Single line conditions

When using simple conditions for early returns / guard statements the current formatting is quite verbose:

function test($arg1) {
  if (!$arg) return;

  for ($i = 0; $i < 10; $i++) {
    if ($i % 2 === 0) continue;
    // do something if the number is odd
  }
}

will be converted to:

function test($arg1) {
  if (!$arg) {
    return;
  }

  for ($i = 0; $i < 10; $i++) {
    if ($i % 2 === 0) {
      continue;
    }
    // do something if the number is odd
  }
}

It would be great if these single line conditions would be preserved. Alot of formatters for c-style languages like prettier for javascript or ClangFormat allow this, resulting in much more concise code.

从 issue 中的 PHP 示例开始，检查 formatter 对单行提前返回、guard statement 和循环控制的处理方式。确定当前的块扩展是如何实现的，并在定义预期保留的格式之前，找出相关的现有测试。完成的标准是这些单行条件保持简洁，同时其他格式化行为不变。