Add documentation for parameter types and return types

Author: clue

Diff for: README.md

@@ -18,6 +18,7 @@ A trivial implementation of timeouts for `Promise`s, built on top of [ReactPHP](
     * [reject()](#reject)
         * [Reject cancellation](#reject-cancellation)
     * [TimeoutException](#timeoutexception)
+        * [getTimeout()](#gettimeout)
 * [Install](#install)
 * [Tests](#tests)
 * [License](#license)
@@ -51,8 +52,8 @@ Timer\timeout(…);
 
 ### timeout()
 
-The `timeout(PromiseInterface $promise, $time, LoopInterface $loop = null)` function
-can be used to *cancel* operations that take *too long*.
+The `timeout(PromiseInterface<mixed, Exception|mixed> $promise, float $time, ?LoopInterface $loop = null): PromiseInterface<mixed, TimeoutException|Exception|mixed>` function can be used to
+*cancel* operations that take *too long*.
 You need to pass in an input `$promise` that represents a pending operation and timeout parameters.
 It returns a new `Promise` with the following resolution behavior:
 
@@ -284,8 +285,8 @@ For more details on the promise primitives, please refer to the
 
 ### resolve()
 
-The `resolve($time, LoopInterface $loop = null)` function can be used to create a new Promise that
-resolves in `$time` seconds with the `$time` as the fulfillment value.
+The `resolve(float $time, ?LoopInterface $loop = null): PromiseInterface<float, RuntimeException>` function can be used to
+create a new Promise that resolves in `$time` seconds with the `$time` as the fulfillment value.
 
 ```php
 React\Promise\Timer\resolve(1.5)->then(function ($time) {
@@ -318,8 +319,8 @@ This will abort the timer and *reject* with a `RuntimeException`.
 
 ### reject()
 
-The `reject($time, LoopInterface $loop = null)` function can be used to create a new Promise
-which rejects in `$time` seconds with a `TimeoutException`.
+The `reject(float $time, ?LoopInterface $loop = null): PromiseInterface<void, TimeoutException|RuntimeException>` function can be used to
+create a new Promise which rejects in `$time` seconds with a `TimeoutException`.
 
 ```php
 React\Promise\Timer\reject(2.0)->then(null, function (React\Promise\Timer\TimeoutException $e) {
@@ -357,7 +358,11 @@ This will abort the timer and *reject* with a `RuntimeException`.
 
 The `TimeoutException` extends PHP's built-in `RuntimeException`.
 
-The `getTimeout()` method can be used to get the timeout value in seconds.
+
+#### getTimeout()
+
+The `getTimeout(): float` method can be used to
+get the timeout value in seconds.
 
 ## Install
 

Diff for: src/TimeoutException.php

@@ -6,15 +6,25 @@
 
 class TimeoutException extends RuntimeException
 {
+    /** @var float */
     private $timeout;
 
+    /**
+     * @param float                      $timeout
+     * @param ?string                    $message
+     * @param ?int                       $code
+     * @param null|\Exception|\Throwable $previous
+     */
     public function __construct($timeout, $message = null, $code = null, $previous = null)
     {
         parent::__construct($message, $code, $previous);
 
         $this->timeout = $timeout;
     }
 
+    /**
+     * @return float
+     */
     public function getTimeout()
     {
         return $this->timeout;

Diff for: src/functions.php

@@ -8,6 +8,12 @@
 use React\Promise\Promise;
 use React\Promise\PromiseInterface;
 
+/**
+ * @param PromiseInterface<mixed, \Exception|mixed> $promise
+ * @param float $time
+ * @param ?LoopInterface $loop
+ * @return PromiseInterface<mixed, TimeoutException|\Exception|mixed>
+ */
 function timeout(PromiseInterface $promise, $time, LoopInterface $loop = null)
 {
     // cancelling this promise will only try to cancel the input promise,
@@ -61,12 +67,18 @@ function timeout(PromiseInterface $promise, $time, LoopInterface $loop = null)
     }, $canceller);
 }
 
+/**
+ * @param float $time
+ * @param ?LoopInterface $loop
+ * @return PromiseInterface<float, \RuntimeException>
+ */
 function resolve($time, LoopInterface $loop = null)
 {
     if ($loop === null) {
         $loop = Loop::get();
     }
 
+    $timer = null;
     return new Promise(function ($resolve) use ($loop, $time, &$timer) {
         // resolve the promise when the timer fires in $time seconds
         $timer = $loop->addTimer($time, function () use ($time, $resolve) {
@@ -82,6 +94,11 @@ function resolve($time, LoopInterface $loop = null)
     });
 }
 
+/**
+ * @param float         $time
+ * @param LoopInterface $loop
+ * @return PromiseInterface<void, TimeoutException|\RuntimeException>
+ */
 function reject($time, LoopInterface $loop = null)
 {
     return resolve($time, $loop)->then(function ($time) {