move to amphp

bin/php-language-server.php

@@ -1,8 +1,12 @@
 <?php
 
-use LanguageServer\{LanguageServer, ProtocolStreamReader, ProtocolStreamWriter, StderrLogger};
+use Amp\ByteStream\ResourceInputStream;
-use Sabre\Event\Loop;
+use Amp\ByteStream\ResourceOutputStream;
+use Amp\Loop;
+use Amp\Socket\ClientSocket;
+use Amp\Socket\ServerSocket;
 use Composer\XdebugHandler\XdebugHandler;
+use LanguageServer\{LanguageServer, ProtocolStreamReader, ProtocolStreamWriter, StderrLogger};
 
 $options = getopt('', ['tcp::', 'tcp-server::', 'memory-limit::']);
 
@@ -42,69 +46,51 @@ unset($xdebugHandler);
 if (!empty($options['tcp'])) {
     // Connect to a TCP server
     $address = $options['tcp'];
-    $socket = stream_socket_client('tcp://' . $address, $errno, $errstr);
+    $server = function () use ($logger, $address) {
-    if ($socket === false) {
+        /** @var ClientSocket $socket */
-        $logger->critical("Could not connect to language client. Error $errno\n$errstr");
+        $socket = yield Amp\Socket\connect('tcp://' . $address);
-        exit(1);
+        $ls = new LanguageServer(
-    }
+            new ProtocolStreamReader($socket),
-    stream_set_blocking($socket, false);
+            new ProtocolStreamWriter($socket)
-    $ls = new LanguageServer(
+        );
-        new ProtocolStreamReader($socket),
+        yield $ls->getshutdownDeferred();
-        new ProtocolStreamWriter($socket)
+    };
-    );
-    Loop\run();
 } else if (!empty($options['tcp-server'])) {
     // Run a TCP Server
     $address = $options['tcp-server'];
-    $tcpServer = stream_socket_server('tcp://' . $address, $errno, $errstr);
+    $server = function () use ($logger, $address) {
-    if ($tcpServer === false) {
+
-        $logger->critical("Could not listen on $address. Error $errno\n$errstr");
+        $server = Amp\Socket\listen('tcp://' . $address);
-        exit(1);
+
-    }
+        $logger->debug("Server listening on $address");
-    $logger->debug("Server listening on $address");
+
-    $pcntlAvailable = extension_loaded('pcntl');
+        while ($socket = yield $server->accept()) {
-    if (!$pcntlAvailable) {
+            /** @var ServerSocket $socket */
-        $logger->notice('PCNTL is not available. Only a single connection will be accepted');
+            list($ip, $port) = \explode(':', $socket->getRemoteAddress());
-    }
+
-    while ($socket = stream_socket_accept($tcpServer, -1)) {
+            $logger->debug("Accepted connection from {$ip}:{$port}." . PHP_EOL);
-        $logger->debug('Connection accepted');
+
-        stream_set_blocking($socket, false);
+            Loop::run(function () use ($socket) {
-        if ($pcntlAvailable) {
+                $ls = new LanguageServer(
-            // If PCNTL is available, fork a child process for the connection
+                    new ProtocolStreamReader($socket),
-            // An exit notification will only terminate the child process
+                    new ProtocolStreamWriter($socket)
-            $pid = pcntl_fork();
+                );
-            if ($pid === -1) {
+                yield $ls->getshutdownDeferred();
-                $logger->critical('Could not fork');
+            });
-                exit(1);
-            } else if ($pid === 0) {
-                // Child process
-                $reader = new ProtocolStreamReader($socket);
-                $writer = new ProtocolStreamWriter($socket);
-                $reader->on('close', function () use ($logger) {
-                    $logger->debug('Connection closed');
-                });
-                $ls = new LanguageServer($reader, $writer);
-                Loop\run();
-                // Just for safety
-                exit(0);
-            }
-        } else {
-            // If PCNTL is not available, we only accept one connection.
-            // An exit notification will terminate the server
-            $ls = new LanguageServer(
-                new ProtocolStreamReader($socket),
-                new ProtocolStreamWriter($socket)
-            );
-            Loop\run();
         }
-    }
+    };
 } else {
     // Use STDIO
     $logger->debug('Listening on STDIN');
-    stream_set_blocking(STDIN, false);
+    $inputStream = new ResourceInputStream(STDIN);
+    $outputStream = new ResourceOutputStream(STDOUT);
     $ls = new LanguageServer(
-        new ProtocolStreamReader(STDIN),
+        new ProtocolStreamReader($inputStream),
-        new ProtocolStreamWriter(STDOUT)
+        new ProtocolStreamWriter($outputStream)
     );
-    Loop\run();
+    $server = function () use ($ls) {
+        yield $ls->getshutdownDeferred();
+    };
 }
+
+Loop::run($server);

composer.json

@@ -22,17 +22,21 @@
     ],
     "require": {
         "php": "^7.0",
+        "amphp/byte-stream": "^1.5",
+        "amphp/cache": "^1.2",
+        "amphp/file": "^0.3.5",
+        "amphp/socket": "^0.10.11",
         "composer/xdebug-handler": "^1.0",
         "felixfbecker/advanced-json-rpc": "^3.0.0",
         "felixfbecker/language-server-protocol": "^1.0.1",
         "jetbrains/phpstorm-stubs": "dev-master",
+        "league/event": "^2.2",
+        "league/uri-parser": "^1.4",
         "microsoft/tolerant-php-parser": "0.0.*",
         "netresearch/jsonmapper": "^1.0",
         "php-ds/php-ds": "^1.2",
         "phpdocumentor/reflection-docblock": "^4.0.0",
         "psr/log": "^1.0",
-        "sabre/event": "^5.0",
-        "sabre/uri": "^2.0",
         "webmozart/glob": "^4.1",
         "webmozart/path-util": "^2.3"
     },

src/Cache/Cache.php

@@ -1,10 +1,8 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer\Cache;
 
-use Sabre\Event\Promise;
-
 /**
  * A key/value store for caching purposes
  */
@@ -14,16 +12,16 @@ interface Cache
      * Gets a value from the cache
      *
      * @param string $key
-     * @return Promise <mixed>
+     * @return \Generator <mixed>
      */
-    public function get(string $key): Promise;
+    public function get(string $key): \Generator;
 
     /**
      * Sets a value in the cache
      *
      * @param string $key
-     * @param mixed  $value
+     * @param mixed $value
-     * @return Promise
+     * @return \Generator
      */
-    public function set(string $key, $value): Promise;
+    public function set(string $key, $value): \Generator;
 }

src/Cache/ClientCache.php

@@ -1,5 +1,5 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer\Cache;
 
@@ -30,24 +30,22 @@ class ClientCache implements Cache
      * @param string $key
      * @return Promise <mixed>
      */
-    public function get(string $key): Promise
+    public function get(string $key): \Generator
     {
-        return $this->client->xcache->get($key)->then('unserialize')->otherwise(function () {
+        $cached = yield from $this->client->xcache->get($key);
-            // Ignore
+        $obj = unserialize($cached);
-        });
+        return $obj;
     }
 
     /**
      * Sets a value in the cache
      *
      * @param string $key
-     * @param mixed  $value
+     * @param mixed $value
      * @return Promise
      */
-    public function set(string $key, $value): Promise
+    public function set(string $key, $value): \Generator
     {
-        return $this->client->xcache->set($key, serialize($value))->otherwise(function () {
+        return yield from $this->client->xcache->set($key, serialize($value));
-            // Ignore
-        });
     }
 }

src/Cache/FileSystemCache.php

@@ -1,10 +1,8 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer\Cache;
 
-use Sabre\Event\Promise;
-
 /**
  * Caches content on the file system
  */
@@ -30,18 +28,16 @@ class FileSystemCache implements Cache
      * Gets a value from the cache
      *
      * @param string $key
-     * @return Promise <mixed>
+     * @return \Generator <mixed>
      */
-    public function get(string $key): Promise
+    public function get(string $key): \Generator
     {
         try {
             $file = $this->cacheDir . urlencode($key);
-            if (!file_exists($file)) {
+            $content = yield \Amp\File\get($file);
-                return Promise\resolve(null);
+            return unserialize($content);
-            }
-            return Promise\resolve(unserialize(file_get_contents($file)));
         } catch (\Exception $e) {
-            return Promise\resolve(null);
+            return null;
         }
     }
 
@@ -49,19 +45,19 @@ class FileSystemCache implements Cache
      * Sets a value in the cache
      *
      * @param string $key
-     * @param mixed  $value
+     * @param mixed $value
-     * @return Promise
+     * @return \Generator
      */
-    public function set(string $key, $value): Promise
+    public function set(string $key, $value): \Generator
     {
-        try {
+        $file = $this->cacheDir . urlencode($key);
-            $file = $this->cacheDir . urlencode($key);
+        $dir = dirname($file);
-            if (!file_exists($this->cacheDir)) {
+        if (yield \Amp\File\isfile($dir)) {
-                mkdir($this->cacheDir);
+            yield \Amp\File\unlink($dir);
-            }
-            file_put_contents($file, serialize($value));
-        } finally {
-            return Promise\resolve(null);
         }
+        if (!yield \Amp\File\exists($dir)) {
+            yield \Amp\File\mkdir($dir, 0777, true);
+        }
+        yield \Amp\File\put($file, serialize($value));
     }
 }

src/Client/TextDocument.php

@@ -1,5 +1,5 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer\Client;
 
@@ -36,9 +36,9 @@ class TextDocument
      * @param Diagnostic[] $diagnostics
      * @return Promise <void>
      */
-    public function publishDiagnostics(string $uri, array $diagnostics): Promise
+    public function publishDiagnostics(string $uri, array $diagnostics): \Generator
     {
-        return $this->handler->notify('textDocument/publishDiagnostics', [
+        yield from $this->handler->notify('textDocument/publishDiagnostics', [
             'uri' => $uri,
             'diagnostics' => $diagnostics
         ]);
@@ -51,13 +51,12 @@ class TextDocument
      * @param TextDocumentIdentifier $textDocument The document to get the content for
      * @return Promise <TextDocumentItem> The document's current content
      */
-    public function xcontent(TextDocumentIdentifier $textDocument): Promise
+    public function xcontent(TextDocumentIdentifier $textDocument): \Generator
     {
-        return $this->handler->request(
+        $result = yield from  $this->handler->request(
             'textDocument/xcontent',
             ['textDocument' => $textDocument]
-        )->then(function ($result) {
+        );
-            return $this->mapper->map($result, new TextDocumentItem);
+        return $this->mapper->map($result, new TextDocumentItem);
-        });
     }
 }

src/Client/Window.php

@@ -41,8 +41,8 @@ class Window
      * @param string $message
      * @return Promise <void>
      */
-    public function logMessage(int $type, string $message): Promise
+    public function logMessage(int $type, string $message): \Generator
     {
-        return $this->handler->notify('window/logMessage', ['type' => $type, 'message' => $message]);
+        yield from $this->handler->notify('window/logMessage', ['type' => $type, 'message' => $message]);
     }
 }

src/Client/Workspace.php

@@ -1,5 +1,5 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer\Client;
 
@@ -35,13 +35,12 @@ class Workspace
      * @param string $base The base directory (defaults to the workspace)
      * @return Promise <TextDocumentIdentifier[]> Array of documents
      */
-    public function xfiles(string $base = null): Promise
+    public function xfiles(string $base = null): \Generator
     {
-        return $this->handler->request(
+        $textDocuments = yield from $this->handler->request(
             'workspace/xfiles',
             ['base' => $base]
-        )->then(function (array $textDocuments) {
+        );
-            return $this->mapper->mapArray($textDocuments, [], TextDocumentIdentifier::class);
+        return $this->mapper->mapArray($textDocuments, [], TextDocumentIdentifier::class);
-        });
     }
 }

src/Client/XCache.php

@@ -1,5 +1,5 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer\Client;
 
@@ -25,18 +25,18 @@ class XCache
      * @param string $key
      * @return Promise <mixed>
      */
-    public function get(string $key): Promise
+    public function get(string $key): \Generator
     {
-        return $this->handler->request('xcache/get', ['key' => $key]);
+        return yield from $this->handler->request('xcache/get', ['key' => $key]);
     }
 
     /**
      * @param string $key
-     * @param mixed  $value
+     * @param mixed $value
      * @return Promise <mixed>
      */
-    public function set(string $key, $value): Promise
+    public function set(string $key, $value): \Generator
     {
-        return $this->handler->notify('xcache/set', ['key' => $key, 'value' => $value]);
+        return yield from $this->handler->notify('xcache/set', ['key' => $key, 'value' => $value]);
     }
 }

src/ClientHandler.php

@@ -1,10 +1,12 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer;
 
 use AdvancedJsonRpc;
-use Sabre\Event\Promise;
+use Amp\Deferred;
+use Amp\Loop;
+use LanguageServer\Event\MessageEvent;
 
 class ClientHandler
 {
@@ -35,31 +37,35 @@ class ClientHandler
      *
      * @param string $method The method to call
      * @param array|object $params The method parameters
-     * @return Promise <mixed> Resolved with the result of the request or rejected with an error
+     * @return \Generator <mixed> Resolved with the result of the request or rejected with an error
      */
-    public function request(string $method, $params): Promise
+    public function request(string $method, $params): \Generator
     {
         $id = $this->idGenerator->generate();
-        return $this->protocolWriter->write(
+        $deferred = new Deferred();
-            new Message(
+        $listener = function (MessageEvent $messageEvent) use ($id, $deferred, &$listener) {
-                new AdvancedJsonRpc\Request($id, $method, (object)$params)
+            $msg = $messageEvent->getMessage();
-            )
+            Loop::defer(function () use (&$listener, $deferred, $id, $msg) {
-        )->then(function () use ($id) {
-            $promise = new Promise;
-            $listener = function (Message $msg) use ($id, $promise, &$listener) {
                 if (AdvancedJsonRpc\Response::isResponse($msg->body) && $msg->body->id === $id) {
                     // Received a response
                     $this->protocolReader->removeListener('message', $listener);
                     if (AdvancedJsonRpc\SuccessResponse::isSuccessResponse($msg->body)) {
-                        $promise->fulfill($msg->body->result);
+                        $deferred->resolve($msg->body->result);
                     } else {
-                        $promise->reject($msg->body->error);
+                        $deferred->fail($msg->body->error);
                     }
                 }
-            };
+            });
-            $this->protocolReader->on('message', $listener);
+        };
-            return $promise;
+        $this->protocolReader->addListener('message', $listener);
-        });
+
+        yield from $this->protocolWriter->write(
+            new Message(
+                new AdvancedJsonRpc\Request($id, $method, (object)$params)
+            )
+        );
+
+        return yield $deferred->promise();
     }
 
     /**
@@ -67,11 +73,11 @@ class ClientHandler
      *
      * @param string $method The method to call
      * @param array|object $params The method parameters
-     * @return Promise <null> Will be resolved as soon as the notification has been sent
+     * @return \Generator <null> Will be resolved as soon as the notification has been sent
      */
-    public function notify(string $method, $params): Promise
+    public function notify(string $method, $params): \Generator
     {
-        return $this->protocolWriter->write(
+        return yield from $this->protocolWriter->write(
             new Message(
                 new AdvancedJsonRpc\Notification($method, (object)$params)
             )

src/ComposerScripts.php

@@ -1,16 +1,16 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer;
 
-use LanguageServer\FilesFinder\FileSystemFilesFinder;
+use Amp\Loop;
 use LanguageServer\ContentRetriever\FileSystemContentRetriever;
+use LanguageServer\FilesFinder\FileSystemFilesFinder;
 use LanguageServer\Index\StubsIndex;
+use Microsoft\PhpParser;
 use phpDocumentor\Reflection\DocBlockFactory;
 use Webmozart\PathUtil\Path;
-use Sabre\Uri;
+use function League\Uri\parse;
-use function Sabre\Event\coroutine;
-use Microsoft\PhpParser;
 
 foreach ([__DIR__ . '/../../../autoload.php', __DIR__ . '/../autoload.php', __DIR__ . '/../vendor/autoload.php'] as $file) {
     if (file_exists($file)) {
@@ -23,8 +23,7 @@ class ComposerScripts
 {
     public static function parseStubs()
     {
-        coroutine(function () {
+        Loop::run(function () {
-
             $index = new StubsIndex;
 
             $finder = new FileSystemFilesFinder;
@@ -44,20 +43,19 @@ class ComposerScripts
                 throw new \Exception('jetbrains/phpstorm-stubs package not found');
             }
 
-            $uris = yield $finder->find("$stubsLocation/**/*.php");
+            $uris = yield from $finder->find("$stubsLocation/**/*.php");
 
             foreach ($uris as $uri) {
                 echo "Parsing $uri\n";
-                $content = yield $contentRetriever->retrieve($uri);
+                $content = yield from $contentRetriever->retrieve($uri);
 
                 // Change URI to phpstubs://
-                $parts = Uri\parse($uri);
+                $parts = parse($uri);
                 $parts['path'] = Path::makeRelative($parts['path'], $stubsLocation);
                 $parts['scheme'] = 'phpstubs';
-                $uri = Uri\build($parts);
 
                 // Create a new document and add it to $index
-                new PhpDocument($uri, $content, $index, $parser, $docBlockFactory, $definitionResolver);
+                new PhpDocument((string)$uri, $content, $index, $parser, $docBlockFactory, $definitionResolver);
             }
 
             $index->setComplete();
@@ -67,6 +65,6 @@ class ComposerScripts
             $index->save();
 
             echo "Finished\n";
-        })->wait();
+        });
     }
 }

src/ContentRetriever/ClientContentRetriever.php

@@ -1,5 +1,5 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer\ContentRetriever;
 
@@ -26,11 +26,10 @@ class ClientContentRetriever implements ContentRetriever
      * @param string $uri The URI of the document
      * @return Promise <string> Resolved with the content as a string
      */
-    public function retrieve(string $uri): Promise
+    public function retrieve(string $uri): \Generator
     {
-        return $this->client->textDocument->xcontent(new TextDocumentIdentifier($uri))
+        /** @var TextDocumentItem $textDocument */
-            ->then(function (TextDocumentItem $textDocument) {
+        $textDocument = yield from $this->client->textDocument->xcontent(new TextDocumentIdentifier($uri));
-                return $textDocument->text;
+        return $textDocument->text;
-            });
     }
 }

src/ContentRetriever/ContentRetriever.php

@@ -16,5 +16,5 @@ interface ContentRetriever
      * @param string $uri The URI of the document
      * @return Promise <string> Resolved with the content as a string
      */
-    public function retrieve(string $uri): Promise;
+    public function retrieve(string $uri): \Generator;
 }

src/ContentRetriever/FileSystemContentRetriever.php

@@ -17,8 +17,8 @@ class FileSystemContentRetriever implements ContentRetriever
      * @param string $uri The URI of the document
      * @return Promise <string> Resolved with the content as a string
      */
-    public function retrieve(string $uri): Promise
+    public function retrieve(string $uri): \Generator
     {
-        return Promise\resolve(file_get_contents(uriToPath($uri)));
+        return yield \Amp\File\get(uriToPath($uri));
     }
 }

src/Event/MessageEvent.php

@@ -0,0 +1,32 @@
+<?php
+declare(strict_types=1);
+
+namespace LanguageServer\Event;
+
+use LanguageServer\Message;
+use League\Event\Event;
+
+class MessageEvent extends Event
+{
+    /**
+     * @var Message
+     */
+    private $message;
+
+    /**
+     * Create a new event instance.
+     *
+     * @param string $name
+     * @param Message $message
+     */
+    public function __construct(string $name, Message $message)
+    {
+        parent::__construct($name);
+        $this->message = $message;
+    }
+
+    public function getMessage(): Message
+    {
+        return $this->message;
+    }
+}

src/FilesFinder/ClientFilesFinder.php

@@ -1,12 +1,11 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer\FilesFinder;
 
 use LanguageServer\LanguageClient;
-use Sabre\Event\Promise;
-use Sabre\Uri;
 use Webmozart\Glob\Glob;
+use function League\Uri\parse;
 
 /**
  * Retrieves file content from the client through a textDocument/xcontent request
@@ -31,19 +30,18 @@ class ClientFilesFinder implements FilesFinder
      * If the client does not support workspace/files, it falls back to searching the file system directly.
      *
      * @param string $glob
-     * @return Promise <string[]> The URIs
+     * @return \Generator <string[]> The URIs
      */
-    public function find(string $glob): Promise
+    public function find(string $glob): \Generator
     {
-        return $this->client->workspace->xfiles()->then(function (array $textDocuments) use ($glob) {
+        $textDocuments = yield from $this->client->workspace->xfiles();
-            $uris = [];
+        $uris = [];
-            foreach ($textDocuments as $textDocument) {
+        foreach ($textDocuments as $textDocument) {
-                $path = Uri\parse($textDocument->uri)['path'];
+            $path = parse($textDocument->uri)['path'];
-                if (Glob::match($path, $glob)) {
+            if (Glob::match($path, $glob)) {
-                    $uris[] = $textDocument->uri;
+                $uris[] = $textDocument->uri;
-                }
             }
-            return $uris;
+        }
-        });
+        return $uris;
     }
 }

src/FilesFinder/FileSystemFilesFinder.php

@@ -1,12 +1,11 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer\FilesFinder;
 
-use Webmozart\Glob\Iterator\GlobIterator;
+use Webmozart\Glob\Glob;
-use Sabre\Event\Promise;
+use function Amp\File\isdir;
-use function Sabre\Event\coroutine;
+use function LanguageServer\{pathToUri};
-use function LanguageServer\{pathToUri, timeout};
 
 class FileSystemFilesFinder implements FilesFinder
 {
@@ -15,21 +14,24 @@ class FileSystemFilesFinder implements FilesFinder
      * If the client does not support workspace/xfiles, it falls back to searching the file system directly.
      *
      * @param string $glob
-     * @return Promise <string[]>
+     * @return \Amp\Promise <string[]>
      */
-    public function find(string $glob): Promise
+    public function find(string $glob): \Generator
     {
-        return coroutine(function () use ($glob) {
+        $uris = [];
-            $uris = [];
+        $basePath = \Webmozart\Glob\Glob::getBasePath($glob);
-            foreach (new GlobIterator($glob) as $path) {
+        $pathList = [$basePath];
-                // Exclude any directories that also match the glob pattern
+        while ($pathList) {
-                if (!is_dir($path)) {
+            $path = array_pop($pathList);
-                    $uris[] = pathToUri($path);
+            if (yield isdir($path)) {
+                $subFileList = yield \Amp\File\scandir($path);
+                foreach ($subFileList as $subFile) {
+                    $pathList[] = $path . DIRECTORY_SEPARATOR . $subFile;
                 }
-
+            } elseif (Glob::match($path, $glob)) {
-                yield timeout();
+                $uris[] = pathToUri($path);
             }
-            return $uris;
+        }
-        });
+        return $uris;
     }
 }

src/FilesFinder/FilesFinder.php

@@ -1,5 +1,5 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer\FilesFinder;
 
@@ -17,5 +17,5 @@ interface FilesFinder
      * @param string $glob
      * @return Promise <string[]>
      */
-    public function find(string $glob): Promise;
+    public function find(string $glob): \Generator;
 }

src/Index/AbstractAggregateIndex.php

@@ -4,12 +4,10 @@ declare(strict_types = 1);
 namespace LanguageServer\Index;
 
 use LanguageServer\Definition;
-use Sabre\Event\EmitterTrait;
+use League\Event\Emitter;
 
-abstract class AbstractAggregateIndex implements ReadableIndex
+abstract class AbstractAggregateIndex extends Emitter implements ReadableIndex
 {
-    use EmitterTrait;
-
     /**
      * Returns all indexes managed by the aggregate index
      *
@@ -29,17 +27,17 @@ abstract class AbstractAggregateIndex implements ReadableIndex
      */
     protected function registerIndex(ReadableIndex $index)
     {
-        $index->on('complete', function () {
+        $index->addListener('complete', function () {
             if ($this->isComplete()) {
                 $this->emit('complete');
             }
         });
-        $index->on('static-complete', function () {
+        $index->addListener('static-complete', function () {
             if ($this->isStaticComplete()) {
                 $this->emit('static-complete');
             }
         });
-        $index->on('definition-added', function () {
+        $index->addListener('definition-added', function () {
             $this->emit('definition-added');
         });
     }

src/Index/DependenciesIndex.php

@@ -3,6 +3,13 @@ declare(strict_types = 1);
 
 namespace LanguageServer\Index;
 
+use League\Event\EmitterInterface;
+use League\Event\EventInterface;
+use League\Event\GeneratorInterface;
+use League\Event\ListenerAcceptorInterface;
+use League\Event\ListenerInterface;
+use League\Event\ListenerProviderInterface;
+
 class DependenciesIndex extends AbstractAggregateIndex
 {
     /**

src/Index/Index.php

@@ -5,15 +5,14 @@ namespace LanguageServer\Index;
 
 use Ds\Set;
 use LanguageServer\Definition;
-use Sabre\Event\EmitterTrait;
+use League\Event\Emitter;
 
 /**
  * Represents the index of a project or dependency
  * Serializable for caching
  */
-class Index implements ReadableIndex, \Serializable
+class Index extends Emitter implements ReadableIndex, \Serializable
 {
-    use EmitterTrait;
 
     /**
      * An associative array that maps splitted fully qualified symbol names
@@ -62,7 +61,6 @@ class Index implements ReadableIndex, \Serializable
             $this->setStaticComplete();
         }
         $this->complete = true;
-        $this->emit('complete');
     }
 
     /**
@@ -73,7 +71,6 @@ class Index implements ReadableIndex, \Serializable
     public function setStaticComplete()
     {
         $this->staticComplete = true;
-        $this->emit('static-complete');
     }
 
     /**
@@ -174,8 +171,6 @@ class Index implements ReadableIndex, \Serializable
     {
         $parts = $this->splitFqn($fqn);
         $this->indexDefinition(0, $parts, $this->definitions, $definition);
-
-        $this->emit('definition-added');
     }
 
     /**
@@ -201,7 +196,7 @@ class Index implements ReadableIndex, \Serializable
      */
     public function getReferenceUris(string $fqn): \Generator
     {
-        if ($this->references[$fqn]) {
+        if (isset($this->references[$fqn])) {
             foreach ($this->references[$fqn] as $uri) {
                 yield $uri;
             }
@@ -425,7 +420,7 @@ class Index implements ReadableIndex, \Serializable
             if (isset($storage[$part])) {
                 unset($storage[$part]);
 
-                if (0 === count($storage)) {
+                if (0 === count($storage) && $level != 0) {
                     // parse again the definition tree to remove the parent
                     // when it has no more children
                     $this->removeIndexedDefinition(0, array_slice($parts, 0, $level), $rootStorage, $rootStorage);

src/Index/ReadableIndex.php

@@ -4,7 +4,7 @@ declare(strict_types = 1);
 namespace LanguageServer\Index;
 
 use LanguageServer\Definition;
-use Sabre\Event\EmitterInterface;
+use League\Event\EmitterInterface;
 
 /**
  * The ReadableIndex interface provides methods to lookup definitions and references

src/Indexer.php

@@ -1,15 +1,15 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer;
 
+use Amp\Delayed;
 use LanguageServer\Cache\Cache;
 use LanguageServer\FilesFinder\FilesFinder;
 use LanguageServer\Index\{DependenciesIndex, Index};
 use LanguageServerProtocol\MessageType;
 use Webmozart\PathUtil\Path;
 use Sabre\Event\Promise;
-use function Sabre\Event\coroutine;
 
 class Indexer
 {
@@ -64,14 +64,14 @@ class Indexer
     private $composerJson;
 
     /**
-     * @param FilesFinder       $filesFinder
+     * @param FilesFinder $filesFinder
-     * @param string            $rootPath
+     * @param string $rootPath
-     * @param LanguageClient    $client
+     * @param LanguageClient $client
-     * @param Cache             $cache
+     * @param Cache $cache
      * @param DependenciesIndex $dependenciesIndex
-     * @param Index             $sourceIndex
+     * @param Index $sourceIndex
      * @param PhpDocumentLoader $documentLoader
-     * @param \stdClass|null    $composerLock
+     * @param \stdClass|null $composerLock
      */
     public function __construct(
         FilesFinder $filesFinder,
@@ -100,132 +100,129 @@ class Indexer
      *
      * @return Promise <void>
      */
-    public function index(): Promise
+    public function index(): \Generator
     {
-        return coroutine(function () {
+        $pattern = Path::makeAbsolute('**/*.php', $this->rootPath);
+        $uris = yield from $this->filesFinder->find($pattern);
 
-            $pattern = Path::makeAbsolute('**/*.php', $this->rootPath);
+        $count = count($uris);
-            $uris = yield $this->filesFinder->find($pattern);
+        $startTime = microtime(true);
+        yield from $this->client->window->logMessage(MessageType::INFO, "$count files total");
 
-            $count = count($uris);
+        /** @var string[] */
-            $startTime = microtime(true);
+        $source = [];
-            $this->client->window->logMessage(MessageType::INFO, "$count files total");
+        /** @var string[][] */
+        $deps = [];
 
-            /** @var string[] */
+        foreach ($uris as $uri) {
-            $source = [];
+            $packageName = getPackageName($uri, $this->composerJson);
-            /** @var string[][] */
+            if ($this->composerLock !== null && $packageName) {
-            $deps = [];
+                // Dependency file
+                if (!isset($deps[$packageName])) {
+                    $deps[$packageName] = [];
+                }
+                $deps[$packageName][] = $uri;
+            } else {
+                // Source file
+                $source[] = $uri;
+            }
+        }
 
-            foreach ($uris as $uri) {
+        // Index source
-                $packageName = getPackageName($uri, $this->composerJson);
+        // Definitions and static references
-                if ($this->composerLock !== null && $packageName) {
+        yield from $this->client->window->logMessage(MessageType::INFO, 'Indexing project for definitions and static references');
-                    // Dependency file
+        yield from $this->indexFiles($source);
-                    if (!isset($deps[$packageName])) {
+        $this->sourceIndex->setStaticComplete();
-                        $deps[$packageName] = [];
+        // Dynamic references
-                    }
+        yield from $this->client->window->logMessage(MessageType::INFO, 'Indexing project for dynamic references');
-                    $deps[$packageName][] = $uri;
+        yield from $this->indexFiles($source);
-                } else {
+        $this->sourceIndex->setComplete();
-                    // Source file
+
-                    $source[] = $uri;
+        // Index dependencies
+        yield from $this->client->window->logMessage(MessageType::INFO, count($deps) . ' Packages');
+        foreach ($deps as $packageName => $files) {
+            // Find version of package and check cache
+            $packageKey = null;
+            $cacheKey = null;
+            $index = null;
+            foreach (array_merge($this->composerLock->packages, (array)$this->composerLock->{'packages-dev'}) as $package) {
+                // Check if package name matches and version is absolute
+                // Dynamic constraints are not cached, because they can change every time
+                $packageVersion = ltrim($package->version, 'v');
+                if ($package->name === $packageName && strpos($packageVersion, 'dev') === false) {
+                    $packageKey = $packageName . ':' . $packageVersion;
+                    $cacheKey = self::CACHE_VERSION . ':' . $packageKey;
+                    // Check cache
+                    $index = yield from $this->cache->get($cacheKey);
+                    break;
                 }
             }
+            $index = null;
+            if ($index !== null) {
+                // Cache hit
+                $this->dependenciesIndex->setDependencyIndex($packageName, $index);
+                yield from $this->client->window->logMessage(MessageType::INFO, "Restored $packageKey from cache");
+            } else {
+                // Cache miss
+                $index = $this->dependenciesIndex->getDependencyIndex($packageName);
 
-            // Index source
+                // Index definitions and static references
-            // Definitions and static references
+                yield from $this->client->window->logMessage(MessageType::INFO, 'Indexing ' . ($packageKey ?? $packageName) . ' for definitions and static references');
-            $this->client->window->logMessage(MessageType::INFO, 'Indexing project for definitions and static references');
+                yield from $this->indexFiles($files);
-            yield $this->indexFiles($source);
+                $index->setStaticComplete();
-            $this->sourceIndex->setStaticComplete();
-            // Dynamic references
-            $this->client->window->logMessage(MessageType::INFO, 'Indexing project for dynamic references');
-            yield $this->indexFiles($source);
-            $this->sourceIndex->setComplete();
 
-            // Index dependencies
+                // Index dynamic references
-            $this->client->window->logMessage(MessageType::INFO, count($deps) . ' Packages');
+                yield from $this->client->window->logMessage(MessageType::INFO, 'Indexing ' . ($packageKey ?? $packageName) . ' for dynamic references');
-            foreach ($deps as $packageName => $files) {
+                yield from $this->indexFiles($files);
-                // Find version of package and check cache
+                $index->setComplete();
-                $packageKey = null;
+
-                $cacheKey = null;
+                // If we know the version (cache key), save index for the dependency in the cache
-                $index = null;
+                if ($cacheKey !== null) {
-                foreach (array_merge($this->composerLock->packages, (array)$this->composerLock->{'packages-dev'}) as $package) {
+                    yield from $this->client->window->logMessage(MessageType::INFO, "Storing $packageKey in cache");
-                    // Check if package name matches and version is absolute
+                    yield from $this->cache->set($cacheKey, $index);
-                    // Dynamic constraints are not cached, because they can change every time
-                    $packageVersion = ltrim($package->version, 'v');
-                    if ($package->name === $packageName && strpos($packageVersion, 'dev') === false) {
-                        $packageKey = $packageName . ':' . $packageVersion;
-                        $cacheKey = self::CACHE_VERSION . ':' . $packageKey;
-                        // Check cache
-                        $index = yield $this->cache->get($cacheKey);
-                        break;
-                    }
-                }
-                if ($index !== null) {
-                    // Cache hit
-                    $this->dependenciesIndex->setDependencyIndex($packageName, $index);
-                    $this->client->window->logMessage(MessageType::INFO, "Restored $packageKey from cache");
                 } else {
-                    // Cache miss
+                    yield from $this->client->window->logMessage(MessageType::WARNING, "Could not compute cache key for $packageName");
-                    $index = $this->dependenciesIndex->getDependencyIndex($packageName);
-
-                    // Index definitions and static references
-                    $this->client->window->logMessage(MessageType::INFO, 'Indexing ' . ($packageKey ?? $packageName) . ' for definitions and static references');
-                    yield $this->indexFiles($files);
-                    $index->setStaticComplete();
-
-                    // Index dynamic references
-                    $this->client->window->logMessage(MessageType::INFO, 'Indexing ' . ($packageKey ?? $packageName) . ' for dynamic references');
-                    yield $this->indexFiles($files);
-                    $index->setComplete();
-
-                    // If we know the version (cache key), save index for the dependency in the cache
-                    if ($cacheKey !== null) {
-                        $this->client->window->logMessage(MessageType::INFO, "Storing $packageKey in cache");
-                        $this->cache->set($cacheKey, $index);
-                    } else {
-                        $this->client->window->logMessage(MessageType::WARNING, "Could not compute cache key for $packageName");
-                    }
                 }
+                echo PHP_EOL;
             }
+        }
 
-            $duration = (int)(microtime(true) - $startTime);
+        $duration = (int)(microtime(true) - $startTime);
-            $mem = (int)(memory_get_usage(true) / (1024 * 1024));
+        $mem = (int)(memory_get_usage(true) / (1024 * 1024));
-            $this->client->window->logMessage(
+        yield from $this->client->window->logMessage(
-                MessageType::INFO,
+            MessageType::INFO,
-                "All $count PHP files parsed in $duration seconds. $mem MiB allocated."
+            "All $count PHP files parsed in $duration seconds. $mem MiB allocated."
-            );
+        );
-        });
     }
 
     /**
      * @param array $files
      * @return Promise
      */
-    private function indexFiles(array $files): Promise
+    private function indexFiles(array $files): \Generator
     {
-        return coroutine(function () use ($files) {
+        foreach ($files as $i => $uri) {
-            foreach ($files as $i => $uri) {
+            // Skip open documents
-                // Skip open documents
+            if ($this->documentLoader->isOpen($uri)) {
-                if ($this->documentLoader->isOpen($uri)) {
+                continue;
-                    continue;
-                }
-
-                // Give LS to the chance to handle requests while indexing
-                yield timeout();
-                $this->client->window->logMessage(MessageType::LOG, "Parsing $uri");
-                try {
-                    $document = yield $this->documentLoader->load($uri);
-                    if (!isVendored($document, $this->composerJson)) {
-                        $this->client->textDocument->publishDiagnostics($uri, $document->getDiagnostics());
-                    }
-                } catch (ContentTooLargeException $e) {
-                    $this->client->window->logMessage(
-                        MessageType::INFO,
-                        "Ignoring file {$uri} because it exceeds size limit of {$e->limit} bytes ({$e->size})"
-                    );
-                } catch (\Exception $e) {
-                    $this->client->window->logMessage(MessageType::ERROR, "Error parsing $uri: " . (string)$e);
-                }
             }
-        });
+
+            // Give LS to the chance to handle requests while indexing
+            yield new Delayed(0);
+            yield from $this->client->window->logMessage(MessageType::LOG, "Parsing $uri");
+            try {
+                $document = yield from $this->documentLoader->load($uri);
+                if (!isVendored($document, $this->composerJson)) {
+                    yield from $this->client->textDocument->publishDiagnostics($uri, $document->getDiagnostics());
+                }
+            } catch (ContentTooLargeException $e) {
+                yield from $this->client->window->logMessage(
+                    MessageType::INFO,
+                    "Ignoring file {$uri} because it exceeds size limit of {$e->limit} bytes ({$e->size})"
+                );
+            } catch (\Exception $e) {
+                yield from $this->client->window->logMessage(MessageType::ERROR, "Error parsing $uri: " . (string)$e);
+            }
+        }
     }
 }

src/LanguageServer.php

@@ -1,24 +1,24 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer;
 
-use LanguageServerProtocol\{
-    ServerCapabilities,
-    ClientCapabilities,
-    TextDocumentSyncKind,
-    InitializeResult,
-    CompletionOptions,
-    SignatureHelpOptions
-};
-use LanguageServer\Message;
-use LanguageServer\FilesFinder\{FilesFinder, ClientFilesFinder, FileSystemFilesFinder};
-use LanguageServer\ContentRetriever\{ContentRetriever, ClientContentRetriever, FileSystemContentRetriever};
-use LanguageServer\Index\{DependenciesIndex, GlobalIndex, Index, ProjectIndex, StubsIndex};
-use LanguageServer\Cache\{FileSystemCache, ClientCache};
 use AdvancedJsonRpc;
-use Sabre\Event\Promise;
+use Amp\Deferred;
-use function Sabre\Event\coroutine;
+use Amp\Delayed;
+use Amp\Loop;
+use Amp\Promise;
+use LanguageServer\Cache\{ClientCache, FileSystemCache};
+use LanguageServer\ContentRetriever\{ClientContentRetriever, ContentRetriever, FileSystemContentRetriever};
+use LanguageServer\Event\MessageEvent;
+use LanguageServer\FilesFinder\{ClientFilesFinder, FilesFinder, FileSystemFilesFinder};
+use LanguageServer\Index\{DependenciesIndex, GlobalIndex, Index, ProjectIndex, StubsIndex};
+use LanguageServerProtocol\{ClientCapabilities,
+    CompletionOptions,
+    InitializeResult,
+    ServerCapabilities,
+    SignatureHelpOptions,
+    TextDocumentSyncKind};
 use Throwable;
 use Webmozart\PathUtil\Path;
 
@@ -38,11 +38,6 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
      */
     public $workspace;
 
-    /**
-     * @var Server\Window
-     */
-    public $window;
-
     public $telemetry;
     public $completionItem;
     public $codeLens;
@@ -107,19 +102,29 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
     protected $definitionResolver;
 
     /**
-     * @param ProtocolReader  $reader
+     * @var Deferred
+     */
+    private $shutdownDeferred;
+
+    /**
+     * @param ProtocolReader $reader
      * @param ProtocolWriter $writer
      */
     public function __construct(ProtocolReader $reader, ProtocolWriter $writer)
     {
         parent::__construct($this, '/');
+
+        $this->shutdownDeferred = new Deferred();
+
         $this->protocolReader = $reader;
-        $this->protocolReader->on('close', function () {
+        $this->protocolReader->addListener('close', function () {
             $this->shutdown();
-            $this->exit();
         });
-        $this->protocolReader->on('message', function (Message $msg) {
+        $this->protocolWriter = $writer;
-            coroutine(function () use ($msg) {
+        $this->client = new LanguageClient($reader, $writer);
+        $this->protocolReader->addListener('message', function (MessageEvent $messageEvent) use ($reader, $writer) {
+            $msg = $messageEvent->getMessage();
+            Loop::defer(function () use ($msg) {
                 // Ignore responses, this is the handler for requests and notifications
                 if (AdvancedJsonRpc\Response::isResponse($msg->body)) {
                     return;
@@ -149,12 +154,15 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
                     } else {
                         $responseBody = new AdvancedJsonRpc\SuccessResponse($msg->body->id, $result);
                     }
-                    $this->protocolWriter->write(new Message($responseBody));
+                    yield from $this->protocolWriter->write(new Message($responseBody));
                 }
-            })->otherwise('\\LanguageServer\\crash');
+            });
         });
-        $this->protocolWriter = $writer;
+    }
-        $this->client = new LanguageClient($reader, $writer);
+
+    public function getshutdownDeferred(): Promise
+    {
+        return $this->shutdownDeferred->promise();
     }
 
     /**
@@ -163,15 +171,13 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
      * @param ClientCapabilities $capabilities The capabilities provided by the client (editor)
      * @param string|null $rootPath The rootPath of the workspace. Is null if no folder is open.
      * @param int|null $processId The process Id of the parent process that started the server. Is null if the process has not been started by another process. If the parent process is not alive then the server should exit (see exit notification) its process.
+     * @param string|null $rootUri
      * @return Promise <InitializeResult>
      */
     public function initialize(ClientCapabilities $capabilities, string $rootPath = null, int $processId = null, string $rootUri = null): Promise
     {
-        if ($rootPath === null && $rootUri !== null) {
+        $deferred = new Deferred();
-            $rootPath = uriToPath($rootUri);
+        Loop::defer(function () use ($deferred, $capabilities, $rootPath, $processId, $rootUri) {
-        }
-        return coroutine(function () use ($capabilities, $rootPath, $processId) {
-
             if ($capabilities->xfilesProvider) {
                 $this->filesFinder = new ClientFilesFinder($this->client);
             } else {
@@ -200,25 +206,25 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
             );
 
             if ($rootPath !== null) {
-                yield $this->beforeIndex($rootPath);
+                yield from $this->beforeIndex($rootPath);
 
                 // Find composer.json
                 if ($this->composerJson === null) {
-                    $composerJsonFiles = yield $this->filesFinder->find(Path::makeAbsolute('**/composer.json', $rootPath));
+                    $composerJsonFiles = yield from $this->filesFinder->find(Path::makeAbsolute('**/composer.json', $rootPath));
                     sortUrisLevelOrder($composerJsonFiles);
 
                     if (!empty($composerJsonFiles)) {
-                        $this->composerJson = json_decode(yield $this->contentRetriever->retrieve($composerJsonFiles[0]));
+                        $this->composerJson = json_decode(yield from $this->contentRetriever->retrieve($composerJsonFiles[0]));
                     }
                 }
 
                 // Find composer.lock
                 if ($this->composerLock === null) {
-                    $composerLockFiles = yield $this->filesFinder->find(Path::makeAbsolute('**/composer.lock', $rootPath));
+                    $composerLockFiles = yield from $this->filesFinder->find(Path::makeAbsolute('**/composer.lock', $rootPath));
                     sortUrisLevelOrder($composerLockFiles);
 
                     if (!empty($composerLockFiles)) {
-                        $this->composerLock = json_decode(yield $this->contentRetriever->retrieve($composerLockFiles[0]));
+                        $this->composerLock = json_decode(yield from $this->contentRetriever->retrieve($composerLockFiles[0]));
                     }
                 }
 
@@ -236,7 +242,9 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
                     $this->composerLock,
                     $this->composerJson
                 );
-                $indexer->index()->otherwise('\\LanguageServer\\crash');
+                Loop::defer(function () use ($indexer) {
+                    yield from $indexer->index();
+                });
             }
 
 
@@ -288,8 +296,9 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
             $serverCapabilities->xdefinitionProvider = true;
             $serverCapabilities->xdependenciesProvider = true;
 
-            return new InitializeResult($serverCapabilities);
+            $deferred->resolve(new InitializeResult($serverCapabilities));
         });
+        return $deferred->promise();
     }
 
     /**
@@ -297,29 +306,23 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
      * (otherwise the response might not be delivered correctly to the client). There is a separate exit notification that
      * asks the server to exit.
      *
-     * @return void
+     * @return \Generator
      */
     public function shutdown()
     {
         unset($this->project);
-    }
+        $this->shutdownDeferred->resolve();
-
+        yield new Delayed(0);
-    /**
-     * A notification to ask the server to exit its process.
-     *
-     * @return void
-     */
-    public function exit()
-    {
-        exit(0);
     }
 
     /**
      * Called before indexing, can return a Promise
      *
      * @param string $rootPath
+     * @return \Generator
      */
     protected function beforeIndex(string $rootPath)
     {
+        yield new Delayed(0, null);
     }
 }

src/Message.php

@@ -1,10 +1,9 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer;
 
 use AdvancedJsonRpc\Message as MessageBody;
-use LanguageServer\Message;
 
 class Message
 {
@@ -27,7 +26,7 @@ class Message
     public static function parse(string $msg): Message
     {
         $obj = new self;
-        $parts = explode("\r\n", $msg);
+        $parts = explode("\r\n\r\n", $msg, 2);
         $obj->body = MessageBody::parse(array_pop($parts));
         foreach ($parts as $line) {
             if ($line) {
@@ -55,11 +54,11 @@ class Message
     {
         $body = (string)$this->body;
         $contentLength = strlen($body);
-        $this->headers['Content-Length'] = $contentLength;
+        $this->headers['Content-Length'] = $contentLength + 6;
         $headers = '';
         foreach ($this->headers as $name => $value) {
             $headers .= "$name: $value\r\n";
         }
-        return $headers . "\r\n" . $body;
+        return $headers . "\r\n" . $body . "\r\n\r\n\r\n";
     }
 }

src/PhpDocument.php

@@ -1,5 +1,5 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer;
 

src/PhpDocumentLoader.php

@@ -1,14 +1,13 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer;
 
 use LanguageServer\ContentRetriever\ContentRetriever;
 use LanguageServer\Index\ProjectIndex;
-use phpDocumentor\Reflection\DocBlockFactory;
-use Sabre\Event\Promise;
-use function Sabre\Event\coroutine;
 use Microsoft\PhpParser;
+use Microsoft\PhpParser\Parser;
+use phpDocumentor\Reflection\DocBlockFactory;
 
 /**
  * Takes care of loading documents and managing "open" documents
@@ -18,7 +17,7 @@ class PhpDocumentLoader
     /**
      * A map from URI => PhpDocument of open documents that should be kept in memory
      *
-     * @var PhpDocument
+     * @var PhpDocument[]
      */
     private $documents = [];
 
@@ -37,11 +36,6 @@ class PhpDocumentLoader
      */
     private $parser;
 
-    /**
-     * @var PhpParser\Parser
-     */
-    private $tolerantParser;
-
     /**
      * @var DocBlockFactory
      */
@@ -87,11 +81,16 @@ class PhpDocumentLoader
      * If the document is not open, loads it.
      *
      * @param string $uri
-     * @return Promise <PhpDocument>
+     * @return \Generator <PhpDocument>
+     * @throws ContentTooLargeException
      */
-    public function getOrLoad(string $uri): Promise
+    public function getOrLoad(string $uri): \Generator
     {
-        return isset($this->documents[$uri]) ? Promise\resolve($this->documents[$uri]) : $this->load($uri);
+        if (isset($this->documents[$uri])) {
+            return $this->documents[$uri];
+        } else {
+            return yield from $this->load($uri);
+        }
     }
 
     /**
@@ -100,27 +99,25 @@ class PhpDocumentLoader
      * The document is NOT added to the list of open documents, but definitions are registered.
      *
      * @param string $uri
-     * @return Promise <PhpDocument>
+     * @return \Generator <PhpDocument>
+     * @throws ContentTooLargeException
      */
-    public function load(string $uri): Promise
+    public function load(string $uri): \Generator
     {
-        return coroutine(function () use ($uri) {
+        $limit = 150000;
+        $content = yield from $this->contentRetriever->retrieve($uri);
+        $size = strlen($content);
+        if ($size > $limit) {
+            throw new ContentTooLargeException($uri, $size, $limit);
+        }
 
-            $limit = 150000;
+        if (isset($this->documents[$uri])) {
-            $content = yield $this->contentRetriever->retrieve($uri);
+            $document = $this->documents[$uri];
-            $size = strlen($content);
+            $document->updateContent($content);
-            if ($size > $limit) {
+        } else {
-                throw new ContentTooLargeException($uri, $size, $limit);
+            $document = $this->create($uri, $content);
-            }
+        }
-
+        return $document;
-            if (isset($this->documents[$uri])) {
-                $document = $this->documents[$uri];
-                $document->updateContent($content);
-            } else {
-                $document = $this->create($uri, $content);
-            }
-            return $document;
-        });
     }
 
     /**
@@ -147,7 +144,7 @@ class PhpDocumentLoader
      *
      * @param string $uri
      * @param string $content
-     * @return void
+     * @return PhpDocument
      */
     public function open(string $uri, string $content)
     {

src/ProtocolReader.php

@@ -1,9 +1,9 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer;
 
-use Sabre\Event\EmitterInterface;
+use League\Event\EmitterInterface;
 
 /**
  * Must emit a "message" event with a Protocol\Message object as parameter

src/ProtocolStreamReader.php

@@ -1,65 +1,54 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer;
 
-use LanguageServer\Message;
 use AdvancedJsonRpc\Message as MessageBody;
-use Sabre\Event\{Loop, Emitter};
+use Amp\ByteStream\InputStream;
+use Amp\Loop;
+use LanguageServer\Event\MessageEvent;
+use League\Event\Emitter;
 
 class ProtocolStreamReader extends Emitter implements ProtocolReader
 {
-    const PARSE_HEADERS = 1;
-    const PARSE_BODY = 2;
-
     private $input;
-    private $parsingMode = self::PARSE_HEADERS;
-    private $buffer = '';
-    private $headers = [];
-    private $contentLength;
 
-    /**
+    public function __construct(InputStream $input)
-     * @param resource $input
-     */
-    public function __construct($input)
     {
         $this->input = $input;
-
+        Loop::defer(function () use (&$input) {
-        $this->on('close', function () {
+            $buffer = '';
-            Loop\removeReadStream($this->input);
+            while (true) {
-        });
+                $headers = [];
-
+                while (true) {
-        Loop\addReadStream($this->input, function () {
+                    while (($pos = strpos($buffer, "\r\n")) === false) {
-            if (feof($this->input)) {
+                        $read = yield $input->read();
-                // If stream_select reported a status change for this stream,
+                        if ($read === null) {
-                // but the stream is EOF, it means it was closed.
+                            return;
-                $this->emit('close');
-                return;
-            }
-            while (($c = fgetc($this->input)) !== false && $c !== '') {
-                $this->buffer .= $c;
-                switch ($this->parsingMode) {
-                    case self::PARSE_HEADERS:
-                        if ($this->buffer === "\r\n") {
-                            $this->parsingMode = self::PARSE_BODY;
-                            $this->contentLength = (int)$this->headers['Content-Length'];
-                            $this->buffer = '';
-                        } else if (substr($this->buffer, -2) === "\r\n") {
-                            $parts = explode(':', $this->buffer);
-                            $this->headers[$parts[0]] = trim($parts[1]);
-                            $this->buffer = '';
-                        }
-                        break;
-                    case self::PARSE_BODY:
-                        if (strlen($this->buffer) === $this->contentLength) {
-                            $msg = new Message(MessageBody::parse($this->buffer), $this->headers);
-                            $this->emit('message', [$msg]);
-                            $this->parsingMode = self::PARSE_HEADERS;
-                            $this->headers = [];
-                            $this->buffer = '';
                         }
+                        $buffer .= $read;
+                    }
+
+                    $headerLine = substr($buffer, 0, $pos);
+                    $buffer = substr($buffer, (int)$pos + 2);
+                    if (!$headerLine) {
                         break;
+                    }
+                    $headerPairs = \explode(': ', $headerLine);
+                    $headers[$headerPairs[0]] = $headerPairs[1];
                 }
+                $contentLength = (int)$headers['Content-Length'];
+                while (strlen($buffer) < $contentLength) {
+                    $read = yield $this->input->read();
+                    if ($read === null) {
+                        return;
+                    }
+                    $buffer .= $read;
+                }
+                $body = substr($buffer, 0, $contentLength);
+                $buffer = substr($buffer, $contentLength);
+                $msg = new Message(MessageBody::parse($body), $headers);
+                $this->emit(new MessageEvent('message', $msg));
             }
         });
     }

src/ProtocolStreamWriter.php

@@ -1,8 +1,9 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer;
 
+use Amp\ByteStream\OutputStream;
 use LanguageServer\Message;
 use Sabre\Event\{
     Loop,
@@ -12,7 +13,7 @@ use Sabre\Event\{
 class ProtocolStreamWriter implements ProtocolWriter
 {
     /**
-     * @var resource $output
+     * @var OutputStream $output
      */
     private $output;
 
@@ -22,9 +23,9 @@ class ProtocolStreamWriter implements ProtocolWriter
     private $messages = [];
 
     /**
-     * @param resource $output
+     * @param OutputStream $output
      */
-    public function __construct($output)
+    public function __construct(OutputStream $output)
     {
         $this->output = $output;
     }
@@ -32,21 +33,9 @@ class ProtocolStreamWriter implements ProtocolWriter
     /**
      * {@inheritdoc}
      */
-    public function write(Message $msg): Promise
+    public function write(Message $msg): \Generator
     {
-        // if the message queue is currently empty, register a write handler.
+        yield $this->output->write((string)$msg);
-        if (empty($this->messages)) {
-            Loop\addWriteStream($this->output, function () {
-                $this->flush();
-            });
-        }
-
-        $promise = new Promise();
-        $this->messages[] = [
-            'message' => (string)$msg,
-            'promise' => $promise
-        ];
-        return $promise;
     }
 
     /**

src/ProtocolWriter.php

@@ -14,5 +14,5 @@ interface ProtocolWriter
      * @param Message $msg
      * @return Promise Resolved when the message has been fully written out to the output stream
      */
-    public function write(Message $msg): Promise;
+    public function write(Message $msg): \Generator;
 }

src/Server/TextDocument.php

@@ -1,37 +1,35 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer\Server;
 
-use LanguageServer\{
+use Amp\Coroutine;
-    CompletionProvider, SignatureHelpProvider, LanguageClient, PhpDocument, PhpDocumentLoader, DefinitionResolver
+use Amp\Deferred;
-};
+use Amp\Loop;
-use LanguageServer\Index\ReadableIndex;
+use Amp\Promise;
+use LanguageServer\{CompletionProvider,
+    DefinitionResolver,
+    LanguageClient,
+    PhpDocument,
+    PhpDocumentLoader,
+    SignatureHelpProvider};
 use LanguageServer\Factory\LocationFactory;
 use LanguageServer\Factory\RangeFactory;
-use LanguageServerProtocol\{
+use LanguageServer\Index\ReadableIndex;
-    FormattingOptions,
+use LanguageServerProtocol\{CompletionContext,
     Hover,
-    Location,
     MarkedString,
+    PackageDescriptor,
     Position,
-    Range,
     ReferenceContext,
     SymbolDescriptor,
-    PackageDescriptor,
     SymbolLocationInformation,
     TextDocumentIdentifier,
     TextDocumentItem,
-    VersionedTextDocumentIdentifier,
+    VersionedTextDocumentIdentifier};
-    CompletionContext
-};
 use Microsoft\PhpParser\Node;
-use Sabre\Event\Promise;
+use function LanguageServer\{getPackageName, isVendored};
-use Sabre\Uri;
+use function League\Uri\parse;
-use function LanguageServer\{
-    isVendored, waitForEvent, getPackageName
-};
-use function Sabre\Event\coroutine;
 
 /**
  * Provides method handlers for all textDocument/* methods
@@ -115,13 +113,18 @@ class TextDocument
      */
     public function documentSymbol(TextDocumentIdentifier $textDocument): Promise
     {
-        return $this->documentLoader->getOrLoad($textDocument->uri)->then(function (PhpDocument $document) {
+        $deferred = new Deferred();
+        Loop::defer(function () use ($textDocument, $deferred) {
+            /** @var PhpDocument $document */
+            $document = yield from $this->documentLoader->getOrLoad($textDocument->uri);
+
             $symbols = [];
             foreach ($document->getDefinitions() as $fqn => $definition) {
                 $symbols[] = $definition->symbolInformation;
             }
-            return $symbols;
+            $deferred->resolve($symbols);
         });
+        return $deferred->promise();
     }
 
     /**
@@ -134,10 +137,12 @@ class TextDocument
      */
     public function didOpen(TextDocumentItem $textDocument)
     {
-        $document = $this->documentLoader->open($textDocument->uri, $textDocument->text);
+        Loop::defer(function () use ($textDocument) {
-        if (!isVendored($document, $this->composerJson)) {
+            $document = $this->documentLoader->open($textDocument->uri, $textDocument->text);
-            $this->client->textDocument->publishDiagnostics($textDocument->uri, $document->getDiagnostics());
+            if (!isVendored($document, $this->composerJson)) {
-        }
+                yield from $this->client->textDocument->publishDiagnostics($textDocument->uri, $document->getDiagnostics());
+            }
+        });
     }
 
     /**
@@ -145,13 +150,18 @@ class TextDocument
      *
      * @param \LanguageServerProtocol\VersionedTextDocumentIdentifier $textDocument
      * @param \LanguageServerProtocol\TextDocumentContentChangeEvent[] $contentChanges
-     * @return void
+     * @return Promise
      */
     public function didChange(VersionedTextDocumentIdentifier $textDocument, array $contentChanges)
     {
-        $document = $this->documentLoader->get($textDocument->uri);
+        $deferred = new Deferred();
-        $document->updateContent($contentChanges[0]->text);
+        Loop::defer(function () use ($deferred, $textDocument, $contentChanges) {
-        $this->client->textDocument->publishDiagnostics($textDocument->uri, $document->getDiagnostics());
+            $document = $this->documentLoader->get($textDocument->uri);
+            $document->updateContent($contentChanges[0]->text);
+            yield from $this->client->textDocument->publishDiagnostics($textDocument->uri, $document->getDiagnostics());
+            $deferred->resolve();
+        });
+        return $deferred->promise();
     }
 
     /**
@@ -179,8 +189,9 @@ class TextDocument
         TextDocumentIdentifier $textDocument,
         Position $position
     ): Promise {
-        return coroutine(function () use ($textDocument, $position) {
+        $deferred = new Deferred();
-            $document = yield $this->documentLoader->getOrLoad($textDocument->uri);
+        Loop::defer(function () use ($deferred, $textDocument, $position) {
+            $document = yield from $this->documentLoader->getOrLoad($textDocument->uri);
             $node = $document->getNodeAtPosition($position);
             if ($node === null) {
                 return [];
@@ -189,8 +200,7 @@ class TextDocument
             // Variables always stay in the boundary of the file and need to be searched inside their function scope
             // by traversing the AST
             if (
-
+                ($node instanceof Node\Expression\Variable && !($node->getParent()->getParent() instanceof Node\PropertyDeclaration))
-            ($node instanceof Node\Expression\Variable && !($node->getParent()->getParent() instanceof Node\PropertyDeclaration))
                 || $node instanceof Node\Parameter
                 || $node instanceof Node\UseVariableName
             ) {
@@ -217,21 +227,18 @@ class TextDocument
                 // Definition with a global FQN
                 $fqn = DefinitionResolver::getDefinedFqn($node);
 
-                // Wait until indexing finished
-                if (!$this->index->isComplete()) {
-                    yield waitForEvent($this->index, 'complete');
-                }
                 if ($fqn === null) {
                     $fqn = $this->definitionResolver->resolveReferenceNodeToFqn($node);
                     if ($fqn === null) {
-                        return [];
+                        $deferred->resolve([]);
+                        return;
                     }
                 }
                 $refDocumentPromises = [];
                 foreach ($this->index->getReferenceUris($fqn) as $uri) {
-                    $refDocumentPromises[] = $this->documentLoader->getOrLoad($uri);
+                    $refDocumentPromises[] = new Coroutine($this->documentLoader->getOrLoad($uri));
                 }
-                $refDocuments = yield Promise\all($refDocumentPromises);
+                $refDocuments = yield \Amp\Promise\all($refDocumentPromises);
                 foreach ($refDocuments as $document) {
                     $refs = $document->getReferenceNodesByFqn($fqn);
                     if ($refs !== null) {
@@ -241,8 +248,9 @@ class TextDocument
                     }
                 }
             }
-            return $locations;
+            $deferred->resolve($locations);
         });
+        return $deferred->promise();
     }
 
     /**
@@ -250,16 +258,20 @@ class TextDocument
      * cursor position.
      *
      * @param TextDocumentIdentifier $textDocument The text document
-     * @param Position               $position     The position inside the text document
+     * @param Position $position The position inside the text document
      *
      * @return Promise <SignatureHelp>
      */
     public function signatureHelp(TextDocumentIdentifier $textDocument, Position $position): Promise
     {
-        return coroutine(function () use ($textDocument, $position) {
+        $deferred = new Deferred();
-            $document = yield $this->documentLoader->getOrLoad($textDocument->uri);
+        Loop::defer(function () use ($deferred, $textDocument, $position) {
-            return $this->signatureHelpProvider->getSignatureHelp($document, $position);
+            $document = yield from $this->documentLoader->getOrLoad($textDocument->uri);
+            $deferred->resolve(
+                yield from $this->signatureHelpProvider->getSignatureHelp($document, $position)
+            );
         });
+        return $deferred->promise();
     }
 
     /**
@@ -269,11 +281,13 @@ class TextDocument
      * @param TextDocumentIdentifier $textDocument The text document
      * @param Position $position The position inside the text document
      * @return Promise <Location|Location[]>
+     * @throws \LanguageServer\ContentTooLargeException
      */
     public function definition(TextDocumentIdentifier $textDocument, Position $position): Promise
     {
-        return coroutine(function () use ($textDocument, $position) {
+        $deferred = new Deferred();
-            $document = yield $this->documentLoader->getOrLoad($textDocument->uri);
+        Loop::defer(function () use ($deferred, $textDocument, $position) {
+            $document = yield from $this->documentLoader->getOrLoad($textDocument->uri);
             $node = $document->getNodeAtPosition($position);
             if ($node === null) {
                 return [];
@@ -291,17 +305,18 @@ class TextDocument
                 if ($def !== null || $this->index->isComplete()) {
                     break;
                 }
-                yield waitForEvent($this->index, 'definition-added');
             }
             if (
                 $def === null
                 || $def->symbolInformation === null
-                || Uri\parse($def->symbolInformation->location->uri)['scheme'] === 'phpstubs'
+                || parse($def->symbolInformation->location->uri)['scheme'] === 'phpstubs'
             ) {
-                return [];
+                $deferred->resolve([]);
+            } else {
+                $deferred->resolve($def->symbolInformation->location);
             }
-            return $def->symbolInformation->location;
         });
+        return $deferred->promise();
     }
 
     /**
@@ -313,8 +328,9 @@ class TextDocument
      */
     public function hover(TextDocumentIdentifier $textDocument, Position $position): Promise
     {
-        return coroutine(function () use ($textDocument, $position) {
+        $deferred = new Deferred();
-            $document = yield $this->documentLoader->getOrLoad($textDocument->uri);
+        Loop::defer(function () use ($deferred, $textDocument, $position) {
+            $document = yield from $this->documentLoader->getOrLoad($textDocument->uri);
             // Find the node under the cursor
             $node = $document->getNodeAtPosition($position);
             if ($node === null) {
@@ -333,7 +349,6 @@ class TextDocument
                 if ($def !== null || $this->index->isComplete()) {
                     break;
                 }
-                yield waitForEvent($this->index, 'definition-added');
             }
             $range = RangeFactory::fromNode($node);
             if ($def === null) {
@@ -346,8 +361,9 @@ class TextDocument
             if ($def->documentation) {
                 $contents[] = $def->documentation;
             }
-            return new Hover($contents, $range);
+            $deferred->resolve(new Hover($contents, $range));
         });
+        return $deferred->promise();
     }
 
     /**
@@ -360,17 +376,20 @@ class TextDocument
      * interface then a 'completionItem/resolve' request is sent with the selected completion item as a param. The
      * returned completion item should have the documentation property filled in.
      *
-     * @param TextDocumentIdentifier The text document
+     * @param TextDocumentIdentifier $textDocument
      * @param Position $position The position
      * @param CompletionContext|null $context The completion context
      * @return Promise <CompletionItem[]|CompletionList>
      */
     public function completion(TextDocumentIdentifier $textDocument, Position $position, CompletionContext $context = null): Promise
     {
-        return coroutine(function () use ($textDocument, $position, $context) {
+        $deferred = new Deferred();
-            $document = yield $this->documentLoader->getOrLoad($textDocument->uri);
+        Loop::defer(function () use ($deferred, $context, $position, $textDocument) {
-            return $this->completionProvider->provideCompletion($document, $position, $context);
+            /** @var PhpDocument $document */
+            $document = yield from $this->documentLoader->getOrLoad($textDocument->uri);
+            $deferred->resolve($this->completionProvider->provideCompletion($document, $position, $context));
         });
+        return $deferred->promise();
     }
 
     /**
@@ -382,12 +401,13 @@ class TextDocument
      * but still may know some information about it.
      *
      * @param TextDocumentIdentifier $textDocument The text document
-     * @param Position               $position     The position inside the text document
+     * @param Position $position The position inside the text document
      * @return Promise <SymbolLocationInformation[]>
      */
     public function xdefinition(TextDocumentIdentifier $textDocument, Position $position): Promise
     {
-        return coroutine(function () use ($textDocument, $position) {
+        $deferred = new Deferred();
+        Loop::defer(function () use ($deferred, $textDocument, $position) {
             $document = yield $this->documentLoader->getOrLoad($textDocument->uri);
             $node = $document->getNodeAtPosition($position);
             if ($node === null) {
@@ -406,12 +426,11 @@ class TextDocument
                 if ($def !== null || $this->index->isComplete()) {
                     break;
                 }
-                yield waitForEvent($this->index, 'definition-added');
             }
             if (
                 $def === null
                 || $def->symbolInformation === null
-                || Uri\parse($def->symbolInformation->location->uri)['scheme'] === 'phpstubs'
+                || parse($def->symbolInformation->location->uri)['scheme'] === 'phpstubs'
             ) {
                 return [];
             }
@@ -422,7 +441,8 @@ class TextDocument
                 $packageName = $this->composerJson->name;
             }
             $descriptor = new SymbolDescriptor($def->fqn, new PackageDescriptor($packageName));
-            return [new SymbolLocationInformation($descriptor, $def->symbolInformation->location)];
+            $deferred->resolve([new SymbolLocationInformation($descriptor, $def->symbolInformation->location)]);
         });
+        return $deferred->promise();
     }
 }

src/Server/Workspace.php

@@ -1,23 +1,17 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer\Server;
 
+use Amp\Deferred;
+use Amp\Delayed;
+use Amp\Loop;
+use Amp\Promise;
+use Amp\Success;
 use LanguageServer\{LanguageClient, PhpDocumentLoader};
-use LanguageServer\Index\{ProjectIndex, DependenciesIndex, Index};
 use LanguageServer\Factory\LocationFactory;
-use LanguageServerProtocol\{
+use LanguageServer\Index\{DependenciesIndex, Index, ProjectIndex};
-    FileChangeType,
+use LanguageServerProtocol\{DependencyReference, FileChangeType, FileEvent, ReferenceInformation, SymbolDescriptor};
-    FileEvent,
-    SymbolInformation,
-    SymbolDescriptor,
-    ReferenceInformation,
-    DependencyReference,
-    Location
-};
-use Sabre\Event\Promise;
-use function Sabre\Event\coroutine;
-use function LanguageServer\waitForEvent;
 
 /**
  * Provides method handlers for all workspace/* methods
@@ -57,12 +51,12 @@ class Workspace
     public $documentLoader;
 
     /**
-     * @param LanguageClient    $client            LanguageClient instance used to signal updated results
+     * @param LanguageClient $client LanguageClient instance used to signal updated results
-     * @param ProjectIndex      $projectIndex      Index that is used to wait for full index completeness
+     * @param ProjectIndex $projectIndex Index that is used to wait for full index completeness
      * @param DependenciesIndex $dependenciesIndex Index that is used on a workspace/xreferences request
-     * @param DependenciesIndex $sourceIndex       Index that is used on a workspace/xreferences request
+     * @param DependenciesIndex $sourceIndex Index that is used on a workspace/xreferences request
-     * @param \stdClass         $composerLock      The parsed composer.lock of the project, if any
+     * @param \stdClass $composerLock The parsed composer.lock of the project, if any
-     * @param PhpDocumentLoader $documentLoader    PhpDocumentLoader instance to load documents
+     * @param PhpDocumentLoader $documentLoader PhpDocumentLoader instance to load documents
      */
     public function __construct(LanguageClient $client, ProjectIndex $projectIndex, DependenciesIndex $dependenciesIndex, Index $sourceIndex, \stdClass $composerLock = null, PhpDocumentLoader $documentLoader, \stdClass $composerJson = null)
     {
@@ -83,19 +77,13 @@ class Workspace
      */
     public function symbol(string $query): Promise
     {
-        return coroutine(function () use ($query) {
+        $symbols = [];
-            // Wait until indexing for definitions finished
+        foreach ($this->sourceIndex->getDefinitions() as $fqn => $definition) {
-            if (!$this->sourceIndex->isStaticComplete()) {
+            if ($query === '' || stripos($fqn, $query) !== false) {
-                yield waitForEvent($this->sourceIndex, 'static-complete');
+                $symbols[] = $definition->symbolInformation;
             }
-            $symbols = [];
+        }
-            foreach ($this->sourceIndex->getDefinitions() as $fqn => $definition) {
+        return new Success($symbols);
-                if ($query === '' || stripos($fqn, $query) !== false) {
-                    $symbols[] = $definition->symbolInformation;
-                }
-            }
-            return $symbols;
-        });
     }
 
     /**
@@ -106,35 +94,35 @@ class Workspace
      */
     public function didChangeWatchedFiles(array $changes)
     {
-        foreach ($changes as $change) {
+        Loop::defer(function () use ($changes) {
-            if ($change->type === FileChangeType::DELETED) {
+            foreach ($changes as $change) {
-                $this->client->textDocument->publishDiagnostics($change->uri, []);
+                if ($change->type === FileChangeType::DELETED) {
+                    yield from $this->client->textDocument->publishDiagnostics($change->uri, []);
+                }
             }
-        }
+        });
     }
 
     /**
      * The workspace references request is sent from the client to the server to locate project-wide references to a symbol given its description / metadata.
      *
      * @param SymbolDescriptor $query Partial metadata about the symbol that is being searched for.
-     * @param string[]         $files An optional list of files to restrict the search to.
+     * @param string[] $files An optional list of files to restrict the search to.
-     * @return ReferenceInformation[]
+     * @return \Generator
+     * @throws \LanguageServer\ContentTooLargeException
      */
-    public function xreferences($query, array $files = null): Promise
+    public function xreferences($query, array $files = null): \Generator
     {
-        // TODO: $files is unused in the coroutine
+        $deferred = new Deferred();
-        return coroutine(function () use ($query, $files) {
+        Loop::defer(function () use ($deferred, $query, $files) {
+            // TODO: $files is unused in the coroutine
             if ($this->composerLock === null) {
                 return [];
             }
-            // Wait until indexing finished
-            if (!$this->projectIndex->isComplete()) {
-                yield waitForEvent($this->projectIndex, 'complete');
-            }
             /** Map from URI to array of referenced FQNs in dependencies */
             $refs = [];
             // Get all references TO dependencies
-            $fqns = isset($query->fqsen) ? [$query->fqsen] : array_values($this->dependenciesIndex->getDefinitions());
+            $fqns = isset($query->fqsen) ? [$query->fqsen] : array_values(yield from $this->dependenciesIndex->getDefinitions());
             foreach ($fqns as $fqn) {
                 foreach ($this->sourceIndex->getReferenceUris($fqn) as $uri) {
                     if (!isset($refs[$uri])) {
@@ -148,7 +136,7 @@ class Workspace
             $refInfos = [];
             foreach ($refs as $uri => $fqns) {
                 foreach ($fqns as $fqn) {
-                    $doc = yield $this->documentLoader->getOrLoad($uri);
+                    $doc = yield from $this->documentLoader->getOrLoad($uri);
                     foreach ($doc->getReferenceNodesByFqn($fqn) as $node) {
                         $refInfo = new ReferenceInformation;
                         $refInfo->reference = LocationFactory::fromNode($node);
@@ -157,8 +145,9 @@ class Workspace
                     }
                 }
             }
-            return $refInfos;
+            $deferred->resolve($refInfos);
         });
+        return $deferred->promise();
     }
 
     /**

src/SignatureHelpProvider.php

@@ -1,16 +1,13 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer;
 
+use Amp\Delayed;
 use LanguageServer\Index\ReadableIndex;
-use LanguageServerProtocol\{
+use LanguageServerProtocol\{Position, SignatureHelp};
-    Position,
-    SignatureHelp
-};
 use Microsoft\PhpParser\Node;
 use Sabre\Event\Promise;
-use function Sabre\Event\coroutine;
 
 class SignatureHelpProvider
 {
@@ -27,8 +24,8 @@ class SignatureHelpProvider
      * Constructor
      *
      * @param DefinitionResolver $definitionResolver
-     * @param ReadableIndex      $index
+     * @param ReadableIndex $index
-     * @param PhpDocumentLoader  $documentLoader
+     * @param PhpDocumentLoader $documentLoader
      */
     public function __construct(DefinitionResolver $definitionResolver, ReadableIndex $index, PhpDocumentLoader $documentLoader)
     {
@@ -40,31 +37,29 @@ class SignatureHelpProvider
     /**
      * Finds signature help for a callable position
      *
-     * @param PhpDocument $doc      The document the position belongs to
+     * @param PhpDocument $doc The document the position belongs to
-     * @param Position    $position The position to detect a call from
+     * @param Position $position The position to detect a call from
      *
      * @return Promise <SignatureHelp>
      */
-    public function getSignatureHelp(PhpDocument $doc, Position $position): Promise
+    public function getSignatureHelp(PhpDocument $doc, Position $position): \Generator
     {
-        return coroutine(function () use ($doc, $position) {
+        // Find the node under the cursor
-            // Find the node under the cursor
+        $node = $doc->getNodeAtPosition($position);
-            $node = $doc->getNodeAtPosition($position);
 
-            // Find the definition of the item being called
+        // Find the definition of the item being called
-            list($def, $argumentExpressionList) = yield $this->getCallingInfo($node);
+        list($def, $argumentExpressionList) = yield from $this->getCallingInfo($node);
 
-            if (!$def || !$def->signatureInformation) {
+        if (!$def || !$def->signatureInformation) {
-                return new SignatureHelp();
+            return new SignatureHelp();
-            }
+        }
 
-            // Find the active parameter
+        // Find the active parameter
-            $activeParam = $argumentExpressionList
+        $activeParam = $argumentExpressionList
-                ? $this->findActiveParameter($argumentExpressionList, $position, $doc)
+            ? $this->findActiveParameter($argumentExpressionList, $position, $doc)
-                : 0;
+            : 0;
 
-            return new SignatureHelp([$def->signatureInformation], 0, $activeParam);
+        return new SignatureHelp([$def->signatureInformation], 0, $activeParam);
-        });
     }
 
     /**
@@ -73,83 +68,81 @@ class SignatureHelpProvider
      *
      * @param Node $node The node to find calling information from
      *
-     * @return Promise <array|null>
+     * @return \Generator <array|null>
      */
-    private function getCallingInfo(Node $node)
+    private function getCallingInfo(Node $node): \Generator
     {
-        return coroutine(function () use ($node) {
+        $fqn = null;
-            $fqn = null;
+        $callingNode = null;
-            $callingNode = null;
+        if ($node instanceof Node\DelimitedList\ArgumentExpressionList) {
-            if ($node instanceof Node\DelimitedList\ArgumentExpressionList) {
+            // Cursor is already inside a (
-                // Cursor is already inside a (
+            $argumentExpressionList = $node;
-                $argumentExpressionList = $node;
+            if ($node->parent instanceof Node\Expression\ObjectCreationExpression) {
-                if ($node->parent instanceof Node\Expression\ObjectCreationExpression) {
+                // Constructing something
-                    // Constructing something
+                $callingNode = $node->parent->classTypeDesignator;
-                    $callingNode = $node->parent->classTypeDesignator;
-                    if (!$callingNode instanceof Node\QualifiedName) {
-                        // We only support constructing from a QualifiedName
-                        return null;
-                    }
-                    $fqn = $this->definitionResolver->resolveReferenceNodeToFqn($callingNode);
-                    $fqn = "{$fqn}->__construct()";
-                } else {
-                    $callingNode = $node->parent->getFirstChildNode(
-                        Node\Expression\MemberAccessExpression::class,
-                        Node\Expression\ScopedPropertyAccessExpression::class,
-                        Node\QualifiedName::class
-                    );
-                }
-            } elseif ($node instanceof Node\Expression\CallExpression) {
-                $argumentExpressionList = $node->getFirstChildNode(Node\DelimitedList\ArgumentExpressionList::class);
-                $callingNode = $node->getFirstChildNode(
-                    Node\Expression\MemberAccessExpression::class,
-                    Node\Expression\ScopedPropertyAccessExpression::class,
-                    Node\QualifiedName::class
-                );
-            } elseif ($node instanceof Node\Expression\ObjectCreationExpression) {
-                $argumentExpressionList = $node->getFirstChildNode(Node\DelimitedList\ArgumentExpressionList::class);
-                $callingNode = $node->classTypeDesignator;
                 if (!$callingNode instanceof Node\QualifiedName) {
                     // We only support constructing from a QualifiedName
                     return null;
                 }
-                // Manually build the __construct fqn
                 $fqn = $this->definitionResolver->resolveReferenceNodeToFqn($callingNode);
                 $fqn = "{$fqn}->__construct()";
+            } else {
+                $callingNode = $node->parent->getFirstChildNode(
+                    Node\Expression\MemberAccessExpression::class,
+                    Node\Expression\ScopedPropertyAccessExpression::class,
+                    Node\QualifiedName::class
+                );
             }
-
+        } elseif ($node instanceof Node\Expression\CallExpression) {
-            if (!$callingNode) {
+            $argumentExpressionList = $node->getFirstChildNode(Node\DelimitedList\ArgumentExpressionList::class);
+            $callingNode = $node->getFirstChildNode(
+                Node\Expression\MemberAccessExpression::class,
+                Node\Expression\ScopedPropertyAccessExpression::class,
+                Node\QualifiedName::class
+            );
+        } elseif ($node instanceof Node\Expression\ObjectCreationExpression) {
+            $argumentExpressionList = $node->getFirstChildNode(Node\DelimitedList\ArgumentExpressionList::class);
+            $callingNode = $node->classTypeDesignator;
+            if (!$callingNode instanceof Node\QualifiedName) {
+                // We only support constructing from a QualifiedName
                 return null;
             }
+            // Manually build the __construct fqn
+            $fqn = $this->definitionResolver->resolveReferenceNodeToFqn($callingNode);
+            $fqn = "{$fqn}->__construct()";
+        }
 
-            // Now find the definition of the call
+        if (!$callingNode) {
-            $fqn = $fqn ?: DefinitionResolver::getDefinedFqn($callingNode);
+            return null;
-            while (true) {
+        }
-                if ($fqn) {
+
-                    $def = $this->index->getDefinition($fqn);
+        // Now find the definition of the call
-                } else {
+        $fqn = $fqn ?: DefinitionResolver::getDefinedFqn($callingNode);
-                    $def = $this->definitionResolver->resolveReferenceNodeToDefinition($callingNode);
+        while (true) {
-                }
+            if ($fqn) {
-                if ($def !== null || $this->index->isComplete()) {
+                $def = $this->index->getDefinition($fqn);
-                    break;
+            } else {
-                }
+                $def = $this->definitionResolver->resolveReferenceNodeToDefinition($callingNode);
-                yield waitForEvent($this->index, 'definition-added');
             }
-
+            if ($def !== null || $this->index->isComplete()) {
-            if (!$def) {
+                break;
-                return null;
             }
+        }
 
-            return [$def, $argumentExpressionList];
+        if (!$def) {
-        });
+            return null;
+        }
+
+        yield new Delayed(0);
+        return [$def, $argumentExpressionList];
     }
 
     /**
      * Given a position and arguments, finds the "active" argument at the position
      *
      * @param Node\DelimitedList\ArgumentExpressionList $argumentExpressionList The argument expression list
-     * @param Position                                  $position               The position to detect the active argument from
+     * @param Position $position The position to detect the active argument from
-     * @param PhpDocument                               $doc                    The document that contains the expression
+     * @param PhpDocument $doc The document that contains the expression
      *
      * @return int
      */

src/utils.php

@@ -1,12 +1,12 @@
 <?php
-declare(strict_types = 1);
+declare(strict_types=1);
 
 namespace LanguageServer;
 
-use Throwable;
+use Amp\Loop;
 use InvalidArgumentException;
-use Sabre\Event\{Loop, Promise, EmitterInterface};
+use Throwable;
-use Sabre\Uri;
+use function League\Uri\parse;
 
 /**
  * Transforms an absolute file path into a URI as used by the language server protocol.
@@ -60,39 +60,11 @@ function uriToPath(string $uri)
  */
 function crash(Throwable $err)
 {
-    Loop\nextTick(function () use ($err) {
+    Loop::run(function () use ($err) {
         throw $err;
     });
 }
 
-/**
- * Returns a promise that is resolved after x seconds.
- * Useful for giving back control to the event loop inside a coroutine.
- *
- * @param int $seconds
- * @return Promise <void>
- */
-function timeout($seconds = 0): Promise
-{
-    $promise = new Promise;
-    Loop\setTimeout([$promise, 'fulfill'], $seconds);
-    return $promise;
-}
-
-/**
- * Returns a promise that is fulfilled once the passed event was triggered on the passed EventEmitter
- *
- * @param EmitterInterface $emitter
- * @param string           $event
- * @return Promise
- */
-function waitForEvent(EmitterInterface $emitter, string $event): Promise
-{
-    $p = new Promise;
-    $emitter->once($event, [$p, 'fulfill']);
-    return $p;
-}
-
 /**
  * Returns the part of $b that is not overlapped by $a
  * Example:
@@ -125,7 +97,7 @@ function stripStringOverlap(string $a, string $b): string
 function sortUrisLevelOrder(&$uriList)
 {
     usort($uriList, function ($a, $b) {
-        return substr_count(Uri\parse($a)['path'], '/') - substr_count(Uri\parse($b)['path'], '/');
+        return substr_count(parse($a)['path'], '/') - substr_count(parse($b)['path'], '/');
     });
 }
 
@@ -133,13 +105,13 @@ function sortUrisLevelOrder(&$uriList)
  * Checks a document against the composer.json to see if it
  * is a vendored document
  *
- * @param PhpDocument    $document
+ * @param PhpDocument $document
  * @param \stdClass|null $composerJson
  * @return bool
  */
 function isVendored(PhpDocument $document, \stdClass $composerJson = null): bool
 {
-    $path = Uri\parse($document->getUri())['path'];
+    $path = parse($document->getUri())['path'];
     $vendorDir = getVendorDir($composerJson);
     return strpos($path, "/$vendorDir/") !== false;
 }
@@ -148,7 +120,7 @@ function isVendored(PhpDocument $document, \stdClass $composerJson = null): bool
  * Check a given URI against the composer.json to see if it
  * is a vendored URI
  *
- * @param string         $uri
+ * @param string $uri
  * @param \stdClass|null $composerJson
  * @return string|null
  */