Add code style

CODE-STYLE.md

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+# Names
+## Namespace Names
+Namespaces should be written in PascalCase.
+
+## File Names
+Code directories should have their name written in PascalCase. Code files should contain only one class and have the name of that class.
+In case of multiple class definitions in one file, it's name should be the same as the "primary" class name.
+Non-code directories, non-class and non-code files should be named in lisp-case.
+
+## Variable Names
+Variable names should be written in camelCase. This also applies to function arguments, class instance names and methods.
+
+## Constant Names
+Constants are written in SCREAMING_SNAKE_CASE, but should be declared case-insensetive.
+
+## Class Names
+Classes in OpenVK should belong to `openvk\` namespace and be in the corresponding directory (according to PSR-4). Names of classes should be written in PascalCase.
+
+## Function Names
+camelCase and snake_case are allowed, but first one is the recommended way. This rule does not apply to class methods, which are written in camelCase only.
+
+---
+
+# Coding Rules
+## File header
+All OpenVK files must start with `<?php` open-tag followed by `declare(strict_types=1);` on the same line. The next line must contain namespace.
+The lines after must contain use-declarations, each on it's own line (usage of {} operator is OK), if there is any. Then there must be an empty line. Example:
+```php
+<?php declare(strict_types=1);
+namespace openvk;
+use Chandler\Database\DatabaseConnection;
+use Nette\Utils\{Image, FileSystem};
+
+class ...
+```
+
+## NULL
+Null should be written as constant, all-uppercase: `NULL`.
+
+## Nullable (optional) pointer arguments
+Optional pointer arguments should default to `nullptr`: `function something(&int? $myPointer = nullptr)`. `nullptr` must be written in lisp-case (lowercase).
+
+## Comparing to NULL
+In OpenVK `is_null` is the preferred way to check for equality to NULL. `??` must be used in assignments and where else possible.
+In case if value can either be NULL or truthy, "boolean not" should be used to check if value is not null: `if(!$var)`.
+
+## Arrays
+Arrays must be defined with modern syntax: `[1, 2, 3]` (NOT `array(1, 2, 3)`).
+Same applies to `list` construction: use `[$a, , $b] = $arr;` instead of `list($a, , $b) = $arr;`
+
+## Casts
+Typecasts must be done with modern syntax where possible: `(type) $var`. Int-to-string, string-to-int, etc conversions should also be dont with modern casting
+syntax where possible, but should use `ctype_` functions where needed. `gettype`, `settype` should be used in dynamic programming only.
+
+## Goto
+```goto``` should be avoided.
+
+## `continue n; `
+It is preferable to use `continue n`, `break n` instead of guarding flags:
+```php
+# COOL AND GOOD
+foreach($a as $b)
+    foreach($b as $c)
+        if($b == $c)
+            break 2;
+
+# BRUH
+foreach($a as $b) {
+    $shouldBreak = false;
+    foreach($b as $c)
+        if($b == $c)
+            $shouldBreak = true;
+    
+    if($shouldBreak)
+        break;
+}
+```
+
+## Comments
+In OpenVK we use Perl-style `#` for single-line comments.
+
+---
+
+# Formatting
+## Variables
+It is preferable to declare only one variable per line in the code.
+
+## Indentation
+All things in OpenVK must be properly indented by a sequence of 4 spaces. Not tabs. \
+When there are several variable declarations listed together, line up the variables:
+```php
+# OK
+$photos = (new Photos)->where("meow", true);
+$photo  = $photos->fetch();
+$arr    = [
+    "a"  => 10,
+    "bb" => true,
+];
+
+# NOT OK
+$photos = (new Photos)->where("meow", true);
+$photo = $photos->fetch();
+$arr    = [
+    "a" => 10,
+    "bb" => true,
+];
+```
+
+## Tab/Space
++ **Do not use tabs**. Use spaces, as tabs are defined differently for different editors and printers.
++ Put one space after a comma and semicolons: `exp(1, 2)` `for($i = 1; $i < 100; $i++)`
++ Put one space around assignment operators: `$a = 1`
++ Always put a space around conditional operators: `$a = ($a > $b) ? $a : $b`
++ Do not put spaces between unary operators and their operands, primary operators and keywords:
+```php
+# OK
+-$a;
+$a++;
+$b[1] = $a;
+fun($b);
+if($a) { ... }
+
+# NOT OK
+- $a;
+$a ++;
+$b [1] = $a;
+fun ($b);
+if ($a) { ... }
+```
+
+## Blank Lines
++ Use blank lines to create paragraphs in the code or comments to make the code more understandable
++ Use blank lines before `return` statement if it isn't the only statement in the block
++ Use blank lines after shorthand if/else/etc
+```php
+# OK
+if($a)
+    return $x;
+    
+doSomething();
+
+return "yay";
+
+# NOT OK
+if($a) return $x; # return must be on separate line
+doSomething(); # doSomething must be separated by an extra blank line after short if/else
+return "yay"; # do use blank lines before return statement
+```
+
+
+## Method/Function Arguments
++ When all arguments for a function do not fit on one line, try to line up the first argument in each line:
+![image](https://user-images.githubusercontent.com/34442450/167248563-21fb01be-181d-48b9-ac0c-dc953c0a12cf.png)
+
++ If the argument lists are still too long to fit on the line, you may line up the arguments with the method name instead.
+
+## Maximum characters per line
+Lines should be no more than 80 characters long.
+
+## Usage of curly braces
++ Curly braces should be on separate line for class, method, and function definitions.
++ In loops, if/else, try/catch, switch constructions the opening brace should be on the same line as the operator.
++ Braces must be ommited if the block contains only one statement **AND** the related blocks are also single statemented.
++ Nested single-statement+operator blocks must not be surrounded by braces.
+```php
+# OK
+class A
+{
+    function doSomethingFunny(): int
+    {
+        return 2;
+    }
+}
+
+if(true) {
+    doSomething();
+    doSomethingElse();
+} else {
+    doSomethingFunny();
+}
+
+if($a)
+    return false;
+else
+    doSomething();
+    
+foreach($b as $c => $d)
+    if($c == $d)
+        unset($b[$c]);
+
+# NOT OK
+class A {
+    function doSomethingFunny(): int {
+        return 2;
+    }
+}
+
+if(true) {
+    doSomething();
+    doSomethingElse();
+} else
+    doSomethingFunny(); # why?
+
+if($a) {
+    return false;
+} else {
+    doSomething();
+}
+    
+foreach($b as $c => $d) {
+    if($c == $d)
+        unset($b[$c]);
+}
+
+# lmao
+if($a) { doSomething(); } else doSomethingElse();
+```
+
+## if/else, try/catch
++ Operators must not be indented with space from their operands but must have 1-space margin from braces:
+```php
+# OK
+if($a) {
+    doSomething();
+    doSomethingElse();
+} else if($b) {
+    try {
+        nukeSaintPetersburg('😈');
+    } finally {
+        return PEACE;
+    }
+}
+
+# NOT OK
+if ($a) { # do not add space between control flow operator IF and it's operand
+    doSomething();
+    doSomethingElse();
+}elseif($b){ # do add margin from braces; also ELSE and IF should be separate here
+    try{
+        nukeSaintPetersburg('😈');
+    }finally{
+        return PEACE;
+    }
+}
+```
+
+## Switches
++ `break` must be on same indentation level as the code of le case (not the case definiton itself)
++ If there is no need to `break` a comment `# NOTICE falling through` must be places instead
+```php
+# OK
+switch($a) {
+    case 1:
+        echo $a;
+        break;
+    
+    case 2:
+        echo $a++;
+        # NOTICE falling through
+    
+    default:
+        echo "c";
+}
+
+# NOT OK
+switch($a) {
+    case 1:
+        echo $a;
+    break;
+    
+    case 2:
+        echo $a++;
+    
+    default:
+        echo "c";
+}
+```