bar
+```