Add str_contains() function

[Danil42Russia]

Information

• PHP RFC name: str_contains
• PHP RFC link: https://wiki.php.net/rfc/str_contains
• Issue: PHP 8 #290
• Added a function from a low priority block :)
• Tests written

Example

str_contains("test string", "test"); // true
str_contains("test string", "hello"); // false

[Danil42Russia]

Error text:

Starting php to cpp transpiling...

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Compilation error at stage: Parse file, gen by compiler-core.cpp:277
  lib/polyfills/file2.php:10
    }

Redeclaration of function str_contains(), the previous declaration was in .../builtin-functions/_functions.txt

Compilation terminated due to errors

The error occurs due to the declaration of the str_contains function in file2.php

[Danil42Russia]

Tests don't break anymore!

[quasilyte]

What are the advantages of implementing it as a new functions instead of using already existing strpos?

PHP uses similar approach:
https://github.com/php/php-src/blob/0b6f58d907e7169f7876bbea199967262197fbaa/ext/standard/string.c#L1794

As seen in the code below, str_contains could be implemented in terms of strpos like so:

return '' === $needle || false !== strpos($haystack, $needle);

I would check what php_memnstr from PHP is. Maybe we have compatible function. If not, we could add one and use it in places where PHP uses it.

Maybe php_memnstr is identical to the newly introduced contains method, but I suggest re-checking that.

Also: you can run benchmarks using ktest utility.
https://habr.com/ru/company/vk/blog/572424/