merge prs

5-regular-expressions/20-regexp-unicode/article.md

@@ -1,5 +1,5 @@
 
-# Unicode: flag "u", character properties "\\p"
+# Unicode: flag "u"
 
 The unicode flag `/.../u` enables the correct support of surrogate pairs.
 
@@ -87,81 +87,3 @@ Using the `u` flag makes it work right:
 ```js run
 alert( '𝒴'.match(/[𝒳-𝒵]/u) ); // 𝒴
 ```
-
-## Unicode character properies
-
-[Unicode](https://en.wikipedia.org/wiki/Unicode), the encoding format used by Javascript strings, has a lot of properties for different characters (or, technically, code points). They describe which "categories" character belongs to, and a variety of technical details.
-
-In regular expressions these can be set by `\p{…}`. And there must be flag `'u'`.
-
-For instance, `\p{Letter}` denotes a letter in any of language. We can also use `\p{L}`, as `L` is an alias of `Letter`, there are shorter aliases for almost every property.
-
-Here's the main tree of properties:
-
-- Letter `L`:
-  - lowercase `Ll`, modifier `Lm`, titlecase `Lt`, uppercase `Lu`, other `Lo`
-- Number `N`:
-  - decimal digit `Nd`, letter number `Nl`, other `No`:
-- Punctuation `P`:
-  - connector `Pc`, dash `Pd`, initial quote `Pi`, final quote `Pf`, open `Ps`, close `Pe`, other `Po`
-- Mark `M` (accents etc):
-  - spacing combining `Mc`, enclosing `Me`, non-spacing `Mn`
-- Symbol `S`:
-  - currency `Sc`, modifier `Sk`, math `Sm`, other `So`
-- Separator `Z`:
-  - line `Zl`, paragraph `Zp`, space `Zs`
-- Other `C`:
-  - control `Cc`, format `Cf`, not assigned `Cn`, private use `Co`, surrogate `Cs`.
-
-```smart header="More information"
-Interested to see which characters belong to a property? There's a tool at <http://cldr.unicode.org/unicode-utilities/list-unicodeset> for that.
-
-You could also explore properties at [Character Property Index](http://unicode.org/cldr/utility/properties.jsp).
-
-For the full Unicode Character Database in text format (along with all properties), see <https://www.unicode.org/Public/UCD/latest/ucd/>.
-```
-
-There are also other derived categories, like:
-- `Alphabetic` (`Alpha`), includes Letters `L`, plus letter numbers `Nl` (e.g. roman numbers Ⅻ), plus some other symbols `Other_Alphabetic` (`OAltpa`).
-- `Hex_Digit` includes hexadimal digits: `0-9`, `a-f`.
-- ...Unicode is a big beast, it includes a lot of properties.
-
-For instance, let's look for a 6-digit hex number:
-
-```js run
-let reg = /\p{Hex_Digit}{6}/u; // flag 'u' is requireds
-
-alert("color: #123ABC".match(reg)); // 123ABC
-```
-
-There are also properties with a value. For instance, Unicode "Script" (a writing system) can be Cyrillic, Greek, Arabic, Han (Chinese) etc, the [list is long]("https://en.wikipedia.org/wiki/Script_(Unicode)").
-
-To search for certain scripts, we should supply `Script=<value>`, e.g. to search for cyrillic letters: `\p{sc=Cyrillic}`, for Chinese glyphs: `\p{sc=Han}`, etc.
-
-### Universal \w
-
-Let's make a "universal" regexp for `pattern:\w`, for any language. That task has a standard solution in many programming languages with unicode-aware regexps, e.g. Perl.
-
-```
-/[\p{Alphabetic}\p{Mark}\p{Decimal_Number}\p{Connector_Punctuation}\p{Join_Control}]/u
-```
-
-Let's decipher. Remember, `pattern:\w` is actually the same as `pattern:[a-zA-Z0-9_]`.
-
-So the character set includes:
-
-- `Alphabetic` for letters,
-- `Mark` for accents, as in Unicode accents may be represented by separate code points,
-- `Decimal_Number` for numbers,
-- `Connector_Punctuation` for the `'_'` character and alike,
-- `Join_Control` -– two special code points with hex codes `200c` and `200d`, used in ligatures e.g. in arabic.
-
-Or, if we replace long names with aliases (a list of aliases [here](https://www.unicode.org/Public/UCD/latest/ucd/PropertyValueAliases.txt)):
-
-```js run
-let regexp = /([\p{Alpha}\p{M}\p{Nd}\p{Pc}\p{Join_C}]+)/gu;
-
-let str = `Hello Привет 你好 123_456`;
-
-alert( str.match(regexp) ); // Hello,Привет,你好,123_456
-```