add extended trim about strings

[olegbaturin]

1. trim() removes only single bytes specified in $characters parameter and can't safely remove multibyte characters.
2. When PCRE modifier u(PCRE_UTF8) is set, strings are treated as UTF-8, so it's a utf8 trim.

Generalized version

public static function trim(string $str, string $pattern = "\pC\pZ"): string
{
    return preg_replace("#^[$pattern]+|[$pattern]+$#u", '', $str);
}

[olegbaturin]

I think need use another name... May be:

* `regexpTrim()` (I like it)

* `pregTrim()`

* `reTrim()`

?

But I not sure. May be trim better name =) Need more opinions.

trim() is well known function name for string trimming. Does the implementation details matter?

[vjik]

In what cases is this necessary?

[olegbaturin]

In what cases is this necessary?

I'm using it to sanitize user input data.

[samdark]

Sanitize it from what exactly? Why exactly this characters set but not, for example, x0c?

[olegbaturin]

Updated method for advanced trimming ascii and utf8 strings

public static function trim(string $str): string
{
    return preg_replace("#^[\pC\pZ]+|[\pC\pZ]+$#u", '', $str);
}

List of unicode whitespace characters https://en.wikipedia.org/wiki/Whitespace_character#Unicode

[vjik]

1. Which is faster: trim() with full symbols list or preg_replace() ?

2. Should this method has name trim or more specific?

[vjik]

I think need use another name... May be:

• regexpTrim() (I like it)
• pregTrim()
• reTrim()

?

But I not sure. May be trim better name =) Need more opinions.

[olegbaturin]

It can be applied to utf8 and ascii strings, not only to utf8.

[vjik]

@olegbaturin Will you undertake to do PR?

[olegbaturin]

What about ltrim()/rtrim()?

[xepozz]

I think need use another name... May be:

* `regexpTrim()` (I like it)

* `pregTrim()`

* `reTrim()`

?
But I not sure. May be trim better name =) Need more opinions.

trim() is well known function name for string trimming. Does the implementation details matter?

The implementations matter when performance is a goal, but otherwise developers may use regular trim, so it's good to have kind of boosted trim

[olegbaturin]

developers may use regular trim

Regular trim can't be used to remove unicode symbols, unfortunately.

[xepozz]

So would you like to implement it?

[xepozz]

I think all trim, ltrim, rtrim can be here.

[vjik]

Done by #109