diff --git a/README.md b/README.md
index e608a77..3e753ac 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,6 @@
 [![Linux Build Status](https://travis-ci.org/felixfbecker/php-language-server.svg?branch=master)](https://travis-ci.org/felixfbecker/php-language-server)
 [![Windows Build status](https://ci.appveyor.com/api/projects/status/2sp5ll052wdjqmdm/branch/master?svg=true)](https://ci.appveyor.com/project/felixfbecker/php-language-server/branch/master)
 [![Coverage](https://codecov.io/gh/felixfbecker/php-language-server/branch/master/graph/badge.svg)](https://codecov.io/gh/felixfbecker/php-language-server)
-[![Dependency Status](https://gemnasium.com/badges/github.com/felixfbecker/php-language-server.svg)](https://gemnasium.com/github.com/felixfbecker/php-language-server)
 [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg)](https://github.com/semantic-release/semantic-release)
 [![Minimum PHP Version](https://img.shields.io/badge/php-%3E%3D%207.0-8892BF.svg)](https://php.net/)
 [![License](https://img.shields.io/packagist/l/felixfbecker/language-server.svg)](https://github.com/felixfbecker/php-language-server/blob/master/LICENSE.txt)
diff --git a/benchmarks/completion.php b/benchmarks/completion.php
new file mode 100644
index 0000000..2e736d7
--- /dev/null
+++ b/benchmarks/completion.php
@@ -0,0 +1,89 @@
+<?php
+
+namespace LanguageServer\Tests;
+require __DIR__ . '/../vendor/autoload.php';
+
+use Composer\XdebugHandler\XdebugHandler;
+use Exception;
+use LanguageServer\CompletionProvider;
+use LanguageServer\DefinitionResolver;
+use LanguageServer\Index\Index;
+use LanguageServer\PhpDocument;
+use LanguageServer\StderrLogger;
+use LanguageServerProtocol\Position;
+use Microsoft\PhpParser;
+use phpDocumentor\Reflection\DocBlockFactory;
+use RecursiveDirectoryIterator;
+use RecursiveIteratorIterator;
+
+$logger = new StderrLogger();
+$xdebugHandler = new XdebugHandler('PHPLS');
+$xdebugHandler->setLogger($logger);
+$xdebugHandler->check();
+unset($xdebugHandler);
+
+$totalSize = 0;
+
+$framework = "symfony";
+
+$iterator = new RecursiveDirectoryIterator(__DIR__ . "/../validation/frameworks/$framework");
+$testProviderArray = array();
+
+foreach (new RecursiveIteratorIterator($iterator) as $file) {
+    if (strpos((string)$file, ".php") !== false) {
+        $totalSize += $file->getSize();
+        $testProviderArray[] = $file->getRealPath();
+    }
+}
+
+if (count($testProviderArray) === 0) {
+    throw new Exception("ERROR: Validation testsuite frameworks not found - run `git submodule update --init --recursive` to download.");
+}
+
+$index = new Index;
+$definitionResolver = new DefinitionResolver($index);
+$completionProvider = new CompletionProvider($definitionResolver, $index);
+$docBlockFactory = DocBlockFactory::createInstance();
+$completionFile = realpath(__DIR__ . '/../validation/frameworks/symfony/src/Symfony/Component/HttpFoundation/Request.php');
+$parser = new PhpParser\Parser();
+$completionDocument = null;
+
+echo "Indexing $framework" . PHP_EOL;
+
+foreach ($testProviderArray as $idx => $testCaseFile) {
+    if (filesize($testCaseFile) > 100000) {
+        continue;
+    }
+    if ($idx % 100 === 0) {
+        echo $idx . '/' . count($testProviderArray) . PHP_EOL;
+    }
+
+    $fileContents = file_get_contents($testCaseFile);
+
+    try {
+        $d = new PhpDocument($testCaseFile, $fileContents, $index, $parser, $docBlockFactory, $definitionResolver);
+        if ($testCaseFile === $completionFile) {
+            $completionDocument = $d;
+        }
+    } catch (\Throwable $e) {
+        echo $e->getMessage() . PHP_EOL;
+        continue;
+    }
+}
+
+echo "Getting completion". PHP_EOL;
+
+// Completion in $this->|request = new ParameterBag($request);
+$start = microtime(true);
+$list = $completionProvider->provideCompletion($completionDocument, new Position(274, 15));
+$end = microtime(true);
+echo 'Time ($this->|): ' . ($end - $start) . 's' . PHP_EOL;
+echo count($list->items) . ' completion items' . PHP_EOL;
+
+// Completion in $this->request = new| ParameterBag($request);
+// (this only finds ParameterBag though.)
+$start = microtime(true);
+$list = $completionProvider->provideCompletion($completionDocument, new Position(274, 28));
+$end = microtime(true);
+echo 'Time (new|): ' . ($end - $start) . 's' . PHP_EOL;
+echo count($list->items) . ' completion items' . PHP_EOL;
diff --git a/Performance.php b/benchmarks/parsing.php
similarity index 77%
rename from Performance.php
rename to benchmarks/parsing.php
index 4d76d38..516de40 100644
--- a/Performance.php
+++ b/benchmarks/parsing.php
@@ -1,23 +1,31 @@
 <?php
 
 namespace LanguageServer\Tests;
-require __DIR__ . '/vendor/autoload.php';
+require __DIR__ . '/../vendor/autoload.php';
 
+use Composer\XdebugHandler\XdebugHandler;
 use Exception;
+use LanguageServer\DefinitionResolver;
 use LanguageServer\Index\Index;
 use LanguageServer\PhpDocument;
-use LanguageServer\DefinitionResolver;
+use LanguageServer\StderrLogger;
 use Microsoft\PhpParser;
 use phpDocumentor\Reflection\DocBlockFactory;
 use RecursiveDirectoryIterator;
 use RecursiveIteratorIterator;
 
+$logger = new StderrLogger();
+$xdebugHandler = new XdebugHandler('PHPLS');
+$xdebugHandler->setLogger($logger);
+$xdebugHandler->check();
+unset($xdebugHandler);
+
 $totalSize = 0;
 
 $frameworks = ["drupal", "wordpress", "php-language-server", "tolerant-php-parser", "math-php", "symfony", "codeigniter", "cakephp"];
 
 foreach($frameworks as $framework) {
-    $iterator = new RecursiveDirectoryIterator(__DIR__ . "/validation/frameworks/$framework");
+    $iterator = new RecursiveDirectoryIterator(__DIR__ . "/../validation/frameworks/$framework");
     $testProviderArray = array();
 
     foreach (new RecursiveIteratorIterator($iterator) as $file) {
@@ -37,8 +45,8 @@ foreach($frameworks as $framework) {
         if (filesize($testCaseFile) > 10000) {
             continue;
         }
-        if ($idx % 1000 === 0) {
-            echo "$idx\n";
+        if ($idx % 500 === 0) {
+            echo $idx . '/' . count($testProviderArray) . PHP_EOL;
         }
 
         $fileContents = file_get_contents($testCaseFile);
diff --git a/composer.json b/composer.json
index 085f189..ffa5971 100644
--- a/composer.json
+++ b/composer.json
@@ -24,6 +24,7 @@
         "php": "^7.0",
         "composer/xdebug-handler": "^1.0",
         "felixfbecker/advanced-json-rpc": "^3.0.0",
+        "felixfbecker/language-server-protocol": "^1.0.1",
         "jetbrains/phpstorm-stubs": "dev-master",
         "microsoft/tolerant-php-parser": "0.0.*",
         "netresearch/jsonmapper": "^1.0",
diff --git a/fixtures/completion/used_namespace.php b/fixtures/completion/used_namespace.php
new file mode 100644
index 0000000..40a7e50
--- /dev/null
+++ b/fixtures/completion/used_namespace.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace Whatever;
+
+use TestNamespace\InnerNamespace as AliasNamespace;
+
+class IDontShowUpInCompletion {}
+
+AliasNamespace\I;
+AliasNamespace\;
diff --git a/fixtures/self_referencing_class.php b/fixtures/self_referencing_class.php
new file mode 100644
index 0000000..06dc8f0
--- /dev/null
+++ b/fixtures/self_referencing_class.php
@@ -0,0 +1,20 @@
+<?php
+namespace RecursiveTest;
+
+class A extends A {}
+
+class B extends C {}
+class C extends B {}
+
+class D extends E {}
+class E extends F {}
+class F extends D {}
+
+$a = new A;
+$a->undef_prop = 1;
+
+$b = new B;
+$b->undef_prop = 1;
+
+$d = new D;
+$d->undef_prop = 1;
diff --git a/fixtures/symbols.php b/fixtures/symbols.php
index 4e9b0d4..7f5c2fb 100644
--- a/fixtures/symbols.php
+++ b/fixtures/symbols.php
@@ -103,3 +103,8 @@ class Example {
     public function __construct() {}
     public function __destruct() {}
 }
+
+namespace TestNamespace\InnerNamespace;
+
+class InnerClass {
+}
diff --git a/package-lock.json b/package-lock.json
index fd26f34..fae7b60 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,8 +1,6 @@
 {
-  "name": "php-language-server",
-  "version": "0.0.0-development",
-  "lockfileVersion": 1,
   "requires": true,
+  "lockfileVersion": 1,
   "dependencies": {
     "@gimenete/type-writer": {
       "version": "0.1.3",
diff --git a/src/Client/TextDocument.php b/src/Client/TextDocument.php
index 1e65995..03211fa 100644
--- a/src/Client/TextDocument.php
+++ b/src/Client/TextDocument.php
@@ -4,7 +4,7 @@ declare(strict_types = 1);
 namespace LanguageServer\Client;
 
 use LanguageServer\ClientHandler;
-use LanguageServer\Protocol\{Diagnostic, TextDocumentItem, TextDocumentIdentifier};
+use LanguageServerProtocol\{Diagnostic, TextDocumentItem, TextDocumentIdentifier};
 use Sabre\Event\Promise;
 use JsonMapper;
 
diff --git a/src/Client/Workspace.php b/src/Client/Workspace.php
index 901e386..8c31f1f 100644
--- a/src/Client/Workspace.php
+++ b/src/Client/Workspace.php
@@ -4,7 +4,7 @@ declare(strict_types = 1);
 namespace LanguageServer\Client;
 
 use LanguageServer\ClientHandler;
-use LanguageServer\Protocol\TextDocumentIdentifier;
+use LanguageServerProtocol\TextDocumentIdentifier;
 use Sabre\Event\Promise;
 use JsonMapper;
 
diff --git a/src/ClientHandler.php b/src/ClientHandler.php
index 9fe921b..c98cbc6 100644
--- a/src/ClientHandler.php
+++ b/src/ClientHandler.php
@@ -41,12 +41,12 @@ class ClientHandler
     {
         $id = $this->idGenerator->generate();
         return $this->protocolWriter->write(
-            new Protocol\Message(
+            new Message(
                 new AdvancedJsonRpc\Request($id, $method, (object)$params)
             )
         )->then(function () use ($id) {
             $promise = new Promise;
-            $listener = function (Protocol\Message $msg) use ($id, $promise, &$listener) {
+            $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);
@@ -72,7 +72,7 @@ class ClientHandler
     public function notify(string $method, $params): Promise
     {
         return $this->protocolWriter->write(
-            new Protocol\Message(
+            new Message(
                 new AdvancedJsonRpc\Notification($method, (object)$params)
             )
         );
diff --git a/src/CompletionProvider.php b/src/CompletionProvider.php
index d8fefa8..e7dfcf1 100644
--- a/src/CompletionProvider.php
+++ b/src/CompletionProvider.php
@@ -4,7 +4,8 @@ declare(strict_types = 1);
 namespace LanguageServer;
 
 use LanguageServer\Index\ReadableIndex;
-use LanguageServer\Protocol\{
+use LanguageServer\Factory\CompletionItemFactory;
+use LanguageServerProtocol\{
     TextEdit,
     Range,
     Position,
@@ -16,7 +17,15 @@ use LanguageServer\Protocol\{
 };
 use Microsoft\PhpParser;
 use Microsoft\PhpParser\Node;
+use Microsoft\PhpParser\ResolvedName;
 use Generator;
+use function LanguageServer\FqnUtilities\{
+    nameConcat,
+    nameGetFirstPart,
+    nameGetParent,
+    nameStartsWith,
+    nameWithoutFirstPart
+};
 
 class CompletionProvider
 {
@@ -143,8 +152,11 @@ class CompletionProvider
      * @param CompletionContext $context The completion context
      * @return CompletionList
      */
-    public function provideCompletion(PhpDocument $doc, Position $pos, CompletionContext $context = null): CompletionList
-    {
+    public function provideCompletion(
+        PhpDocument $doc,
+        Position $pos,
+        CompletionContext $context = null
+    ): CompletionList {
         // This can be made much more performant if the tree follows specific invariants.
         $node = $doc->getNodeAtPosition($pos);
 
@@ -236,17 +248,15 @@ class CompletionProvider
                 $this->definitionResolver->resolveExpressionNodeToType($node->dereferencableExpression)
             );
 
-            // Add the object access operator to only get members of all parents
-            $prefixes = [];
-            foreach ($this->expandParentFqns($fqns) as $prefix) {
-                $prefixes[] = $prefix . '->';
-            }
-
-            // Collect all definitions that match any of the prefixes
-            foreach ($this->index->getDefinitions() as $fqn => $def) {
-                foreach ($prefixes as $prefix) {
-                    if (substr($fqn, 0, strlen($prefix)) === $prefix && $def->isMember) {
-                        $list->items[] = CompletionItem::fromDefinition($def);
+            // The FQNs of the symbol and its parents (eg the implemented interfaces)
+            foreach ($this->expandParentFqns($fqns) as $parentFqn) {
+                // Add the object access operator to only get members of all parents
+                $prefix = $parentFqn . '->';
+                $prefixLen = strlen($prefix);
+                // Collect fqn definitions
+                foreach ($this->index->getChildDefinitionsForFqn($parentFqn) as $fqn => $def) {
+                    if (substr($fqn, 0, $prefixLen) === $prefix && $def->isMember) {
+                        $list->items[] = CompletionItemFactory::fromDefinition($def);
                     }
                 }
             }
@@ -269,17 +279,15 @@ class CompletionProvider
                 $classType = $this->definitionResolver->resolveExpressionNodeToType($scoped->scopeResolutionQualifier)
             );
 
-            // Append :: operator to only get static members of all parents
-            $prefixes = [];
-            foreach ($this->expandParentFqns($fqns) as $prefix) {
-                $prefixes[] = $prefix . '::';
-            }
-
-            // Collect all definitions that match any of the prefixes
-            foreach ($this->index->getDefinitions() as $fqn => $def) {
-                foreach ($prefixes as $prefix) {
-                    if (substr(strtolower($fqn), 0, strlen($prefix)) === strtolower($prefix) && $def->isMember) {
-                        $list->items[] = CompletionItem::fromDefinition($def);
+            // The FQNs of the symbol and its parents (eg the implemented interfaces)
+            foreach ($this->expandParentFqns($fqns) as $parentFqn) {
+                // Append :: operator to only get static members of all parents
+                $prefix = strtolower($parentFqn . '::');
+                $prefixLen = strlen($prefix);
+                // Collect fqn definitions
+                foreach ($this->index->getChildDefinitionsForFqn($parentFqn) as $fqn => $def) {
+                    if (substr(strtolower($fqn), 0, $prefixLen) === $prefix && $def->isMember) {
+                        $list->items[] = CompletionItemFactory::fromDefinition($def);
                     }
                 }
             }
@@ -296,114 +304,278 @@ class CompletionProvider
             //    my_func|
             //    MY_CONS|
             //    MyCla|
+            //    \MyCla|
 
             // The name Node under the cursor
             $nameNode = isset($creation) ? $creation->classTypeDesignator : $node;
 
-            /** The typed name */
-            $prefix = $nameNode instanceof Node\QualifiedName
-                ? (string)PhpParser\ResolvedName::buildName($nameNode->nameParts, $nameNode->getFileContents())
-                : $nameNode->getText($node->getFileContents());
-            $prefixLen = strlen($prefix);
+            if ($nameNode instanceof Node\QualifiedName) {
+                /** @var string The typed name. */
+                $prefix = (string)PhpParser\ResolvedName::buildName($nameNode->nameParts, $nameNode->getFileContents());
+            } else {
+                $prefix = $nameNode->getText($node->getFileContents());
+            }
 
-            /** Whether the prefix is qualified (contains at least one backslash) */
-            $isQualified = $nameNode instanceof Node\QualifiedName && $nameNode->isQualifiedName();
-
-            /** Whether the prefix is fully qualified (begins with a backslash) */
-            $isFullyQualified = $nameNode instanceof Node\QualifiedName && $nameNode->isFullyQualifiedName();
-
-            /** The closest NamespaceDefinition Node */
             $namespaceNode = $node->getNamespaceDefinition();
+            /** @var string The current namespace without a leading backslash. */
+            $currentNamespace = $namespaceNode === null ? '' : $namespaceNode->name->getText();
 
-            /** @var string The name of the namespace */
-            $namespacedPrefix = null;
-            if ($namespaceNode) {
-                $namespacedPrefix = (string)PhpParser\ResolvedName::buildName($namespaceNode->name->nameParts, $node->getFileContents()) . '\\' . $prefix;
-                $namespacedPrefixLen = strlen($namespacedPrefix);
+            /** @var bool Whether the prefix is qualified (contains at least one backslash) */
+            $isFullyQualified = false;
+
+            /** @var bool Whether the prefix is qualified (contains at least one backslash) */
+            $isQualified = false;
+
+            if ($nameNode instanceof Node\QualifiedName) {
+                $isFullyQualified = $nameNode->isFullyQualifiedName();
+                $isQualified = $nameNode->isQualifiedName();
             }
 
-            // Get the namespace use statements
-            // TODO: use function statements, use const statements
+            /** @var bool Whether we are in a new expression */
+            $isCreation = isset($creation);
 
-            /** @var string[] $aliases A map from local alias to fully qualified name */
-            list($aliases,,) = $node->getImportTablesForCurrentScope();
+            /** @var array Import (use) tables */
+            $importTables = $node->getImportTablesForCurrentScope();
 
-            foreach ($aliases as $alias => $name) {
-                $aliases[$alias] = (string)$name;
+            if ($isFullyQualified) {
+                // \Prefix\Goes\Here| - Only return completions from the root namespace.
+                /** @var $items \Generator|CompletionItem[] Generator yielding CompletionItems indexed by their FQN */
+                $items = $this->getCompletionsForFqnPrefix($prefix, $isCreation, false);
+            } else if ($isQualified) {
+                // Prefix\Goes\Here|
+                $items = $this->getPartiallyQualifiedCompletions(
+                    $prefix,
+                    $currentNamespace,
+                    $importTables,
+                    $isCreation
+                );
+            } else {
+                // PrefixGoesHere|
+                $items = $this->getUnqualifiedCompletions($prefix, $currentNamespace, $importTables, $isCreation);
             }
 
-            // If there is a prefix that does not start with a slash, suggest `use`d symbols
-            if ($prefix && !$isFullyQualified) {
-                foreach ($aliases as $alias => $fqn) {
-                    // Suggest symbols that have been `use`d and match the prefix
-                    if (substr($alias, 0, $prefixLen) === $prefix && ($def = $this->index->getDefinition($fqn))) {
-                        $list->items[] = CompletionItem::fromDefinition($def);
-                    }
+            $list->items = array_values(iterator_to_array($items));
+            foreach ($list->items as $item) {
+                // Remove ()
+                if (is_string($item->insertText) && substr($item->insertText, strlen($item->insertText) - 2) === '()') {
+                    $item->insertText = substr($item->insertText, 0, -2);
                 }
             }
 
-            // Suggest global symbols that either
-            //  - start with the current namespace + prefix, if the Name node is not fully qualified
-            //  - start with just the prefix, if the Name node is fully qualified
-            foreach ($this->index->getDefinitions() as $fqn => $def) {
+        }
+        return $list;
+    }
 
-                $fqnStartsWithPrefix = substr($fqn, 0, $prefixLen) === $prefix;
-
-                if (
-                    // Exclude methods, properties etc.
-                    !$def->isMember
-                    && (
-                        !$prefix
-                        || (
-                            // Either not qualified, but a matching prefix with global fallback
-                            ($def->roamed && !$isQualified && $fqnStartsWithPrefix)
-                            // Or not in a namespace or a fully qualified name or AND matching the prefix
-                            || ((!$namespaceNode || $isFullyQualified) && $fqnStartsWithPrefix)
-                            // Or in a namespace, not fully qualified and matching the prefix + current namespace
-                            || (
-                                $namespaceNode
-                                && !$isFullyQualified
-                                && substr($fqn, 0, $namespacedPrefixLen) === $namespacedPrefix
-                            )
-                        )
-                    )
-                    // Only suggest classes for `new`
-                    && (!isset($creation) || $def->canBeInstantiated)
-                ) {
-                    $item = CompletionItem::fromDefinition($def);
-                    // Find the shortest name to reference the symbol
-                    if ($namespaceNode && ($alias = array_search($fqn, $aliases, true)) !== false) {
-                        // $alias is the name under which this definition is aliased in the current namespace
-                        $item->insertText = $alias;
-                    } else if ($namespaceNode && !($prefix && $isFullyQualified)) {
-                        // Insert the global FQN with leading backslash
-                        $item->insertText = '\\' . $fqn;
-                    } else {
-                        // Insert the FQN without leading backlash
-                        $item->insertText = $fqn;
-                    }
-                    // Don't insert the parenthesis for functions
-                    // TODO return a snippet and put the cursor inside
-                    if (substr($item->insertText, -2) === '()') {
-                        $item->insertText = substr($item->insertText, 0, -2);
-                    }
-                    $list->items[] = $item;
-                }
-            }
-
-            // If not a class instantiation, also suggest keywords
-            if (!isset($creation)) {
-                foreach (self::KEYWORDS as $keyword) {
-                    if (substr($keyword, 0, $prefixLen) === $prefix) {
-                        $item = new CompletionItem($keyword, CompletionItemKind::KEYWORD);
-                        $item->insertText = $keyword;
-                        $list->items[] = $item;
-                    }
-                }
+    private function getPartiallyQualifiedCompletions(
+        string $prefix,
+        string $currentNamespace,
+        array $importTables,
+        bool $requireCanBeInstantiated
+    ): \Generator {
+        // If the first part of the partially qualified name matches a namespace alias,
+        // only definitions below that  alias can be completed.
+        list($namespaceAliases,,) = $importTables;
+        $prefixFirstPart = nameGetFirstPart($prefix);
+        $foundAlias = $foundAliasFqn = null;
+        foreach ($namespaceAliases as $alias => $aliasFqn) {
+            if (strcasecmp($prefixFirstPart, $alias) === 0) {
+                $foundAlias = $alias;
+                $foundAliasFqn = (string)$aliasFqn;
+                break;
             }
         }
 
-        return $list;
+        if ($foundAlias !== null) {
+            yield from $this->getCompletionsFromAliasedNamespace(
+                $prefix,
+                $foundAlias,
+                $foundAliasFqn,
+                $requireCanBeInstantiated
+            );
+        } else {
+            yield from $this->getCompletionsForFqnPrefix(
+                nameConcat($currentNamespace, $prefix),
+                $requireCanBeInstantiated,
+                false
+            );
+        }
+    }
+
+    /**
+     * Yields completions for non-qualified global names.
+     *
+     * Yields
+     *  - Aliased classes
+     *  - Completions from current namespace
+     *  - Roamed completions from the global namespace (when not creating and not already in root NS)
+     *  - PHP keywords (when not creating)
+     *
+     * @return \Generator|CompletionItem[]
+     *   Yields CompletionItems
+     */
+    private function getUnqualifiedCompletions(
+        string $prefix,
+        string $currentNamespace,
+        array $importTables,
+        bool $requireCanBeInstantiated
+    ): \Generator {
+        // Aliases
+        list($namespaceAliases,,) = $importTables;
+        // use Foo\Bar
+        yield from $this->getCompletionsForAliases(
+            $prefix,
+            $namespaceAliases,
+            $requireCanBeInstantiated
+        );
+
+        // Completions from the current namespace
+        yield from $this->getCompletionsForFqnPrefix(
+            nameConcat($currentNamespace, $prefix),
+            $requireCanBeInstantiated,
+            false
+        );
+
+        if ($currentNamespace !== '' && $prefix === '') {
+            // Get additional suggestions from the global namespace.
+            // When completing e.g. for new |, suggest \DateTime
+            yield from $this->getCompletionsForFqnPrefix('', $requireCanBeInstantiated, true);
+        }
+
+        if (!$requireCanBeInstantiated) {
+            if ($currentNamespace !== '' && $prefix !== '') {
+                // Roamed definitions (i.e. global constants and functions). The prefix is checked against '', since
+                // in that case global completions have already been provided (including non-roamed definitions.)
+                yield from $this->getRoamedCompletions($prefix);
+            }
+
+            // Lastly and least importantly, suggest keywords.
+            yield from $this->getCompletionsForKeywords($prefix);
+        }
+    }
+
+    /**
+     * Gets completions for prefixes of fully qualified names in their parent namespace.
+     *
+     * @param string $prefix Prefix to complete for. Fully qualified.
+     * @param bool $requireCanBeInstantiated If set, only return classes.
+     * @param bool $insertFullyQualified If set, return completion with the leading \ inserted.
+     * @return \Generator|CompletionItem[]
+     *   Yields CompletionItems.
+     */
+    private function getCompletionsForFqnPrefix(
+        string $prefix,
+        bool $requireCanBeInstantiated,
+        bool $insertFullyQualified
+    ): \Generator {
+        $namespace = nameGetParent($prefix);
+        foreach ($this->index->getChildDefinitionsForFqn($namespace) as $fqn => $def) {
+            if ($requireCanBeInstantiated && !$def->canBeInstantiated) {
+                continue;
+            }
+            if (!nameStartsWith($fqn, $prefix)) {
+                continue;
+            }
+            $completion = CompletionItemFactory::fromDefinition($def);
+            if ($insertFullyQualified) {
+                $completion->insertText =  '\\' . $fqn;
+            }
+            yield $fqn => $completion;
+        }
+    }
+
+    /**
+     * Gets completions for non-qualified names matching the start of an used class, function, or constant.
+     *
+     * @param string $prefix Non-qualified name being completed for
+     * @param QualifiedName[] $aliases Array of alias FQNs indexed by the alias.
+     * @return \Generator|CompletionItem[]
+     *   Yields CompletionItems.
+     */
+    private function getCompletionsForAliases(
+        string $prefix,
+        array $aliases,
+        bool $requireCanBeInstantiated
+    ): \Generator {
+        foreach ($aliases as $alias => $aliasFqn) {
+            if (!nameStartsWith($alias, $prefix)) {
+                continue;
+            }
+            $definition = $this->index->getDefinition((string)$aliasFqn);
+            if ($definition) {
+                if ($requireCanBeInstantiated && !$definition->canBeInstantiated) {
+                    continue;
+                }
+                $completionItem = CompletionItemFactory::fromDefinition($definition);
+                $completionItem->insertText = $alias;
+                yield (string)$aliasFqn => $completionItem;
+            }
+        }
+    }
+
+    /**
+     * Gets completions for partially qualified names, where the first part is matched by an alias.
+     *
+     * @return \Generator|CompletionItem[]
+     *   Yields CompletionItems.
+     */
+    private function getCompletionsFromAliasedNamespace(
+        string $prefix,
+        string $alias,
+        string $aliasFqn,
+        bool $requireCanBeInstantiated
+    ): \Generator {
+        $prefixFirstPart = nameGetFirstPart($prefix);
+        // Matched alias.
+        $resolvedPrefix = nameConcat($aliasFqn, nameWithoutFirstPart($prefix));
+        $completionItems = $this->getCompletionsForFqnPrefix(
+            $resolvedPrefix,
+            $requireCanBeInstantiated,
+            false
+        );
+        // Convert FQNs in the CompletionItems so they are expressed in terms of the alias.
+        foreach ($completionItems as $fqn => $completionItem) {
+            /** @var string $fqn with the leading parts determined by the alias removed. Has the leading backslash. */
+            $nameWithoutAliasedPart = substr($fqn, strlen($aliasFqn));
+            $completionItem->insertText = $alias . $nameWithoutAliasedPart;
+            yield $fqn => $completionItem;
+        }
+    }
+
+    /**
+     * Gets completions for globally defined functions and constants (i.e. symbols which may be used anywhere)
+     *
+     * @return \Generator|CompletionItem[]
+     *   Yields CompletionItems.
+     */
+    private function getRoamedCompletions(string $prefix): \Generator
+    {
+        foreach ($this->index->getChildDefinitionsForFqn('') as $fqn => $def) {
+            if (!$def->roamed || !nameStartsWith($fqn, $prefix)) {
+                continue;
+            }
+            $completionItem = CompletionItemFactory::fromDefinition($def);
+            // Second-guessing the user here - do not trust roaming to work. If the same symbol is
+            // inserted in the current namespace, the code will stop working.
+            $completionItem->insertText =  '\\' . $fqn;
+            yield $fqn => $completionItem;
+        }
+    }
+
+    /**
+     * Completes PHP keywords.
+     *
+     * @return \Generator|CompletionItem[]
+     *   Yields CompletionItems.
+     */
+    private function getCompletionsForKeywords(string $prefix): \Generator
+    {
+        foreach (self::KEYWORDS as $keyword) {
+            if (nameStartsWith($keyword, $prefix)) {
+                $item = new CompletionItem($keyword, CompletionItemKind::KEYWORD);
+                $item->insertText = $keyword;
+                yield $keyword => $item;
+            }
+        }
     }
 
     /**
@@ -472,8 +644,9 @@ class CompletionProvider
                 }
             }
 
-            if ($level instanceof Node\Expression\AnonymousFunctionCreationExpression && $level->anonymousFunctionUseClause !== null &&
-                $level->anonymousFunctionUseClause->useVariableNameList !== null) {
+            if ($level instanceof Node\Expression\AnonymousFunctionCreationExpression
+                && $level->anonymousFunctionUseClause !== null
+                && $level->anonymousFunctionUseClause->useVariableNameList !== null) {
                 foreach ($level->anonymousFunctionUseClause->useVariableNameList->getValues() as $use) {
                     $useName = $use->getName();
                     if (empty($namePrefix) || strpos($useName, $namePrefix) !== false) {
diff --git a/src/ContentRetriever/ClientContentRetriever.php b/src/ContentRetriever/ClientContentRetriever.php
index b88042c..d83aad1 100644
--- a/src/ContentRetriever/ClientContentRetriever.php
+++ b/src/ContentRetriever/ClientContentRetriever.php
@@ -4,7 +4,7 @@ declare(strict_types = 1);
 namespace LanguageServer\ContentRetriever;
 
 use LanguageServer\LanguageClient;
-use LanguageServer\Protocol\{TextDocumentIdentifier, TextDocumentItem};
+use LanguageServerProtocol\{TextDocumentIdentifier, TextDocumentItem};
 use Sabre\Event\Promise;
 
 /**
diff --git a/src/Definition.php b/src/Definition.php
index 2c92eb9..d81594d 100644
--- a/src/Definition.php
+++ b/src/Definition.php
@@ -5,7 +5,7 @@ namespace LanguageServer;
 
 use LanguageServer\Index\ReadableIndex;
 use phpDocumentor\Reflection\{Types, Type, TypeResolver};
-use LanguageServer\Protocol\SymbolInformation;
+use LanguageServerProtocol\SymbolInformation;
 use Generator;
 
 /**
diff --git a/src/DefinitionResolver.php b/src/DefinitionResolver.php
index 990c196..adddf77 100644
--- a/src/DefinitionResolver.php
+++ b/src/DefinitionResolver.php
@@ -4,7 +4,8 @@ declare(strict_types = 1);
 namespace LanguageServer;
 
 use LanguageServer\Index\ReadableIndex;
-use LanguageServer\Protocol\SymbolInformation;
+use LanguageServer\Factory\SymbolInformationFactory;
+use LanguageServerProtocol\SymbolInformation;
 use Microsoft\PhpParser;
 use Microsoft\PhpParser\Node;
 use Microsoft\PhpParser\FunctionLike;
@@ -36,7 +37,7 @@ class DefinitionResolver
     private $docBlockFactory;
 
     /**
-     * Creates SignatureInformation
+     * Creates SignatureInformation instances
      *
      * @var SignatureInformationFactory
      */
@@ -233,7 +234,7 @@ class DefinitionResolver
             }
         }
 
-        $def->symbolInformation = SymbolInformation::fromNode($node, $fqn);
+        $def->symbolInformation = SymbolInformationFactory::fromNode($node, $fqn);
 
         if ($def->symbolInformation !== null) {
             $def->type = $this->getTypeFromNode($node);
@@ -437,6 +438,7 @@ class DefinitionResolver
 
         // Find the right class that implements the member
         $implementorFqns = [$classFqn];
+        $visitedFqns = [];
 
         while ($implementorFqn = array_shift($implementorFqns)) {
             // If the member FQN exists, return it
@@ -449,10 +451,15 @@ class DefinitionResolver
             if ($implementorDef === null) {
                 break;
             }
+            // Note the FQN as visited
+            $visitedFqns[] = $implementorFqn;
             // Repeat for parent class
             if ($implementorDef->extends) {
                 foreach ($implementorDef->extends as $extends) {
-                    $implementorFqns[] = $extends;
+                    // Don't add the parent FQN if it's already been visited
+                    if (!\in_array($extends, $visitedFqns)) {
+                        $implementorFqns[] = $extends;
+                    }
                 }
             }
         }
@@ -1232,7 +1239,13 @@ class DefinitionResolver
         if (
             $node instanceof PhpParser\ClassLike
         ) {
-            return (string) $node->getNamespacedName();
+            $className = (string)$node->getNamespacedName();
+            // An (invalid) class declaration without a name will have an empty string as name,
+            // but should not define an FQN
+            if ($className === '') {
+                return null;
+            }
+            return $className;
         }
 
         // INPUT                   OUTPUT:
diff --git a/src/Factory/CompletionItemFactory.php b/src/Factory/CompletionItemFactory.php
new file mode 100644
index 0000000..ce00fa6
--- /dev/null
+++ b/src/Factory/CompletionItemFactory.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace LanguageServer\Factory;
+
+use LanguageServer\Definition;
+use LanguageServerProtocol\CompletionItem;
+use LanguageServerProtocol\CompletionItemKind;
+use LanguageServerProtocol\SymbolKind;
+
+class CompletionItemFactory
+{
+    /**
+     * Creates a CompletionItem for a Definition
+     *
+     * @param Definition $def
+     * @return CompletionItem|null
+     */
+    public static function fromDefinition(Definition $def)
+    {
+        $item = new CompletionItem;
+        $item->label = $def->symbolInformation->name;
+        $item->kind = CompletionItemKind::fromSymbolKind($def->symbolInformation->kind);
+        if ($def->type) {
+            $item->detail = (string)$def->type;
+        } else if ($def->symbolInformation->containerName) {
+            $item->detail = $def->symbolInformation->containerName;
+        }
+        if ($def->documentation) {
+            $item->documentation = $def->documentation;
+        }
+        if ($def->isStatic && $def->symbolInformation->kind === SymbolKind::PROPERTY) {
+            $item->insertText = '$' . $def->symbolInformation->name;
+        }
+        return $item;
+    }
+}
diff --git a/src/Factory/LocationFactory.php b/src/Factory/LocationFactory.php
new file mode 100644
index 0000000..3ccc80b
--- /dev/null
+++ b/src/Factory/LocationFactory.php
@@ -0,0 +1,32 @@
+<?php
+
+namespace LanguageServer\Factory;
+
+use LanguageServerProtocol\Location;
+use LanguageServerProtocol\Position;
+use LanguageServerProtocol\Range;
+use Microsoft\PhpParser\Node;
+use Microsoft\PhpParser\PositionUtilities;
+
+class LocationFactory
+{
+    /**
+     * Returns the location of the node
+     *
+     * @param Node $node
+     * @return self
+     */
+    public static function fromNode(Node $node): Location
+    {
+        $range = PositionUtilities::getRangeFromPosition(
+            $node->getStart(),
+            $node->getWidth(),
+            $node->getFileContents()
+        );
+
+        return new Location($node->getUri(), new Range(
+            new Position($range->start->line, $range->start->character),
+            new Position($range->end->line, $range->end->character)
+        ));
+    }
+}
diff --git a/src/Factory/RangeFactory.php b/src/Factory/RangeFactory.php
new file mode 100644
index 0000000..b438db5
--- /dev/null
+++ b/src/Factory/RangeFactory.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace LanguageServer\Factory;
+
+use LanguageServerProtocol\Position;
+use LanguageServerProtocol\Range;
+use Microsoft\PhpParser\Node;
+use Microsoft\PhpParser\PositionUtilities;
+
+class RangeFactory
+{
+    /**
+     * Returns the range the node spans
+     *
+     * @param Node $node
+     * @return self
+     */
+    public static function fromNode(Node $node)
+    {
+        $range = PositionUtilities::getRangeFromPosition(
+            $node->getStart(),
+            $node->getWidth(),
+            $node->getFileContents()
+        );
+
+        return new Range(
+            new Position($range->start->line, $range->start->character),
+            new Position($range->end->line, $range->end->character)
+        );
+    }
+}
diff --git a/src/Protocol/SymbolInformation.php b/src/Factory/SymbolInformationFactory.php
similarity index 74%
rename from src/Protocol/SymbolInformation.php
rename to src/Factory/SymbolInformationFactory.php
index 499e417..b03d951 100644
--- a/src/Protocol/SymbolInformation.php
+++ b/src/Factory/SymbolInformationFactory.php
@@ -1,44 +1,16 @@
 <?php
 
-namespace LanguageServer\Protocol;
+namespace LanguageServer\Factory;
 
-use Microsoft\PhpParser;
+use LanguageServerProtocol\Location;
+use LanguageServerProtocol\SymbolInformation;
+use LanguageServerProtocol\SymbolKind;
 use Microsoft\PhpParser\Node;
+use Microsoft\PhpParser\ResolvedName;
+use LanguageServer\Factory\LocationFactory;
 
-/**
- * Represents information about programming constructs like variables, classes,
- * interfaces etc.
- */
-class SymbolInformation
+class SymbolInformationFactory
 {
-    /**
-     * The name of this symbol.
-     *
-     * @var string
-     */
-    public $name;
-
-    /**
-     * The kind of this symbol.
-     *
-     * @var int
-     */
-    public $kind;
-
-    /**
-     * The location of this symbol.
-     *
-     * @var Location
-     */
-    public $location;
-
-    /**
-     * The name of the symbol containing this symbol.
-     *
-     * @var string|null
-     */
-    public $containerName;
-
     /**
      * Converts a Node to a SymbolInformation
      *
@@ -48,7 +20,7 @@ class SymbolInformation
      */
     public static function fromNode($node, string $fqn = null)
     {
-        $symbol = new self;
+        $symbol = new SymbolInformation();
         if ($node instanceof Node\Statement\ClassDeclaration) {
             $symbol->kind = SymbolKind::CLASS_;
         } else if ($node instanceof Node\Statement\TraitDeclaration) {
@@ -98,7 +70,7 @@ class SymbolInformation
             $symbol->name = $node->getName();
         } else if (isset($node->name)) {
             if ($node->name instanceof Node\QualifiedName) {
-                $symbol->name = (string)PhpParser\ResolvedName::buildName($node->name->nameParts, $node->getFileContents());
+                $symbol->name = (string)ResolvedName::buildName($node->name->nameParts, $node->getFileContents());
             } else {
                 $symbol->name = ltrim((string)$node->name->getText($node->getFileContents()), "$");
             }
@@ -108,7 +80,7 @@ class SymbolInformation
             return null;
         }
 
-        $symbol->location = Location::fromNode($node);
+        $symbol->location = LocationFactory::fromNode($node);
         if ($fqn !== null) {
             $parts = preg_split('/(::|->|\\\\)/', $fqn);
             array_pop($parts);
@@ -116,18 +88,4 @@ class SymbolInformation
         }
         return $symbol;
     }
-
-    /**
-     * @param string $name
-     * @param int $kind
-     * @param Location $location
-     * @param string $containerName
-     */
-    public function __construct($name = null, $kind = null, $location = null, $containerName = null)
-    {
-        $this->name = $name;
-        $this->kind = $kind;
-        $this->location = $location;
-        $this->containerName = $containerName;
-    }
 }
diff --git a/src/FqnUtilities.php b/src/FqnUtilities.php
index fcd6027..57e3776 100644
--- a/src/FqnUtilities.php
+++ b/src/FqnUtilities.php
@@ -28,3 +28,91 @@ function getFqnsFromType($type): array
     }
     return $fqns;
 }
+
+/**
+ * Returns parent of an FQN.
+ *
+ * getFqnParent('') === ''
+ * getFqnParent('\\') === ''
+ * getFqnParent('\A') === ''
+ * getFqnParent('A') === ''
+ * getFqnParent('\A\') === '\A' // Empty trailing name is considered a name.
+ *
+ * @return string
+ */
+function nameGetParent(string $name): string
+{
+    if ($name === '') { // Special-case handling for the root namespace.
+        return '';
+    }
+    $parts = explode('\\', $name);
+    array_pop($parts);
+    return implode('\\', $parts);
+}
+
+/**
+ * Concatenates two names.
+ *
+ * nameConcat('\Foo\Bar', 'Baz') === '\Foo\Bar\Baz'
+ * nameConcat('\Foo\Bar\\', '\Baz') === '\Foo\Bar\Baz'
+ * nameConcat('\\', 'Baz') === '\Baz'
+ * nameConcat('', 'Baz') === 'Baz'
+ *
+ * @return string
+ */
+function nameConcat(string $a, string $b): string
+{
+    if ($a === '') {
+        return $b;
+    }
+    $a = rtrim($a, '\\');
+    $b = ltrim($b, '\\');
+    return "$a\\$b";
+}
+
+/**
+ * Returns the first component of $name.
+ *
+ * nameGetFirstPart('Foo\Bar') === 'Foo'
+ * nameGetFirstPart('\Foo\Bar') === 'Foo'
+ * nameGetFirstPart('') === ''
+ * nameGetFirstPart('\') === ''
+ */
+function nameGetFirstPart(string $name): string
+{
+    $parts = explode('\\', $name, 3);
+    if ($parts[0] === '' && count($parts) > 1) {
+        return $parts[1];
+    } else {
+        return $parts[0];
+    }
+}
+
+/**
+ * Removes the first component of $name.
+ *
+ * nameWithoutFirstPart('Foo\Bar') === 'Bar'
+ * nameWithoutFirstPart('\Foo\Bar') === 'Bar'
+ * nameWithoutFirstPart('') === ''
+ * nameWithoutFirstPart('\') === ''
+ */
+function nameWithoutFirstPart(string $name): string
+{
+    $parts = explode('\\', $name, 3);
+    if ($parts[0] === '') {
+        array_shift($parts);
+    }
+    array_shift($parts);
+    return implode('\\', $parts);
+}
+
+/**
+ * @param string $name Name to match against
+ * @param string $prefix Prefix $name has to starts with
+ * @return bool
+ */
+function nameStartsWith(string $name, string $prefix): bool
+{
+    return strlen($name) >= strlen($prefix)
+        && strncmp($name, $prefix, strlen($prefix)) === 0;
+}
diff --git a/src/Index/AbstractAggregateIndex.php b/src/Index/AbstractAggregateIndex.php
index 5377c3a..8c8c95a 100644
--- a/src/Index/AbstractAggregateIndex.php
+++ b/src/Index/AbstractAggregateIndex.php
@@ -99,20 +99,29 @@ abstract class AbstractAggregateIndex implements ReadableIndex
     }
 
     /**
-     * Returns an associative array [string => Definition] that maps fully qualified symbol names
-     * to Definitions
+     * Returns a Generator providing an associative array [string => Definition]
+     * that maps fully qualified symbol names to Definitions (global or not)
      *
-     * @return Definition[]
+     * @return \Generator yields Definition
      */
-    public function getDefinitions(): array
+    public function getDefinitions(): \Generator
     {
-        $defs = [];
         foreach ($this->getIndexes() as $index) {
-            foreach ($index->getDefinitions() as $fqn => $def) {
-                $defs[$fqn] = $def;
-            }
+            yield from $index->getDefinitions();
+        }
+    }
+
+    /**
+     * Returns a Generator that yields all the direct child Definitions of a given FQN
+     *
+     * @param string $fqn
+     * @return \Generator yields Definition
+     */
+    public function getChildDefinitionsForFqn(string $fqn): \Generator
+    {
+        foreach ($this->getIndexes() as $index) {
+            yield from $index->getChildDefinitionsForFqn($fqn);
         }
-        return $defs;
     }
 
     /**
@@ -132,19 +141,15 @@ abstract class AbstractAggregateIndex implements ReadableIndex
     }
 
     /**
-     * Returns all URIs in this index that reference a symbol
+     * Returns a Generator providing all URIs in this index that reference a symbol
      *
      * @param string $fqn The fully qualified name of the symbol
-     * @return string[]
+     * @return \Generator yields string
      */
-    public function getReferenceUris(string $fqn): array
+    public function getReferenceUris(string $fqn): \Generator
     {
-        $refs = [];
         foreach ($this->getIndexes() as $index) {
-            foreach ($index->getReferenceUris($fqn) as $ref) {
-                $refs[] = $ref;
-            }
+            yield from $index->getReferenceUris($fqn);
         }
-        return $refs;
     }
 }
diff --git a/src/Index/Index.php b/src/Index/Index.php
index 6f95a4b..0d61f9c 100644
--- a/src/Index/Index.php
+++ b/src/Index/Index.php
@@ -15,14 +15,26 @@ class Index implements ReadableIndex, \Serializable
     use EmitterTrait;
 
     /**
-     * An associative array that maps fully qualified symbol names to Definitions
+     * An associative array that maps splitted fully qualified symbol names
+     * to definitions, eg :
+     * [
+     *     'Psr' => [
+     *         '\Log' => [
+     *             '\LoggerInterface' => [
+     *                 ''        => $def1, // definition for 'Psr\Log\LoggerInterface' which is non-member
+     *                 '->log()' => $def2, // definition for 'Psr\Log\LoggerInterface->log()' which is a member
+     *             ],
+     *         ],
+     *     ],
+     * ]
      *
-     * @var Definition[]
+     * @var array
      */
     private $definitions = [];
 
     /**
-     * An associative array that maps fully qualified symbol names to arrays of document URIs that reference the symbol
+     * An associative array that maps fully qualified symbol names
+     * to arrays of document URIs that reference the symbol
      *
      * @var string[][]
      */
@@ -84,14 +96,46 @@ class Index implements ReadableIndex, \Serializable
     }
 
     /**
-     * Returns an associative array [string => Definition] that maps fully qualified symbol names
-     * to Definitions
+     * Returns a Generator providing an associative array [string => Definition]
+     * that maps fully qualified symbol names to Definitions (global or not)
      *
-     * @return Definition[]
+     * @return \Generator yields Definition
      */
-    public function getDefinitions(): array
+    public function getDefinitions(): \Generator
     {
-        return $this->definitions;
+        yield from $this->yieldDefinitionsRecursively($this->definitions);
+    }
+
+    /**
+     * Returns a Generator that yields all the direct child Definitions of a given FQN
+     *
+     * @param string $fqn
+     * @return \Generator yields Definition
+     */
+    public function getChildDefinitionsForFqn(string $fqn): \Generator
+    {
+        $parts = $this->splitFqn($fqn);
+        if ('' === end($parts)) {
+            // we want to return all the definitions in the given FQN, not only
+            // the one (non member) matching exactly the FQN.
+            array_pop($parts);
+        }
+
+        $result = $this->getIndexValue($parts, $this->definitions);
+        if (!$result) {
+            return;
+        }
+        foreach ($result as $name => $item) {
+            // Don't yield the parent
+            if ($name === '') {
+                continue;
+            }
+            if ($item instanceof Definition) {
+                yield $fqn.$name => $item;
+            } elseif (is_array($item) && isset($item[''])) {
+                yield $fqn.$name => $item[''];
+            }
+        }
     }
 
     /**
@@ -103,12 +147,17 @@ class Index implements ReadableIndex, \Serializable
      */
     public function getDefinition(string $fqn, bool $globalFallback = false)
     {
-        if (isset($this->definitions[$fqn])) {
-            return $this->definitions[$fqn];
+        $parts = $this->splitFqn($fqn);
+        $result = $this->getIndexValue($parts, $this->definitions);
+
+        if ($result instanceof Definition) {
+            return $result;
         }
+
         if ($globalFallback) {
             $parts = explode('\\', $fqn);
             $fqn = end($parts);
+
             return $this->getDefinition($fqn);
         }
     }
@@ -122,7 +171,9 @@ class Index implements ReadableIndex, \Serializable
      */
     public function setDefinition(string $fqn, Definition $definition)
     {
-        $this->definitions[$fqn] = $definition;
+        $parts = $this->splitFqn($fqn);
+        $this->indexDefinition(0, $parts, $this->definitions, $definition);
+
         $this->emit('definition-added');
     }
 
@@ -135,19 +186,23 @@ class Index implements ReadableIndex, \Serializable
      */
     public function removeDefinition(string $fqn)
     {
-        unset($this->definitions[$fqn]);
+        $parts = $this->splitFqn($fqn);
+        $this->removeIndexedDefinition(0, $parts, $this->definitions, $this->definitions);
+
         unset($this->references[$fqn]);
     }
 
     /**
-     * Returns all URIs in this index that reference a symbol
+     * Returns a Generator providing all URIs in this index that reference a symbol
      *
      * @param string $fqn The fully qualified name of the symbol
-     * @return string[]
+     * @return \Generator yields string
      */
-    public function getReferenceUris(string $fqn): array
+    public function getReferenceUris(string $fqn): \Generator
     {
-        return $this->references[$fqn] ?? [];
+        foreach ($this->references[$fqn] ?? [] as $uri) {
+            yield $uri;
+        }
     }
 
     /**
@@ -204,6 +259,15 @@ class Index implements ReadableIndex, \Serializable
     public function unserialize($serialized)
     {
         $data = unserialize($serialized);
+
+        if (isset($data['definitions'])) {
+            foreach ($data['definitions'] as $fqn => $definition) {
+                $this->setDefinition($fqn, $definition);
+            }
+
+            unset($data['definitions']);
+        }
+
         foreach ($data as $prop => $val) {
             $this->$prop = $val;
         }
@@ -215,10 +279,164 @@ class Index implements ReadableIndex, \Serializable
     public function serialize()
     {
         return serialize([
-            'definitions' => $this->definitions,
+            'definitions' => iterator_to_array($this->getDefinitions()),
             'references' => $this->references,
             'complete' => $this->complete,
             'staticComplete' => $this->staticComplete
         ]);
     }
+
+    /**
+     * Returns a Generator that yields all the Definitions in the given $storage recursively.
+     * The generator yields key => value pairs, e.g.
+     * `'Psr\Log\LoggerInterface->log()' => $definition`
+     *
+     * @param array &$storage
+     * @param string $prefix (optional)
+     * @return \Generator
+     */
+    private function yieldDefinitionsRecursively(array &$storage, string $prefix = ''): \Generator
+    {
+        foreach ($storage as $key => $value) {
+            if (!is_array($value)) {
+                yield $prefix.$key => $value;
+            } else {
+                yield from $this->yieldDefinitionsRecursively($value, $prefix.$key);
+            }
+        }
+    }
+
+    /**
+     * Splits the given FQN into an array, eg :
+     * - `'Psr\Log\LoggerInterface->log'` will be `['Psr', '\Log', '\LoggerInterface', '->log()']`
+     * - `'\Exception->getMessage()'`     will be `['\Exception', '->getMessage()']`
+     * - `'PHP_VERSION'`                  will be `['PHP_VERSION']`
+     *
+     * @param string $fqn
+     * @return string[]
+     */
+    private function splitFqn(string $fqn): array
+    {
+        // split fqn at backslashes
+        $parts = explode('\\', $fqn);
+
+        // write back the backslash prefix to the first part if it was present
+        if ('' === $parts[0] && count($parts) > 1) {
+            $parts = array_slice($parts, 1);
+            $parts[0] = '\\' . $parts[0];
+        }
+
+        // write back the backslashes prefixes for the other parts
+        for ($i = 1; $i < count($parts); $i++) {
+            $parts[$i] = '\\' . $parts[$i];
+        }
+
+        // split the last part in 2 parts at the operator
+        $hasOperator = false;
+        $lastPart = end($parts);
+        foreach (['::', '->'] as $operator) {
+            $endParts = explode($operator, $lastPart);
+            if (count($endParts) > 1) {
+                $hasOperator = true;
+                // replace the last part by its pieces
+                array_pop($parts);
+                $parts[] = $endParts[0];
+                $parts[] = $operator . $endParts[1];
+                break;
+            }
+        }
+
+        // The end($parts) === '' holds for the root namespace.
+        if (!$hasOperator && end($parts) !== '') {
+            // add an empty part to store the non-member definition to avoid
+            // definition collisions in the index array, eg
+            // 'Psr\Log\LoggerInterface' will be stored at
+            // ['Psr']['\Log']['\LoggerInterface'][''] to be able to also store
+            // member definitions, ie 'Psr\Log\LoggerInterface->log()' will be
+            // stored at ['Psr']['\Log']['\LoggerInterface']['->log()']
+            $parts[] = '';
+        }
+
+        return $parts;
+    }
+
+    /**
+     * Return the values stored in this index under the given $parts array.
+     * It can be an index node or a Definition if the $parts are precise
+     * enough. Returns null when nothing is found.
+     *
+     * @param string[] $path              The splitted FQN
+     * @param array|Definition &$storage  The current level to look for $path.
+     * @return array|Definition|null
+     */
+    private function getIndexValue(array $path, &$storage)
+    {
+        // Empty path returns the object itself.
+        if (empty($path)) {
+            return $storage;
+        }
+
+        $part = array_shift($path);
+
+        if (!isset($storage[$part])) {
+            return null;
+        }
+
+        return $this->getIndexValue($path, $storage[$part]);
+    }
+
+    /**
+     * Recursive function that stores the given Definition in the given $storage array represented
+     * as a tree matching the given $parts.
+     *
+     * @param int $level              The current level of FQN part
+     * @param string[] $parts         The splitted FQN
+     * @param array &$storage         The array in which to store the $definition
+     * @param Definition $definition  The Definition to store
+     */
+    private function indexDefinition(int $level, array $parts, array &$storage, Definition $definition)
+    {
+        $part = $parts[$level];
+
+        if ($level + 1 === count($parts)) {
+            $storage[$part] = $definition;
+
+            return;
+        }
+
+        if (!isset($storage[$part])) {
+            $storage[$part] = [];
+        }
+
+        $this->indexDefinition($level + 1, $parts, $storage[$part], $definition);
+    }
+
+    /**
+     * Recursive function that removes the definition matching the given $parts from the given
+     * $storage array. The function also looks up recursively to remove the parents of the
+     * definition which no longer has children to avoid to let empty arrays in the index.
+     *
+     * @param int $level              The current level of FQN part
+     * @param string[] $parts         The splitted FQN
+     * @param array &$storage         The current array in which to remove data
+     * @param array &$rootStorage     The root storage array
+     */
+    private function removeIndexedDefinition(int $level, array $parts, array &$storage, array &$rootStorage)
+    {
+        $part = $parts[$level];
+
+        if ($level + 1 === count($parts)) {
+            if (isset($storage[$part])) {
+                unset($storage[$part]);
+
+                if (0 === count($storage)) {
+                    // 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);
+                }
+            }
+        } else {
+            $this->removeIndexedDefinition($level + 1, $parts, $storage[$part], $rootStorage);
+        }
+    }
 }
diff --git a/src/Index/ReadableIndex.php b/src/Index/ReadableIndex.php
index 67b20b6..505bb9a 100644
--- a/src/Index/ReadableIndex.php
+++ b/src/Index/ReadableIndex.php
@@ -30,12 +30,20 @@ interface ReadableIndex extends EmitterInterface
     public function isStaticComplete(): bool;
 
     /**
-     * Returns an associative array [string => Definition] that maps fully qualified symbol names
-     * to Definitions
+     * Returns a Generator providing an associative array [string => Definition]
+     * that maps fully qualified symbol names to Definitions (global or not)
      *
-     * @return Definitions[]
+     * @return \Generator yields Definition
      */
-    public function getDefinitions(): array;
+    public function getDefinitions(): \Generator;
+
+    /**
+     * Returns a Generator that yields all the direct child Definitions of a given FQN
+     *
+     * @param string $fqn
+     * @return \Generator yields Definition
+     */
+    public function getChildDefinitionsForFqn(string $fqn): \Generator;
 
     /**
      * Returns the Definition object by a specific FQN
@@ -47,10 +55,10 @@ interface ReadableIndex extends EmitterInterface
     public function getDefinition(string $fqn, bool $globalFallback = false);
 
     /**
-     * Returns all URIs in this index that reference a symbol
+     * Returns a Generator that yields all URIs in this index that reference a symbol
      *
      * @param string $fqn The fully qualified name of the symbol
-     * @return string[]
+     * @return \Generator yields string
      */
-    public function getReferenceUris(string $fqn): array;
+    public function getReferenceUris(string $fqn): \Generator;
 }
diff --git a/src/Indexer.php b/src/Indexer.php
index 85d1787..7ebff3f 100644
--- a/src/Indexer.php
+++ b/src/Indexer.php
@@ -6,7 +6,7 @@ namespace LanguageServer;
 use LanguageServer\Cache\Cache;
 use LanguageServer\FilesFinder\FilesFinder;
 use LanguageServer\Index\{DependenciesIndex, Index};
-use LanguageServer\Protocol\MessageType;
+use LanguageServerProtocol\MessageType;
 use Webmozart\PathUtil\Path;
 use Sabre\Event\Promise;
 use function Sabre\Event\coroutine;
@@ -16,7 +16,7 @@ class Indexer
     /**
      * @var int The prefix for every cache item
      */
-    const CACHE_VERSION = 2;
+    const CACHE_VERSION = 3;
 
     /**
      * @var FilesFinder
diff --git a/src/LanguageServer.php b/src/LanguageServer.php
index 46281f5..a30992b 100644
--- a/src/LanguageServer.php
+++ b/src/LanguageServer.php
@@ -3,15 +3,15 @@ declare(strict_types = 1);
 
 namespace LanguageServer;
 
-use LanguageServer\Protocol\{
+use LanguageServerProtocol\{
     ServerCapabilities,
     ClientCapabilities,
     TextDocumentSyncKind,
-    Message,
     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};
@@ -165,8 +165,11 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
      * @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.
      * @return Promise <InitializeResult>
      */
-    public function initialize(ClientCapabilities $capabilities, string $rootPath = null, int $processId = null): Promise
+    public function initialize(ClientCapabilities $capabilities, string $rootPath = null, int $processId = null, string $rootUri = null): Promise
     {
+        if ($rootPath === null) {
+            $rootPath = uriToPath($rootUri);
+        }
         return coroutine(function () use ($capabilities, $rootPath, $processId) {
 
             if ($capabilities->xfilesProvider) {
diff --git a/src/Protocol/Message.php b/src/Message.php
similarity index 96%
rename from src/Protocol/Message.php
rename to src/Message.php
index 8df5d0e..fb51110 100644
--- a/src/Protocol/Message.php
+++ b/src/Message.php
@@ -1,9 +1,10 @@
 <?php
 declare(strict_types = 1);
 
-namespace LanguageServer\Protocol;
+namespace LanguageServer;
 
 use AdvancedJsonRpc\Message as MessageBody;
+use LanguageServer\Message;
 
 class Message
 {
diff --git a/src/PhpDocument.php b/src/PhpDocument.php
index 373ba69..d148f9c 100644
--- a/src/PhpDocument.php
+++ b/src/PhpDocument.php
@@ -4,7 +4,7 @@ declare(strict_types = 1);
 namespace LanguageServer;
 
 use LanguageServer\Index\Index;
-use LanguageServer\Protocol\{
+use LanguageServerProtocol\{
     Diagnostic, Position, Range
 };
 use Microsoft\PhpParser;
diff --git a/src/Protocol/ClientCapabilities.php b/src/Protocol/ClientCapabilities.php
deleted file mode 100644
index 5228c7d..0000000
--- a/src/Protocol/ClientCapabilities.php
+++ /dev/null
@@ -1,27 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-class ClientCapabilities
-{
-    /**
-     * The client supports workspace/xfiles requests
-     *
-     * @var bool|null
-     */
-    public $xfilesProvider;
-
-    /**
-     * The client supports textDocument/xcontent requests
-     *
-     * @var bool|null
-     */
-    public $xcontentProvider;
-
-    /**
-     * The client supports xcache/* requests
-     *
-     * @var bool|null
-     */
-    public $xcacheProvider;
-}
diff --git a/src/Protocol/CodeActionContext.php b/src/Protocol/CodeActionContext.php
deleted file mode 100644
index 88e2e04..0000000
--- a/src/Protocol/CodeActionContext.php
+++ /dev/null
@@ -1,17 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Contains additional diagnostic information about the context in which
- * a code action is run.
- */
-class CodeActionContext
-{
-    /**
-     * An array of diagnostics.
-     *
-     * @var Diagnostic[]
-     */
-    public $diagnostics;
-}
diff --git a/src/Protocol/CodeLens.php b/src/Protocol/CodeLens.php
deleted file mode 100644
index 557cf9c..0000000
--- a/src/Protocol/CodeLens.php
+++ /dev/null
@@ -1,35 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * A code lens represents a command that should be shown along with
- * source text, like the number of references, a way to run tests, etc.
- *
- * A code lens is _unresolved_ when no command is associated to it. For performance
- * reasons the creation of a code lens and resolving should be done in two stages.
- */
-class CodeLens
-{
-    /**
-     * The range in which this code lens is valid. Should only span a single line.
-     *
-     * @var Range
-     */
-    public $range;
-
-    /**
-     * The command this code lens represents.
-     *
-     * @var Command|null
-     */
-    public $command;
-
-    /**
-     * A data entry field that is preserved on a code lens item between
-     * a code lens and a code lens resolve request.
-     *
-     * @var mixed|null
-     */
-    public $data;
-}
diff --git a/src/Protocol/CodeLensOptions.php b/src/Protocol/CodeLensOptions.php
deleted file mode 100644
index bd6548d..0000000
--- a/src/Protocol/CodeLensOptions.php
+++ /dev/null
@@ -1,16 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Code Lens options.
- */
-class CodeLensOptions
-{
-    /**
-     * Code lens has a resolve provider as well.
-     *
-     * @var bool|null
-     */
-    public $resolveProvider;
-}
diff --git a/src/Protocol/Command.php b/src/Protocol/Command.php
deleted file mode 100644
index 27d5a7e..0000000
--- a/src/Protocol/Command.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Represents a reference to a command. Provides a title which will be used to represent a command in the UI and,
- * optionally, an array of arguments which will be passed to the command handler function when invoked.
- */
-class Command
-{
-    /**
-     * Title of the command, like `save`.
-     *
-     * @var string
-     */
-    public $title;
-
-    /**
-     * The identifier of the actual command handler.
-     *
-     * @var string
-     */
-    public $command;
-
-    /**
-     * Arguments that the command handler should be
-     * invoked with.
-     *
-     * @var mixed[]|null
-     */
-    public $arguments;
-}
diff --git a/src/Protocol/CompletionContext.php b/src/Protocol/CompletionContext.php
deleted file mode 100644
index f538867..0000000
--- a/src/Protocol/CompletionContext.php
+++ /dev/null
@@ -1,30 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Contains additional information about the context in which a completion request is triggered.
- */
-class CompletionContext
-{
-    /**
-     * How the completion was triggered.
-     *
-     * @var int
-     */
-    public $triggerKind;
-
-    /**
-     * The trigger character (a single character) that has trigger code complete.
-     * Is null if `triggerKind !== CompletionTriggerKind::TRIGGER_CHARACTER`
-     *
-     * @var string|null
-     */
-    public $triggerCharacter;
-
-    public function __construct(int $triggerKind = null, string $triggerCharacter = null)
-    {
-        $this->triggerKind = $triggerKind;
-        $this->triggerCharacter = $triggerCharacter;
-    }
-}
diff --git a/src/Protocol/CompletionItem.php b/src/Protocol/CompletionItem.php
deleted file mode 100644
index 64bc69d..0000000
--- a/src/Protocol/CompletionItem.php
+++ /dev/null
@@ -1,164 +0,0 @@
-<?php
-declare(strict_types = 1);
-
-namespace LanguageServer\Protocol;
-
-use LanguageServer\Definition;
-
-class CompletionItem
-{
-    /**
-     * The label of this completion item. By default
-     * also the text that is inserted when selecting
-     * this completion.
-     *
-     * @var string
-     */
-    public $label;
-
-    /**
-     * The kind of this completion item. Based of the kind
-     * an icon is chosen by the editor.
-     *
-     * @var int|null
-     */
-    public $kind;
-
-    /**
-     * A human-readable string with additional information
-     * about this item, like type or symbol information.
-     *
-     * @var string|null
-     */
-    public $detail;
-
-    /**
-     * A human-readable string that represents a doc-comment.
-     *
-     * @var string|null
-     */
-    public $documentation;
-
-    /**
-     * A string that shoud be used when comparing this item
-     * with other items. When `falsy` the label is used.
-     *
-     * @var string|null
-     */
-    public $sortText;
-
-    /**
-     * A string that should be used when filtering a set of
-     * completion items. When `falsy` the label is used.
-     *
-     * @var string|null
-     */
-    public $filterText;
-
-    /**
-     * A string that should be inserted a document when selecting
-     * this completion. When `falsy` the label is used.
-     *
-     * @var string|null
-     */
-    public $insertText;
-
-    /**
-     * An edit which is applied to a document when selecting
-     * this completion. When an edit is provided the value of
-     * insertText is ignored.
-     *
-     * @var TextEdit|null
-     */
-    public $textEdit;
-
-    /**
-     * An optional array of additional text edits that are applied when
-     * selecting this completion. Edits must not overlap with the main edit
-     * nor with themselves.
-     *
-     * @var TextEdit[]|null
-     */
-    public $additionalTextEdits;
-
-    /**
-     * An optional command that is executed *after* inserting this completion. *Note* that
-     * additional modifications to the current document should be described with the
-     * additionalTextEdits-property.
-     *
-     * @var Command|null
-     */
-    public $command;
-
-    /**
-     * An data entry field that is preserved on a completion item between
-     * a completion and a completion resolve request.
-     *
-     * @var mixed
-     */
-    public $data;
-
-    /**
-     * @param string          $label
-     * @param int|null        $kind
-     * @param string|null     $detail
-     * @param string|null     $documentation
-     * @param string|null     $sortText
-     * @param string|null     $filterText
-     * @param string|null     $insertText
-     * @param TextEdit|null   $textEdit
-     * @param TextEdit[]|null $additionalTextEdits
-     * @param Command|null    $command
-     * @param mixed|null      $data
-     */
-    public function __construct(
-        string $label = null,
-        int $kind = null,
-        string $detail = null,
-        string $documentation = null,
-        string $sortText = null,
-        string $filterText = null,
-        string $insertText = null,
-        TextEdit $textEdit = null,
-        array $additionalTextEdits = null,
-        Command $command = null,
-        $data = null
-    ) {
-        $this->label = $label;
-        $this->kind = $kind;
-        $this->detail = $detail;
-        $this->documentation = $documentation;
-        $this->sortText = $sortText;
-        $this->filterText = $filterText;
-        $this->insertText = $insertText;
-        $this->textEdit = $textEdit;
-        $this->additionalTextEdits = $additionalTextEdits;
-        $this->command = $command;
-        $this->data = $data;
-    }
-
-    /**
-     * Creates a CompletionItem for a Definition
-     *
-     * @param Definition $def
-     * @return self
-     */
-    public static function fromDefinition(Definition $def): self
-    {
-        $item = new CompletionItem;
-        $item->label = $def->symbolInformation->name;
-        $item->kind = CompletionItemKind::fromSymbolKind($def->symbolInformation->kind);
-        if ($def->type) {
-            $item->detail = (string)$def->type;
-        } else if ($def->symbolInformation->containerName) {
-            $item->detail = $def->symbolInformation->containerName;
-        }
-        if ($def->documentation) {
-            $item->documentation = $def->documentation;
-        }
-        if ($def->isStatic && $def->symbolInformation->kind === SymbolKind::PROPERTY) {
-            $item->insertText = '$' . $def->symbolInformation->name;
-        }
-        return $item;
-    }
-}
diff --git a/src/Protocol/CompletionItemKind.php b/src/Protocol/CompletionItemKind.php
deleted file mode 100644
index 046f8ef..0000000
--- a/src/Protocol/CompletionItemKind.php
+++ /dev/null
@@ -1,70 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * The kind of a completion entry.
- */
-abstract class CompletionItemKind
-{
-    const TEXT = 1;
-    const METHOD = 2;
-    const FUNCTION = 3;
-    const CONSTRUCTOR = 4;
-    const FIELD = 5;
-    const VARIABLE = 6;
-    const CLASS_ = 7;
-    const INTERFACE = 8;
-    const MODULE = 9;
-    const PROPERTY = 10;
-    const UNIT = 11;
-    const VALUE = 12;
-    const ENUM = 13;
-    const KEYWORD = 14;
-    const SNIPPET = 15;
-    const COLOR = 16;
-    const FILE = 17;
-    const REFERENCE = 18;
-
-    /**
-     * Returns the CompletionItemKind for a SymbolKind
-     *
-     * @param int $kind A SymbolKind
-     * @return int The CompletionItemKind
-     */
-    public static function fromSymbolKind(int $kind): int
-    {
-        switch ($kind) {
-            case SymbolKind::PROPERTY:
-            case SymbolKind::FIELD:
-                return self::PROPERTY;
-            case SymbolKind::METHOD:
-                return self::METHOD;
-            case SymbolKind::CLASS_:
-                return self::CLASS_;
-            case SymbolKind::INTERFACE:
-                return self::INTERFACE;
-            case SymbolKind::FUNCTION:
-                return self::FUNCTION;
-            case SymbolKind::NAMESPACE:
-            case SymbolKind::MODULE:
-            case SymbolKind::PACKAGE:
-                return self::MODULE;
-            case SymbolKind::FILE:
-                return self::FILE;
-            case SymbolKind::STRING:
-                return self::TEXT;
-            case SymbolKind::NUMBER:
-            case SymbolKind::BOOLEAN:
-            case SymbolKind::ARRAY:
-                return self::VALUE;
-            case SymbolKind::ENUM:
-                return self::ENUM;
-            case SymbolKind::CONSTRUCTOR:
-                return self::CONSTRUCTOR;
-            case SymbolKind::VARIABLE:
-            case SymbolKind::CONSTANT:
-                return self::VARIABLE;
-        }
-    }
-}
diff --git a/src/Protocol/CompletionList.php b/src/Protocol/CompletionList.php
deleted file mode 100644
index 4d0bd64..0000000
--- a/src/Protocol/CompletionList.php
+++ /dev/null
@@ -1,35 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Represents a collection of completion items to be presented in
- * the editor.
- */
-class CompletionList
-{
-    /**
-     * This list it not complete. Further typing should result in recomputing this
-     * list.
-     *
-     * @var bool
-     */
-    public $isIncomplete;
-
-    /**
-     * The completion items.
-     *
-     * @var CompletionItem[]
-     */
-    public $items;
-
-    /**
-     * @param CompletionItem[] $items        The completion items.
-     * @param bool             $isIncomplete This list it not complete. Further typing should result in recomputing this list.
-     */
-    public function __construct(array $items = [], bool $isIncomplete = false)
-    {
-        $this->items = $items;
-        $this->isIncomplete = $isIncomplete;
-    }
-}
diff --git a/src/Protocol/CompletionOptions.php b/src/Protocol/CompletionOptions.php
deleted file mode 100644
index f668ca0..0000000
--- a/src/Protocol/CompletionOptions.php
+++ /dev/null
@@ -1,24 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Completion options.
- */
-class CompletionOptions
-{
-    /*
-     * The server provides support to resolve additional information for a completion
-     * item.
-     *
-     * @var bool|null
-     */
-    public $resolveProvider;
-
-    /**
-     * The characters that trigger completion automatically.
-     *
-     * @var string[]|null
-     */
-    public $triggerCharacters;
-}
diff --git a/src/Protocol/CompletionTriggerKind.php b/src/Protocol/CompletionTriggerKind.php
deleted file mode 100644
index d36129d..0000000
--- a/src/Protocol/CompletionTriggerKind.php
+++ /dev/null
@@ -1,16 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-class CompletionTriggerKind
-{
-    /**
-     * Completion was triggered by invoking it manuall or using API.
-     */
-    const INVOKED = 1;
-
-    /**
-     * Completion was triggered by a trigger character.
-     */
-    const TRIGGER_CHARACTER = 2;
-}
diff --git a/src/Protocol/ContentChangeEvent.php b/src/Protocol/ContentChangeEvent.php
deleted file mode 100644
index ec48bab..0000000
--- a/src/Protocol/ContentChangeEvent.php
+++ /dev/null
@@ -1,31 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * An event describing a change to a text document. If range and rangeLength are
- * omitted the new text is considered to be the full content of the document.
- */
-class ContentChangeEvent
-{
-    /**
-     * The range of the document that changed.
-     *
-     * @var Range|null
-     */
-    public $range;
-
-    /**
-     * The length of the range that got replaced.
-     *
-     * @var int|null
-     */
-    public $rangeLength;
-
-    /**
-     * The new text of the document.
-     *
-     * @var string
-     */
-    public $text;
-}
diff --git a/src/Protocol/DependencyReference.php b/src/Protocol/DependencyReference.php
deleted file mode 100644
index 7dc7b8f..0000000
--- a/src/Protocol/DependencyReference.php
+++ /dev/null
@@ -1,27 +0,0 @@
-<?php
-declare(strict_types = 1);
-
-namespace LanguageServer\Protocol;
-
-class DependencyReference
-{
-    /**
-     * @var mixed
-     */
-    public $hints;
-
-    /**
-     * @var object
-     */
-    public $attributes;
-
-    /**
-     * @param object $attributes
-     * @param mixed  $hints
-     */
-    public function __construct($attributes = null, $hints = null)
-    {
-        $this->attributes = $attributes ?? new \stdClass;
-        $this->hints = $hints;
-    }
-}
diff --git a/src/Protocol/Diagnostic.php b/src/Protocol/Diagnostic.php
deleted file mode 100644
index 7bf9895..0000000
--- a/src/Protocol/Diagnostic.php
+++ /dev/null
@@ -1,63 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Represents a diagnostic, such as a compiler error or warning. Diagnostic objects are only valid in the scope of a
- * resource.
- */
-class Diagnostic
-{
-    /**
-     * The range at which the message applies.
-     *
-     * @var Range
-     */
-    public $range;
-
-    /**
-     * The diagnostic's severity. Can be omitted. If omitted it is up to the
-     * client to interpret diagnostics as error, warning, info or hint.
-     *
-     * @var int|null
-     */
-    public $severity;
-
-    /**
-     * The diagnostic's code. Can be omitted.
-     *
-     * @var int|string|null
-     */
-    public $code;
-
-    /**
-     * A human-readable string describing the source of this
-     * diagnostic, e.g. 'typescript' or 'super lint'.
-     *
-     * @var string|null
-     */
-    public $source;
-
-    /**
-     * The diagnostic's message.
-     *
-     * @var string
-     */
-    public $message;
-
-    /**
-     * @param  string $message  The diagnostic's message
-     * @param  Range  $range    The range at which the message applies
-     * @param  int    $code     The diagnostic's code
-     * @param  int    $severity DiagnosticSeverity
-     * @param  string $source   A human-readable string describing the source of this diagnostic
-     */
-    public function __construct(string $message = null, Range $range = null, int $code = null, int $severity = null, string $source = null)
-    {
-        $this->message = $message;
-        $this->range = $range;
-        $this->code = $code;
-        $this->severity = $severity;
-        $this->source = $source;
-    }
-}
diff --git a/src/Protocol/DiagnosticSeverity.php b/src/Protocol/DiagnosticSeverity.php
deleted file mode 100644
index e91da8f..0000000
--- a/src/Protocol/DiagnosticSeverity.php
+++ /dev/null
@@ -1,26 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-abstract class DiagnosticSeverity
-{
-    /**
-     * Reports an error.
-     */
-    const ERROR = 1;
-
-    /**
-     * Reports a warning.
-     */
-    const WARNING = 2;
-
-    /**
-     * Reports an information.
-     */
-    const INFORMATION = 3;
-
-    /**
-     * Reports a hint.
-     */
-    const HINT = 4;
-}
diff --git a/src/Protocol/DocumentHighlight.php b/src/Protocol/DocumentHighlight.php
deleted file mode 100644
index 167d45a..0000000
--- a/src/Protocol/DocumentHighlight.php
+++ /dev/null
@@ -1,25 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * A document highlight is a range inside a text document which deserves
- * special attention. Usually a document highlight is visualized by changing
- * the background color of its range.
- */
-class DocumentHighlight
-{
-    /**
-     * The range this highlight applies to.
-     *
-     * @var Range
-     */
-    public $range;
-
-    /**
-     * The highlight kind, default is DocumentHighlightKind::TEXT.
-     *
-     * @var int|null
-     */
-    public $kind;
-}
diff --git a/src/Protocol/DocumentHighlightKind.php b/src/Protocol/DocumentHighlightKind.php
deleted file mode 100644
index 14e701a..0000000
--- a/src/Protocol/DocumentHighlightKind.php
+++ /dev/null
@@ -1,24 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * A document highlight kind.
- */
-abstract class DocumentHighlightKind
-{
-    /**
-     * A textual occurrance.
-     */
-    const TEXT = 1;
-
-    /**
-     * Read-access of a symbol, like reading a variable.
-     */
-    const READ = 2;
-
-    /**
-     * Write-access of a symbol, like writing to a variable.
-     */
-    const WRITE = 3;
-}
diff --git a/src/Protocol/DocumentOnTypeFormattingOptions.php b/src/Protocol/DocumentOnTypeFormattingOptions.php
deleted file mode 100644
index 875da9c..0000000
--- a/src/Protocol/DocumentOnTypeFormattingOptions.php
+++ /dev/null
@@ -1,23 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Format document on type options
- */
-class DocumentOnTypeFormattingOptions
-{
-    /**
-     * A character on which formatting should be triggered, like `}`.
-     *
-     * @var string
-     */
-    public $firstTriggerCharacter;
-
-    /**
-     * More trigger characters.
-     *
-     * @var string[]|null
-     */
-    public $moreTriggerCharacter;
-}
diff --git a/src/Protocol/ErrorCode.php b/src/Protocol/ErrorCode.php
deleted file mode 100644
index 51d88c7..0000000
--- a/src/Protocol/ErrorCode.php
+++ /dev/null
@@ -1,17 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Enum
- */
-abstract class ErrorCode
-{
-    const PARSE_ERROR = -32700;
-    const INVALID_REQUEST = -32600;
-    const METHOD_NOT_FOUND = -32601;
-    const INVALID_PARAMS = -32602;
-    const INTERNAL_ERROR = -32603;
-    const SERVER_ERROR_START = -32099;
-    const SERVER_ERROR_END = -32000;
-}
diff --git a/src/Protocol/FileChangeType.php b/src/Protocol/FileChangeType.php
deleted file mode 100644
index 631c4e7..0000000
--- a/src/Protocol/FileChangeType.php
+++ /dev/null
@@ -1,24 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * The file event type. Enum
- */
-abstract class FileChangeType
-{
-    /**
-     * The file got created.
-     */
-    const CREATED = 1;
-
-    /**
-     * The file got changed.
-     */
-    const CHANGED = 2;
-
-    /**
-     * The file got deleted.
-     */
-    const DELETED = 3;
-}
diff --git a/src/Protocol/FileEvent.php b/src/Protocol/FileEvent.php
deleted file mode 100644
index 015044d..0000000
--- a/src/Protocol/FileEvent.php
+++ /dev/null
@@ -1,33 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * An event describing a file change.
- */
-class FileEvent
-{
-    /**
-     * The file's URI.
-     *
-     * @var string
-     */
-    public $uri;
-
-    /**
-     * The change type.
-     *
-     * @var int
-     */
-    public $type;
-
-    /**
-     * @param string $uri
-     * @param int $type
-     */
-    public function __construct(string $uri, int $type)
-    {
-        $this->uri = $uri;
-        $this->type = $type;
-    }
-}
diff --git a/src/Protocol/FormattingOptions.php b/src/Protocol/FormattingOptions.php
deleted file mode 100644
index b672ddf..0000000
--- a/src/Protocol/FormattingOptions.php
+++ /dev/null
@@ -1,25 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Value-object describing what options formatting should use.
- */
-class FormattingOptions
-{
-    /**
-     * Size of a tab in spaces.
-     *
-     * @var int
-     */
-    public $tabSize;
-
-    /**
-     * Prefer spaces over tabs.
-     *
-     * @var bool
-     */
-    public $insertSpaces;
-
-    // Can be extended with further properties.
-}
diff --git a/src/Protocol/Hover.php b/src/Protocol/Hover.php
deleted file mode 100644
index 6e7656e..0000000
--- a/src/Protocol/Hover.php
+++ /dev/null
@@ -1,33 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * The result of a hover request.
- */
-class Hover
-{
-    /**
-     * The hover's content
-     *
-     * @var string|MarkedString|string[]|MarkedString[]
-     */
-    public $contents;
-
-    /**
-     * An optional range
-     *
-     * @var Range|null
-     */
-    public $range;
-
-    /**
-     * @param string|MarkedString|string[]|MarkedString[] $contents The hover's content
-     * @param Range $range An optional range
-     */
-    public function __construct($contents = null, $range = null)
-    {
-        $this->contents = $contents;
-        $this->range = $range;
-    }
-}
diff --git a/src/Protocol/InitializeResult.php b/src/Protocol/InitializeResult.php
deleted file mode 100644
index 4a18e82..0000000
--- a/src/Protocol/InitializeResult.php
+++ /dev/null
@@ -1,21 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-class InitializeResult
-{
-    /**
-     * The capabilities the language server provides.
-     *
-     * @var LanguageServer\Protocol\ServerCapabilities
-     */
-    public $capabilities;
-
-    /**
-     * @param LanguageServer\Protocol\ServerCapabilities $capabilities
-     */
-    public function __construct(ServerCapabilities $capabilities = null)
-    {
-        $this->capabilities = $capabilities ?? new ServerCapabilities();
-    }
-}
diff --git a/src/Protocol/Location.php b/src/Protocol/Location.php
deleted file mode 100644
index 50fedfa..0000000
--- a/src/Protocol/Location.php
+++ /dev/null
@@ -1,43 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-use Microsoft\PhpParser;
-use Microsoft\PhpParser\Node;
-
-/**
- * Represents a location inside a resource, such as a line inside a text file.
- */
-class Location
-{
-    /**
-     * @var string
-     */
-    public $uri;
-
-    /**
-     * @var Range
-     */
-    public $range;
-
-    /**
-     * Returns the location of the node
-     *
-     * @param Node $node
-     * @return self
-     */
-    public static function fromNode($node)
-    {
-        $range = PhpParser\PositionUtilities::getRangeFromPosition($node->getStart(), $node->getWidth(), $node->getFileContents());
-        return new self($node->getUri(), new Range(
-            new Position($range->start->line, $range->start->character),
-            new Position($range->end->line, $range->end->character)
-        ));
-    }
-
-    public function __construct(string $uri = null, Range $range = null)
-    {
-        $this->uri = $uri;
-        $this->range = $range;
-    }
-}
diff --git a/src/Protocol/MarkedString.php b/src/Protocol/MarkedString.php
deleted file mode 100644
index 0799f14..0000000
--- a/src/Protocol/MarkedString.php
+++ /dev/null
@@ -1,22 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-class MarkedString
-{
-    /**
-     * @var string
-     */
-    public $language;
-
-    /**
-     * @var string
-     */
-    public $value;
-
-    public function __construct(string $language = null, string $value = null)
-    {
-        $this->language = $language;
-        $this->value = $value;
-    }
-}
diff --git a/src/Protocol/MessageActionItem.php b/src/Protocol/MessageActionItem.php
deleted file mode 100644
index 59dafe5..0000000
--- a/src/Protocol/MessageActionItem.php
+++ /dev/null
@@ -1,13 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-class MessageActionItem
-{
-    /**
-     * A short title like 'Retry', 'Open Log' etc.
-     *
-     * @var string
-     */
-    public $title;
-}
diff --git a/src/Protocol/MessageType.php b/src/Protocol/MessageType.php
deleted file mode 100644
index 6def9e9..0000000
--- a/src/Protocol/MessageType.php
+++ /dev/null
@@ -1,29 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Enum
- */
-abstract class MessageType
-{
-    /**
-     * An error message.
-     */
-    const ERROR = 1;
-
-    /**
-     * A warning message.
-     */
-    const WARNING = 2;
-
-    /**
-     * An information message.
-     */
-    const INFO = 3;
-
-    /**
-     * A log message.
-     */
-    const LOG = 4;
-}
diff --git a/src/Protocol/PackageDescriptor.php b/src/Protocol/PackageDescriptor.php
deleted file mode 100644
index e635740..0000000
--- a/src/Protocol/PackageDescriptor.php
+++ /dev/null
@@ -1,25 +0,0 @@
-<?php
-declare(strict_types = 1);
-
-namespace LanguageServer\Protocol;
-
-/**
- * Uniquely identifies a Composer package
- */
-class PackageDescriptor
-{
-    /**
-     * The package name
-     *
-     * @var string
-     */
-    public $name;
-
-    /**
-     * @param string $name The package name
-     */
-    public function __construct(string $name = null)
-    {
-        $this->name = $name;
-    }
-}
diff --git a/src/Protocol/ParameterInformation.php b/src/Protocol/ParameterInformation.php
deleted file mode 100644
index fa9b7bf..0000000
--- a/src/Protocol/ParameterInformation.php
+++ /dev/null
@@ -1,39 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Represents a parameter of a callable-signature. A parameter can
- * have a label and a doc-comment.
- */
-class ParameterInformation
-{
-    /**
-     * The label of this signature. Will be shown in
-     * the UI.
-     *
-     * @var string
-     */
-    public $label;
-
-    /**
-     * The human-readable doc-comment of this signature. Will be shown
-     * in the UI but can be omitted.
-     *
-     * @var string|null
-     */
-    public $documentation;
-
-    /**
-     * Create ParameterInformation
-     *
-     * @param string $label         The label of this signature. Will be shown in the UI.
-     * @param string $documentation The human-readable doc-comment of this signature. Will be shown in the UI but can
-     *                              be omitted.
-     */
-    public function __construct(string $label, string $documentation = null)
-    {
-        $this->label = $label;
-        $this->documentation = $documentation;
-    }
-}
diff --git a/src/Protocol/Position.php b/src/Protocol/Position.php
deleted file mode 100644
index f47afe2..0000000
--- a/src/Protocol/Position.php
+++ /dev/null
@@ -1,65 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Position in a text document expressed as zero-based line and character offset.
- */
-class Position
-{
-    /**
-     * Line position in a document (zero-based).
-     *
-     * @var int
-     */
-    public $line;
-
-    /**
-     * Character offset on a line in a document (zero-based).
-     *
-     * @var int
-     */
-    public $character;
-
-    public function __construct(int $line = null, int $character = null)
-    {
-        $this->line = $line;
-        $this->character = $character;
-    }
-
-    /**
-     * Compares this position to another position
-     * Returns
-     *  - 0 if the positions match
-     *  - a negative number if $this is before $position
-     *  - a positive number otherwise
-     *
-     * @param Position $position
-     * @return int
-     */
-    public function compare(Position $position): int
-    {
-        if ($this->line === $position->line && $this->character === $position->character) {
-            return 0;
-        }
-
-        if ($this->line !== $position->line) {
-            return $this->line - $position->line;
-        }
-
-        return $this->character - $position->character;
-    }
-
-    /**
-     * Returns the offset of the position in a string
-     *
-     * @param string $content
-     * @return int
-     */
-    public function toOffset(string $content): int
-    {
-        $lines = explode("\n", $content);
-        $slice = array_slice($lines, 0, $this->line);
-        return array_sum(array_map('strlen', $slice)) + count($slice) + $this->character;
-    }
-}
diff --git a/src/Protocol/Range.php b/src/Protocol/Range.php
deleted file mode 100644
index 1e19a5a..0000000
--- a/src/Protocol/Range.php
+++ /dev/null
@@ -1,59 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-use Microsoft\PhpParser;
-use Microsoft\PhpParser\Node;
-
-/**
- * A range in a text document expressed as (zero-based) start and end positions.
- */
-class Range
-{
-    /**
-     * The range's start position.
-     *
-     * @var Position
-     */
-    public $start;
-
-    /**
-     * The range's end position.
-     *
-     * @var Position
-     */
-    public $end;
-
-    /**
-     * Returns the range the node spans
-     *
-     * @param Node $node
-     * @return self
-     */
-    public static function fromNode(Node $node)
-    {
-        $range = PhpParser\PositionUtilities::getRangeFromPosition($node->getStart(), $node->getWidth(), $node->getFileContents());
-
-        return new self(
-            new Position($range->start->line, $range->start->character),
-            new Position($range->end->line, $range->end->character)
-        );
-    }
-
-    public function __construct(Position $start = null, Position $end = null)
-    {
-        $this->start = $start;
-        $this->end = $end;
-    }
-
-    /**
-     * Checks if a position is within the range
-     *
-     * @param Position $position
-     * @return bool
-     */
-    public function includes(Position $position): bool
-    {
-        return $this->start->compare($position) <= 0 && $this->end->compare($position) >= 0;
-    }
-}
diff --git a/src/Protocol/ReferenceContext.php b/src/Protocol/ReferenceContext.php
deleted file mode 100644
index bd546d5..0000000
--- a/src/Protocol/ReferenceContext.php
+++ /dev/null
@@ -1,13 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-class ReferenceContext
-{
-    /**
-     * Include the declaration of the current symbol.
-     *
-     * @var bool
-     */
-    public $includeDeclaration;
-}
diff --git a/src/Protocol/ReferenceInformation.php b/src/Protocol/ReferenceInformation.php
deleted file mode 100644
index e66f1fa..0000000
--- a/src/Protocol/ReferenceInformation.php
+++ /dev/null
@@ -1,36 +0,0 @@
-<?php
-declare(strict_types = 1);
-
-namespace LanguageServer\Protocol;
-
-/**
- * Metadata about the symbol that can be used to identify or locate its
- * definition.
- */
-class ReferenceInformation
-{
-    /**
-     * The location in the workspace where the `symbol` is referenced.
-     *
-     * @var Location
-     */
-    public $reference;
-
-    /**
-     * Metadata about the symbol that can be used to identify or locate its
-     * definition.
-     *
-     * @var SymbolDescriptor
-     */
-    public $symbol;
-
-    /**
-     * @param Location         $reference The location in the workspace where the `symbol` is referenced.
-     * @param SymbolDescriptor $symbol    Metadata about the symbol that can be used to identify or locate its definition.
-     */
-    public function __construct(Location $reference = null, SymbolDescriptor $symbol = null)
-    {
-        $this->reference = $reference;
-        $this->symbol = $symbol;
-    }
-}
diff --git a/src/Protocol/ServerCapabilities.php b/src/Protocol/ServerCapabilities.php
deleted file mode 100644
index 1893a51..0000000
--- a/src/Protocol/ServerCapabilities.php
+++ /dev/null
@@ -1,132 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-class ServerCapabilities
-{
-    /**
-     * Defines how text documents are synced.
-     *
-     * @var int|null
-     */
-    public $textDocumentSync;
-
-    /**
-     * The server provides hover support.
-     *
-     * @var bool|null
-     */
-    public $hoverProvider;
-
-    /**
-     * The server provides completion support.
-     *
-     * @var CompletionOptions|null
-     */
-    public $completionProvider;
-
-    /**
-     * The server provides signature help support.
-     *
-     * @var SignatureHelpOptions|null
-     */
-    public $signatureHelpProvider;
-
-    /**
-     * The server provides goto definition support.
-     *
-     * @var bool|null
-     */
-    public $definitionProvider;
-
-    /**
-     * The server provides find references support.
-     *
-     * @var bool|null
-     */
-    public $referencesProvider;
-
-    /**
-     * The server provides document highlight support.
-     *
-     * @var bool|null
-     */
-    public $documentHighlightProvider;
-
-    /**
-     * The server provides document symbol support.
-     *
-     * @var bool|null
-     */
-    public $documentSymbolProvider;
-
-    /**
-     * The server provides workspace symbol support.
-     *
-     * @var bool|null
-     */
-    public $workspaceSymbolProvider;
-
-    /**
-     * The server provides code actions.
-     *
-     * @var bool|null
-     */
-    public $codeActionProvider;
-
-    /**
-     * The server provides code lens.
-     *
-     * @var CodeLensOptions|null
-     */
-    public $codeLensProvider;
-
-    /**
-     * The server provides document formatting.
-     *
-     * @var bool|null
-     */
-    public $documentFormattingProvider;
-
-    /**
-     * The server provides document range formatting.
-     *
-     * @var bool|null
-     */
-    public $documentRangeFormattingProvider;
-
-    /**
-     * The server provides document formatting on typing.
-     *
-     * @var DocumentOnTypeFormattingOptions|null
-     */
-    public $documentOnTypeFormattingProvider;
-
-    /**
-     * The server provides rename support.
-     *
-     * @var bool|null
-     */
-    public $renameProvider;
-
-    /**
-     * The server provides workspace references exporting support.
-     *
-     * @var bool|null
-     */
-    public $xworkspaceReferencesProvider;
-
-    /**
-     * The server provides extended text document definition support.
-     *
-     * @var bool|null
-     */
-    public $xdefinitionProvider;
-
-    /**
-     * The server provides workspace dependencies support.
-     *
-     * @var bool|null
-     */
-    public $dependenciesProvider;
-}
diff --git a/src/Protocol/SignatureHelp.php b/src/Protocol/SignatureHelp.php
deleted file mode 100644
index f7aec6f..0000000
--- a/src/Protocol/SignatureHelp.php
+++ /dev/null
@@ -1,46 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Signature help represents the signature of something
- * callable. There can be multiple signature but only one
- * active and only one active parameter.
- */
-class SignatureHelp
-{
-    /**
-     * One or more signatures.
-     *
-     * @var SignatureInformation[]
-     */
-    public $signatures;
-
-    /**
-     * The active signature.
-     *
-     * @var int|null
-     */
-    public $activeSignature;
-
-    /**
-     * The active parameter of the active signature.
-     *
-     * @var int|null
-     */
-    public $activeParameter;
-
-    /**
-     * Create a SignatureHelp
-     *
-     * @param SignatureInformation[] $signatures      List of signature information
-     * @param int|null               $activeSignature The active signature, zero based
-     * @param int|null               $activeParameter The active parameter, zero based
-     */
-    public function __construct(array $signatures = [], $activeSignature = null, int $activeParameter = null)
-    {
-        $this->signatures = $signatures;
-        $this->activeSignature = $activeSignature;
-        $this->activeParameter = $activeParameter;
-    }
-}
diff --git a/src/Protocol/SignatureHelpOptions.php b/src/Protocol/SignatureHelpOptions.php
deleted file mode 100644
index 25b0e37..0000000
--- a/src/Protocol/SignatureHelpOptions.php
+++ /dev/null
@@ -1,16 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Signature help options.
- */
-class SignatureHelpOptions
-{
-    /**
-     * The characters that trigger signature help automatically.
-     *
-     * @var string[]|null
-     */
-    public $triggerCharacters;
-}
diff --git a/src/Protocol/SignatureInformation.php b/src/Protocol/SignatureInformation.php
deleted file mode 100644
index d545f65..0000000
--- a/src/Protocol/SignatureInformation.php
+++ /dev/null
@@ -1,49 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Represents the signature of something callable. A signature
- * can have a label, like a function-name, a doc-comment, and
- * a set of parameters.
- */
-class SignatureInformation
-{
-    /**
-     * The label of this signature. Will be shown in
-     * the UI.
-     *
-     * @var string
-     */
-    public $label;
-
-    /**
-     * The human-readable doc-comment of this signature. Will be shown
-     * in the UI but can be omitted.
-     *
-     * @var string|null
-     */
-    public $documentation;
-
-    /**
-     * The parameters of this signature.
-     *
-     * @var ParameterInformation[]|null
-     */
-    public $parameters;
-
-    /**
-     * Create a SignatureInformation
-     *
-     * @param string $label               The label of this signature. Will be shown in the UI.
-     * @param ParameterInformation[]|null The parameters of this signature
-     * @param string|null                 The human-readable doc-comment of this signature. Will be shown in the UI
-     *                                    but can be omitted.
-     */
-    public function __construct(string $label, array $parameters = null, string $documentation = null)
-    {
-        $this->label = $label;
-        $this->parameters = $parameters;
-        $this->documentation = $documentation;
-    }
-}
diff --git a/src/Protocol/SymbolDescriptor.php b/src/Protocol/SymbolDescriptor.php
deleted file mode 100644
index 4116864..0000000
--- a/src/Protocol/SymbolDescriptor.php
+++ /dev/null
@@ -1,34 +0,0 @@
-<?php
-declare(strict_types = 1);
-
-namespace LanguageServer\Protocol;
-
-/**
- * Uniquely identifies a symbol
- */
-class SymbolDescriptor
-{
-    /**
-     * The fully qualified structural element name, a globally unique identifier for the symbol.
-     *
-     * @var string
-     */
-    public $fqsen;
-
-    /**
-     * Identifies the Composer package the symbol is defined in (if any)
-     *
-     * @var PackageDescriptor|null
-     */
-    public $package;
-
-    /**
-     * @param string $fqsen              The fully qualified structural element name, a globally unique identifier for the symbol.
-     * @param PackageDescriptor $package Identifies the Composer package the symbol is defined in
-     */
-    public function __construct(string $fqsen = null, PackageDescriptor $package = null)
-    {
-        $this->fqsen = $fqsen;
-        $this->package = $package;
-    }
-}
diff --git a/src/Protocol/SymbolKind.php b/src/Protocol/SymbolKind.php
deleted file mode 100644
index e8a44e2..0000000
--- a/src/Protocol/SymbolKind.php
+++ /dev/null
@@ -1,28 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * A symbol kind.
- */
-abstract class SymbolKind
-{
-    const FILE = 1;
-    const MODULE = 2;
-    const NAMESPACE = 3;
-    const PACKAGE = 4;
-    const CLASS_ = 5;
-    const METHOD = 6;
-    const PROPERTY = 7;
-    const FIELD = 8;
-    const CONSTRUCTOR = 9;
-    const ENUM = 10;
-    const INTERFACE = 11;
-    const FUNCTION = 12;
-    const VARIABLE = 13;
-    const CONSTANT = 14;
-    const STRING = 15;
-    const NUMBER = 16;
-    const BOOLEAN = 17;
-    const ARRAY = 18;
-}
diff --git a/src/Protocol/SymbolLocationInformation.php b/src/Protocol/SymbolLocationInformation.php
deleted file mode 100644
index 4009879..0000000
--- a/src/Protocol/SymbolLocationInformation.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php
-declare(strict_types = 1);
-
-namespace LanguageServer\Protocol;
-
-class SymbolLocationInformation
-{
-    /**
-     * The location where the symbol is defined, if any.
-     *
-     * @var Location|null
-     */
-    public $location;
-
-    /**
-     * Metadata about the symbol that can be used to identify or locate its
-     * definition.
-     *
-     * @var SymbolDescriptor
-     */
-    public $symbol;
-
-    /**
-     * @param SymbolDescriptor $symbol   The location where the symbol is defined, if any
-     * @param Location         $location Metadata about the symbol that can be used to identify or locate its definition
-     */
-    public function __construct(SymbolDescriptor $symbol = null, Location $location = null)
-    {
-        $this->symbol = $symbol;
-        $this->location = $location;
-    }
-}
diff --git a/src/Protocol/TextDocumentContentChangeEvent.php b/src/Protocol/TextDocumentContentChangeEvent.php
deleted file mode 100644
index 9cfa08b..0000000
--- a/src/Protocol/TextDocumentContentChangeEvent.php
+++ /dev/null
@@ -1,31 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * An event describing a change to a text document. If range and rangeLength are omitted
- * the new text is considered to be the full content of the document.
- */
-class TextDocumentContentChangeEvent
-{
-    /**
-     * The range of the document that changed.
-     *
-     * @var Range|null
-     */
-    public $range;
-
-    /**
-     * The length of the range that got replaced.
-     *
-     * @var int|null
-     */
-    public $rangeLength;
-
-    /**
-     * The new text of the document.
-     *
-     * @var string
-     */
-    public $text;
-}
diff --git a/src/Protocol/TextDocumentIdentifier.php b/src/Protocol/TextDocumentIdentifier.php
deleted file mode 100644
index d19e3cf..0000000
--- a/src/Protocol/TextDocumentIdentifier.php
+++ /dev/null
@@ -1,21 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-class TextDocumentIdentifier
-{
-    /**
-     * The text document's URI.
-     *
-     * @var string
-     */
-    public $uri;
-
-    /**
-     * @param string $uri The text document's URI.
-     */
-    public function __construct(string $uri = null)
-    {
-        $this->uri = $uri;
-    }
-}
diff --git a/src/Protocol/TextDocumentItem.php b/src/Protocol/TextDocumentItem.php
deleted file mode 100644
index 0c86664..0000000
--- a/src/Protocol/TextDocumentItem.php
+++ /dev/null
@@ -1,38 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * An item to transfer a text document from the client to the server.
- */
-class TextDocumentItem
-{
-    /**
-     * The text document's URI.
-     *
-     * @var string
-     */
-    public $uri;
-
-    /**
-     * The text document's language identifier.
-     *
-     * @var string
-     */
-    public $languageId;
-
-    /**
-     * The version number of this document (it will strictly increase after each
-     * change, including undo/redo).
-     *
-     * @var int
-     */
-    public $version;
-
-    /**
-     * The content of the opened text document.
-     *
-     * @var string
-     */
-    public $text;
-}
diff --git a/src/Protocol/TextDocumentSyncKind.php b/src/Protocol/TextDocumentSyncKind.php
deleted file mode 100644
index 313e29d..0000000
--- a/src/Protocol/TextDocumentSyncKind.php
+++ /dev/null
@@ -1,25 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * Defines how the host (editor) should sync document changes to the language server.
- */
-abstract class TextDocumentSyncKind
-{
-    /**
-     * Documents should not be synced at all.
-     */
-    const NONE = 0;
-
-    /**
-     * Documents are synced by always sending the full content of the document.
-     */
-    const FULL = 1;
-
-    /*
-     * Documents are synced by sending the full content on open. After that only
-     * incremental updates to the document are sent.
-     */
-    const INCREMENTAL = 2;
-}
diff --git a/src/Protocol/TextEdit.php b/src/Protocol/TextEdit.php
deleted file mode 100644
index 8ca1d43..0000000
--- a/src/Protocol/TextEdit.php
+++ /dev/null
@@ -1,31 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * A textual edit applicable to a text document.
- */
-class TextEdit
-{
-    /**
-     * The range of the text document to be manipulated. To insert
-     * text into a document create a range where start === end.
-     *
-     * @var Range
-     */
-    public $range;
-
-    /**
-     * The string to be inserted. For delete operations use an
-     * empty string.
-     *
-     * @var string
-     */
-    public $newText;
-
-    public function __construct(Range $range = null, string $newText = null)
-    {
-        $this->range = $range;
-        $this->newText = $newText;
-    }
-}
diff --git a/src/Protocol/VersionedTextDocumentIdentifier.php b/src/Protocol/VersionedTextDocumentIdentifier.php
deleted file mode 100644
index ba74e42..0000000
--- a/src/Protocol/VersionedTextDocumentIdentifier.php
+++ /dev/null
@@ -1,13 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-class VersionedTextDocumentIdentifier extends TextDocumentIdentifier
-{
-    /**
-     * The version number of this document.
-     *
-     * @var int
-     */
-    public $version;
-}
diff --git a/src/Protocol/WorkspaceEdit.php b/src/Protocol/WorkspaceEdit.php
deleted file mode 100644
index 7414dd0..0000000
--- a/src/Protocol/WorkspaceEdit.php
+++ /dev/null
@@ -1,16 +0,0 @@
-<?php
-
-namespace LanguageServer\Protocol;
-
-/**
- * A workspace edit represents changes to many resources managed in the workspace.
- */
-class WorkspaceEdit
-{
-    /**
-     * Holds changes to existing resources. Associative Array from URI to TextEdit
-     *
-     * @var TextEdit[]
-     */
-    public $changes;
-}
diff --git a/src/ProtocolStreamReader.php b/src/ProtocolStreamReader.php
index 4071dcd..ecb4ae1 100644
--- a/src/ProtocolStreamReader.php
+++ b/src/ProtocolStreamReader.php
@@ -3,7 +3,7 @@ declare(strict_types = 1);
 
 namespace LanguageServer;
 
-use LanguageServer\Protocol\Message;
+use LanguageServer\Message;
 use AdvancedJsonRpc\Message as MessageBody;
 use Sabre\Event\{Loop, Emitter};
 
diff --git a/src/ProtocolStreamWriter.php b/src/ProtocolStreamWriter.php
index f004a5f..166ea90 100644
--- a/src/ProtocolStreamWriter.php
+++ b/src/ProtocolStreamWriter.php
@@ -3,7 +3,7 @@ declare(strict_types = 1);
 
 namespace LanguageServer;
 
-use LanguageServer\Protocol\Message;
+use LanguageServer\Message;
 use Sabre\Event\{
     Loop,
     Promise
diff --git a/src/ProtocolWriter.php b/src/ProtocolWriter.php
index 5ac237c..ac25218 100644
--- a/src/ProtocolWriter.php
+++ b/src/ProtocolWriter.php
@@ -3,7 +3,7 @@ declare(strict_types = 1);
 
 namespace LanguageServer;
 
-use LanguageServer\Protocol\Message;
+use LanguageServer\Message;
 use Sabre\Event\Promise;
 
 interface ProtocolWriter
diff --git a/src/Server/TextDocument.php b/src/Server/TextDocument.php
index e5657b3..039ff57 100644
--- a/src/Server/TextDocument.php
+++ b/src/Server/TextDocument.php
@@ -7,7 +7,9 @@ use LanguageServer\{
     CompletionProvider, SignatureHelpProvider, LanguageClient, PhpDocument, PhpDocumentLoader, DefinitionResolver
 };
 use LanguageServer\Index\ReadableIndex;
-use LanguageServer\Protocol\{
+use LanguageServer\Factory\LocationFactory;
+use LanguageServer\Factory\RangeFactory;
+use LanguageServerProtocol\{
     FormattingOptions,
     Hover,
     Location,
@@ -108,7 +110,7 @@ class TextDocument
      * The document symbol request is sent from the client to the server to list all symbols found in a given text
      * document.
      *
-     * @param \LanguageServer\Protocol\TextDocumentIdentifier $textDocument
+     * @param \LanguageServerProtocol\TextDocumentIdentifier $textDocument
      * @return Promise <SymbolInformation[]>
      */
     public function documentSymbol(TextDocumentIdentifier $textDocument): Promise
@@ -127,7 +129,7 @@ class TextDocument
      * document's truth is now managed by the client and the server must not try to read the document's truth using the
      * document's uri.
      *
-     * @param \LanguageServer\Protocol\TextDocumentItem $textDocument The document that was opened.
+     * @param \LanguageServerProtocol\TextDocumentItem $textDocument The document that was opened.
      * @return void
      */
     public function didOpen(TextDocumentItem $textDocument)
@@ -141,8 +143,8 @@ class TextDocument
     /**
      * The document change notification is sent from the client to the server to signal changes to a text document.
      *
-     * @param \LanguageServer\Protocol\VersionedTextDocumentIdentifier $textDocument
-     * @param \LanguageServer\Protocol\TextDocumentContentChangeEvent[] $contentChanges
+     * @param \LanguageServerProtocol\VersionedTextDocumentIdentifier $textDocument
+     * @param \LanguageServerProtocol\TextDocumentContentChangeEvent[] $contentChanges
      * @return void
      */
     public function didChange(VersionedTextDocumentIdentifier $textDocument, array $contentChanges)
@@ -157,7 +159,7 @@ class TextDocument
      * The document's truth now exists where the document's uri points to (e.g. if the document's uri is a file uri the
      * truth now exists on disk).
      *
-     * @param \LanguageServer\Protocol\TextDocumentIdentifier $textDocument The document that was closed
+     * @param \LanguageServerProtocol\TextDocumentIdentifier $textDocument The document that was closed
      * @return void
      */
     public function didClose(TextDocumentIdentifier $textDocument)
@@ -208,7 +210,7 @@ class TextDocument
                     if ($descendantNode instanceof Node\Expression\Variable &&
                         $descendantNode->getName() === $node->getName()
                     ) {
-                        $locations[] = Location::fromNode($descendantNode);
+                        $locations[] = LocationFactory::fromNode($descendantNode);
                     }
                 }
             } else {
@@ -225,15 +227,16 @@ class TextDocument
                         return [];
                     }
                 }
-                $refDocuments = yield Promise\all(array_map(
-                    [$this->documentLoader, 'getOrLoad'],
-                    $this->index->getReferenceUris($fqn)
-                ));
+                $refDocumentPromises = [];
+                foreach ($this->index->getReferenceUris($fqn) as $uri) {
+                    $refDocumentPromises[] = $this->documentLoader->getOrLoad($uri);
+                }
+                $refDocuments = yield Promise\all($refDocumentPromises);
                 foreach ($refDocuments as $document) {
                     $refs = $document->getReferenceNodesByFqn($fqn);
                     if ($refs !== null) {
                         foreach ($refs as $ref) {
-                            $locations[] = Location::fromNode($ref);
+                            $locations[] = LocationFactory::fromNode($ref);
                         }
                     }
                 }
@@ -332,7 +335,7 @@ class TextDocument
                 }
                 yield waitForEvent($this->index, 'definition-added');
             }
-            $range = Range::fromNode($node);
+            $range = RangeFactory::fromNode($node);
             if ($def === null) {
                 return new Hover([], $range);
             }
diff --git a/src/Server/Workspace.php b/src/Server/Workspace.php
index 548197b..fd93a9e 100644
--- a/src/Server/Workspace.php
+++ b/src/Server/Workspace.php
@@ -5,7 +5,8 @@ namespace LanguageServer\Server;
 
 use LanguageServer\{LanguageClient, PhpDocumentLoader};
 use LanguageServer\Index\{ProjectIndex, DependenciesIndex, Index};
-use LanguageServer\Protocol\{
+use LanguageServer\Factory\LocationFactory;
+use LanguageServerProtocol\{
     FileChangeType,
     FileEvent,
     SymbolInformation,
@@ -150,7 +151,7 @@ class Workspace
                     $doc = yield $this->documentLoader->getOrLoad($uri);
                     foreach ($doc->getReferenceNodesByFqn($fqn) as $node) {
                         $refInfo = new ReferenceInformation;
-                        $refInfo->reference = Location::fromNode($node);
+                        $refInfo->reference = LocationFactory::fromNode($node);
                         $refInfo->symbol = $query;
                         $refInfos[] = $refInfo;
                     }
diff --git a/src/SignatureHelpProvider.php b/src/SignatureHelpProvider.php
index 92775be..66afd5f 100644
--- a/src/SignatureHelpProvider.php
+++ b/src/SignatureHelpProvider.php
@@ -4,7 +4,7 @@ declare(strict_types = 1);
 namespace LanguageServer;
 
 use LanguageServer\Index\ReadableIndex;
-use LanguageServer\Protocol\{
+use LanguageServerProtocol\{
     Position,
     SignatureHelp
 };
diff --git a/src/SignatureInformationFactory.php b/src/SignatureInformationFactory.php
index 6b8a1f0..86402b6 100644
--- a/src/SignatureInformationFactory.php
+++ b/src/SignatureInformationFactory.php
@@ -3,7 +3,7 @@ declare(strict_types = 1);
 
 namespace LanguageServer;
 
-use LanguageServer\Protocol\{SignatureInformation, ParameterInformation};
+use LanguageServerProtocol\{SignatureInformation, ParameterInformation};
 use Microsoft\PhpParser\FunctionLike;
 
 class SignatureInformationFactory
diff --git a/src/TreeAnalyzer.php b/src/TreeAnalyzer.php
index 03ad539..6b48470 100644
--- a/src/TreeAnalyzer.php
+++ b/src/TreeAnalyzer.php
@@ -3,7 +3,8 @@ declare(strict_types = 1);
 
 namespace LanguageServer;
 
-use LanguageServer\Protocol\{Diagnostic, DiagnosticSeverity, Range, Position};
+use LanguageServer\Factory\RangeFactory;
+use LanguageServerProtocol\{Diagnostic, DiagnosticSeverity, Range, Position};
 use phpDocumentor\Reflection\DocBlockFactory;
 use Microsoft\PhpParser;
 use Microsoft\PhpParser\Node;
@@ -100,7 +101,7 @@ class TreeAnalyzer
             if ($method && $method->isStatic()) {
                 $this->diagnostics[] = new Diagnostic(
                     "\$this can not be used in static methods.",
-                    Range::fromNode($node),
+                    RangeFactory::fromNode($node),
                     null,
                     DiagnosticSeverity::ERROR,
                     'php'
diff --git a/src/utils.php b/src/utils.php
index 97e091d..af47a96 100644
--- a/src/utils.php
+++ b/src/utils.php
@@ -38,7 +38,7 @@ function pathToUri(string $filepath): string
 function uriToPath(string $uri)
 {
     $fragments = parse_url($uri);
-    if ($fragments === null || !isset($fragments['scheme']) || $fragments['scheme'] !== 'file') {
+    if ($fragments === false || !isset($fragments['scheme']) || $fragments['scheme'] !== 'file') {
         throw new InvalidArgumentException("Not a valid file URI: $uri");
     }
     $filepath = urldecode($fragments['path']);
diff --git a/tests/ClientHandlerTest.php b/tests/ClientHandlerTest.php
index 214b018..19114d9 100644
--- a/tests/ClientHandlerTest.php
+++ b/tests/ClientHandlerTest.php
@@ -5,7 +5,7 @@ namespace LanguageServer\Tests;
 
 use PHPUnit\Framework\TestCase;
 use LanguageServer\ClientHandler;
-use LanguageServer\Protocol\Message;
+use LanguageServer\Message;
 use AdvancedJsonRpc;
 use Sabre\Event\Loop;
 
diff --git a/tests/Diagnostics/InvalidThisUsageTest.php b/tests/Diagnostics/InvalidThisUsageTest.php
index b7e8196..566c1c0 100644
--- a/tests/Diagnostics/InvalidThisUsageTest.php
+++ b/tests/Diagnostics/InvalidThisUsageTest.php
@@ -9,7 +9,7 @@ use LanguageServer\{
     DefinitionResolver, TreeAnalyzer
 };
 use LanguageServer\Index\{Index};
-use LanguageServer\Protocol\{
+use LanguageServerProtocol\{
     Diagnostic, DiagnosticSeverity, Position, Range
 };
 use function LanguageServer\pathToUri;
diff --git a/tests/LanguageServerTest.php b/tests/LanguageServerTest.php
index 52963e6..10ca3f9 100644
--- a/tests/LanguageServerTest.php
+++ b/tests/LanguageServerTest.php
@@ -5,8 +5,8 @@ namespace LanguageServer\Tests;
 
 use PHPUnit\Framework\TestCase;
 use LanguageServer\LanguageServer;
-use LanguageServer\Protocol\{
-    Message,
+use LanguageServer\Message;
+use LanguageServerProtocol\{
     ClientCapabilities,
     TextDocumentSyncKind,
     MessageType,
diff --git a/tests/MockProtocolStream.php b/tests/MockProtocolStream.php
index b2a489d..9287053 100644
--- a/tests/MockProtocolStream.php
+++ b/tests/MockProtocolStream.php
@@ -4,7 +4,7 @@ declare(strict_types = 1);
 namespace LanguageServer\Tests;
 
 use LanguageServer\{ProtocolReader, ProtocolWriter};
-use LanguageServer\Protocol\Message;
+use LanguageServer\Message;
 use Sabre\Event\{Loop, Emitter, Promise};
 
 /**
diff --git a/tests/NodeVisitor/DefinitionCollectorTest.php b/tests/NodeVisitor/DefinitionCollectorTest.php
index a092b62..c27822c 100644
--- a/tests/NodeVisitor/DefinitionCollectorTest.php
+++ b/tests/NodeVisitor/DefinitionCollectorTest.php
@@ -35,7 +35,9 @@ class DefinitionCollectorTest extends TestCase
             'TestNamespace\\ChildClass',
             'TestNamespace\\Example',
             'TestNamespace\\Example->__construct()',
-            'TestNamespace\\Example->__destruct()'
+            'TestNamespace\\Example->__destruct()',
+            'TestNamespace\\InnerNamespace',
+            'TestNamespace\\InnerNamespace\\InnerClass',
         ], array_keys($defNodes));
 
         $this->assertInstanceOf(Node\ConstElement::class, $defNodes['TestNamespace\\TEST_CONST']);
@@ -53,6 +55,7 @@ class DefinitionCollectorTest extends TestCase
         $this->assertInstanceOf(Node\Statement\ClassDeclaration::class, $defNodes['TestNamespace\\Example']);
         $this->assertInstanceOf(Node\MethodDeclaration::class, $defNodes['TestNamespace\\Example->__construct()']);
         $this->assertInstanceOf(Node\MethodDeclaration::class, $defNodes['TestNamespace\\Example->__destruct()']);
+        $this->assertInstanceOf(Node\Statement\ClassDeclaration::class, $defNodes['TestNamespace\\InnerNamespace\\InnerClass']);
     }
 
     public function testDoesNotCollectReferences()
diff --git a/tests/PhpDocumentTest.php b/tests/PhpDocumentTest.php
index ae1b5cd..710e651 100644
--- a/tests/PhpDocumentTest.php
+++ b/tests/PhpDocumentTest.php
@@ -9,7 +9,7 @@ use LanguageServer\{
 use LanguageServer\Index\{
     Index
 };
-use LanguageServer\Protocol\{
+use LanguageServerProtocol\{
     Position
 };
 use Microsoft\PhpParser;
diff --git a/tests/ProtocolStreamReaderTest.php b/tests/ProtocolStreamReaderTest.php
index 69eea37..a0dcad5 100644
--- a/tests/ProtocolStreamReaderTest.php
+++ b/tests/ProtocolStreamReaderTest.php
@@ -5,7 +5,7 @@ namespace LanguageServer\Tests;
 
 use PHPUnit\Framework\TestCase;
 use LanguageServer\{LanguageServer, ProtocolStreamReader, ProtocolStreamWriter};
-use LanguageServer\Protocol\Message;
+use LanguageServer\Message;
 use AdvancedJsonRpc\{Request as RequestBody, Response as ResponseBody};
 use Sabre\Event\Loop;
 
diff --git a/tests/ProtocolStreamWriterTest.php b/tests/ProtocolStreamWriterTest.php
index b67bdcb..8ac94e7 100644
--- a/tests/ProtocolStreamWriterTest.php
+++ b/tests/ProtocolStreamWriterTest.php
@@ -5,7 +5,7 @@ namespace LanguageServer\Tests;
 
 use PHPUnit\Framework\TestCase;
 use LanguageServer\ProtocolStreamWriter;
-use LanguageServer\Protocol\Message;
+use LanguageServer\Message;
 use AdvancedJsonRpc\{Request as RequestBody};
 use Sabre\Event\Loop;
 
diff --git a/tests/Server/ServerTestCase.php b/tests/Server/ServerTestCase.php
index 45d949f..3331aef 100644
--- a/tests/Server/ServerTestCase.php
+++ b/tests/Server/ServerTestCase.php
@@ -10,7 +10,7 @@ use LanguageServer\{
 };
 use LanguageServer\Index\{ProjectIndex, DependenciesIndex, Index};
 use LanguageServer\ContentRetriever\FileSystemContentRetriever;
-use LanguageServer\Protocol\{Position, Location, Range};
+use LanguageServerProtocol\{Position, Location, Range};
 use function LanguageServer\pathToUri;
 
 abstract class ServerTestCase extends TestCase
@@ -107,7 +107,9 @@ abstract class ServerTestCase extends TestCase
             'TestNamespace\\whatever()'                    => new Location($referencesUri, new Range(new Position(21,  0), new Position(23,   1))),
             'TestNamespace\\Example'                       => new Location($symbolsUri,    new Range(new Position(101, 0), new Position(104,  1))),
             'TestNamespace\\Example::__construct'          => new Location($symbolsUri,    new Range(new Position(102, 4), new Position(102, 36))),
-            'TestNamespace\\Example::__destruct'           => new Location($symbolsUri,    new Range(new Position(103, 4), new Position(103, 35)))
+            'TestNamespace\\Example::__destruct'           => new Location($symbolsUri,    new Range(new Position(103, 4), new Position(103, 35))),
+            'TestNamespace\\InnerNamespace'                => new Location($symbolsUri,    new Range(new Position(106, 0), new Position(106, 39))),
+            'TestNamespace\\InnerNamespace\\InnerClass'    => new Location($symbolsUri,    new Range(new Position(108, 0), new Position(109,  1))),
         ];
 
         $this->referenceLocations = [
diff --git a/tests/Server/TextDocument/CompletionTest.php b/tests/Server/TextDocument/CompletionTest.php
index 2b4e9ff..516d3b4 100644
--- a/tests/Server/TextDocument/CompletionTest.php
+++ b/tests/Server/TextDocument/CompletionTest.php
@@ -10,7 +10,7 @@ use LanguageServer\{
 };
 use LanguageServer\Index\{Index, ProjectIndex, DependenciesIndex};
 use LanguageServer\ContentRetriever\FileSystemContentRetriever;
-use LanguageServer\Protocol\{
+use LanguageServerProtocol\{
     TextDocumentIdentifier,
     TextEdit,
     Range,
@@ -47,6 +47,9 @@ class CompletionTest extends TestCase
         $this->textDocument = new Server\TextDocument($this->loader, $definitionResolver, $client, $projectIndex);
     }
 
+    /**
+     * Tests completion at `$obj->t|`
+     */
     public function testPropertyAndMethodWithPrefix()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/property_with_prefix.php');
@@ -71,6 +74,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `public function a() { tes| }`
+     */
     public function testGlobalFunctionInsideNamespaceAndClass()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/inside_namespace_and_method.php');
@@ -92,6 +98,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `$obj->|`
+     */
     public function testPropertyAndMethodWithoutPrefix()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/property.php');
@@ -116,6 +125,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `$|` when variables are defined
+     */
     public function testVariable()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/variable.php');
@@ -148,6 +160,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `$p|` when variables are defined
+     */
     public function testVariableWithPrefix()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/variable_with_prefix.php');
@@ -170,6 +185,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `new|` when in a namespace and have used variables.
+     */
     public function testNewInNamespace()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/used_new.php');
@@ -218,27 +236,12 @@ class CompletionTest extends TestCase
                 null,
                 'TestClass'
             ),
-            new CompletionItem(
-                'ChildClass',
-                CompletionItemKind::CLASS_,
-                'TestNamespace',
-                null,
-                null,
-                null,
-                '\TestNamespace\ChildClass'
-            ),
-            new CompletionItem(
-                'Example',
-                CompletionItemKind::CLASS_,
-                'TestNamespace',
-                null,
-                null,
-                null,
-                '\TestNamespace\Example'
-            )
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `TestC|` with `use TestNamespace\TestClass`
+     */
     public function testUsedClass()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/used_class.php');
@@ -257,11 +260,74 @@ class CompletionTest extends TestCase
                     'laboris commodo ad commodo velit mollit qui non officia id. Nulla duis veniam' . "\n" .
                     'veniam officia deserunt et non dolore mollit ea quis eiusmod sit non. Occaecat' . "\n" .
                     'consequat sunt culpa exercitation pariatur id reprehenderit nisi incididunt Lorem' . "\n" .
-                    'sint. Officia culpa pariatur laborum nostrud cupidatat consequat mollit.'
+                    'sint. Officia culpa pariatur laborum nostrud cupidatat consequat mollit.',
+                null,
+                null,
+                'TestClass'
             )
         ], true), $items);
+
+        $this->assertCompletionsListDoesNotContainLabel('OtherClass', $items);
+        $this->assertCompletionsListDoesNotContainLabel('TestInterface', $items);
     }
 
+    /**
+     * Tests completion at `AliasNamespace\I|` with `use TestNamespace\InnerNamespace as AliasNamespace`
+     */
+    public function testUsedNamespaceWithPrefix()
+    {
+        $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/used_namespace.php');
+        $this->loader->open($completionUri, file_get_contents($completionUri));
+        $items = $this->textDocument->completion(
+            new TextDocumentIdentifier($completionUri),
+            new Position(8, 16)
+        )->wait();
+        $this->assertEquals(
+            new CompletionList([
+                new CompletionItem(
+                    'InnerClass',
+                    CompletionItemKind::CLASS_,
+                    'TestNamespace\\InnerNamespace',
+                    null,
+                    null,
+                    null,
+                    'AliasNamespace\\InnerClass'
+                )
+            ], true),
+            $items
+        );
+    }
+
+    /**
+     * Tests completion at `AliasNamespace\|` with `use TestNamespace\InnerNamespace as AliasNamespace`
+     */
+    public function testUsedNamespaceWithoutPrefix()
+    {
+        $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/used_namespace.php');
+        $this->loader->open($completionUri, file_get_contents($completionUri));
+        $items = $this->textDocument->completion(
+            new TextDocumentIdentifier($completionUri),
+            new Position(9, 15)
+        )->wait();
+        $this->assertEquals(
+            new CompletionList([
+                new CompletionItem(
+                    'InnerClass',
+                    CompletionItemKind::CLASS_,
+                    'TestNamespace\InnerNamespace',
+                    null,
+                    null,
+                    null,
+                    'AliasNamespace\InnerClass'
+                ),
+            ], true),
+            $items
+        );
+    }
+
+    /**
+     * Tests completion at `TestClass::$st|`
+     */
     public function testStaticPropertyWithPrefix()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/static_property_with_prefix.php');
@@ -283,6 +349,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `TestClass::|`
+     */
     public function testStaticWithoutPrefix()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/static.php');
@@ -316,6 +385,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `TestClass::st|`
+     */
     public function testStaticMethodWithPrefix()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/static_method_with_prefix.php');
@@ -325,21 +397,6 @@ class CompletionTest extends TestCase
             new Position(2, 13)
         )->wait();
         $this->assertCompletionsListSubset(new CompletionList([
-            new CompletionItem(
-                'TEST_CLASS_CONST',
-                CompletionItemKind::VARIABLE,
-                'int',
-                'Anim labore veniam consectetur laboris minim quis aute aute esse nulla ad.'
-            ),
-            new CompletionItem(
-                'staticTestProperty',
-                CompletionItemKind::PROPERTY,
-                '\TestClass[]',
-                'Lorem excepteur officia sit anim velit veniam enim.',
-                null,
-                null,
-                '$staticTestProperty'
-            ),
             new CompletionItem(
                 'staticTestMethod',
                 CompletionItemKind::METHOD,
@@ -349,6 +406,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `TestClass::TE` at the root level.
+     */
     public function testClassConstWithPrefix()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/class_const_with_prefix.php');
@@ -363,25 +423,13 @@ class CompletionTest extends TestCase
                 CompletionItemKind::VARIABLE,
                 'int',
                 'Anim labore veniam consectetur laboris minim quis aute aute esse nulla ad.'
-            ),
-            new CompletionItem(
-                'staticTestProperty',
-                CompletionItemKind::PROPERTY,
-                '\TestClass[]',
-                'Lorem excepteur officia sit anim velit veniam enim.',
-                null,
-                null,
-                '$staticTestProperty'
-            ),
-            new CompletionItem(
-                'staticTestMethod',
-                CompletionItemKind::METHOD,
-                'mixed',
-                'Do magna consequat veniam minim proident eiusmod incididunt aute proident.'
             )
         ], true), $items);
     }
 
+    /**
+     * Test completion at `\TestC|` in a namespace
+     */
     public function testFullyQualifiedClass()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/fully_qualified_class.php');
@@ -400,14 +448,18 @@ class CompletionTest extends TestCase
                 'laboris commodo ad commodo velit mollit qui non officia id. Nulla duis veniam' . "\n" .
                 'veniam officia deserunt et non dolore mollit ea quis eiusmod sit non. Occaecat' . "\n" .
                 'consequat sunt culpa exercitation pariatur id reprehenderit nisi incididunt Lorem' . "\n" .
-                'sint. Officia culpa pariatur laborum nostrud cupidatat consequat mollit.',
-                null,
-                null,
-                'TestClass'
+                'sint. Officia culpa pariatur laborum nostrud cupidatat consequat mollit.'
             )
         ], true), $items);
+        // Assert that all results are non-namespaced.
+        foreach ($items->items as $item) {
+            $this->assertSame($item->detail, null);
+        }
     }
 
+    /**
+     * Tests completion at `cl|` at root level
+     */
     public function testKeywords()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/keywords.php');
@@ -422,6 +474,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion in an empty file
+     */
     public function testHtmlWithoutPrefix()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/html.php');
@@ -444,6 +499,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion in `<|` when not within `<?php` tags
+     */
     public function testHtmlWontBeProposedWithoutCompletionContext()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/html_with_prefix.php');
@@ -456,6 +514,9 @@ class CompletionTest extends TestCase
         $this->assertEquals(new CompletionList([], true), $items);
     }
 
+    /**
+     * Tests completion in `<|` when not within `<?php` tags
+     */
     public function testHtmlWontBeProposedWithPrefixWithCompletionContext()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/html_with_prefix.php');
@@ -480,6 +541,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `<|` when not within `<?php` tags when triggered by trigger character.
+     */
     public function testHtmlPrefixShouldNotTriggerCompletion()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/html_no_completion.php');
@@ -492,6 +556,9 @@ class CompletionTest extends TestCase
         $this->assertEquals(new CompletionList([], true), $items);
     }
 
+    /**
+     * Tests completion at `<|` when not within `<?php` tags when triggered by user input.
+     */
     public function testHtmlPrefixShouldTriggerCompletionIfManuallyInvoked()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/html_no_completion.php');
@@ -515,6 +582,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `SomeNa|` when namespace `SomeNamespace` is defined
+     */
     public function testNamespace()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/namespace.php');
@@ -526,17 +596,15 @@ class CompletionTest extends TestCase
         $this->assertCompletionsListSubset(new CompletionList([
             new CompletionItem(
                 'SomeNamespace',
-                CompletionItemKind::MODULE,
-                null,
-                null,
-                null,
-                null,
-                'SomeNamespace'
+                CompletionItemKind::MODULE
             )
         ], true), $items);
     }
 
-    public function testBarePhp()
+    /**
+     * Tests completion at `echo $ab|` at the root level.
+     */
+    public function testBarePhpVariable()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/bare_php.php');
         $this->loader->open($completionUri, file_get_contents($completionUri));
@@ -776,6 +844,16 @@ class CompletionTest extends TestCase
         $this->assertEquals($subsetList->isIncomplete, $list->isIncomplete);
     }
 
+    private function assertCompletionsListDoesNotContainLabel(string $label, CompletionList $list)
+    {
+        foreach ($list->items as $item) {
+            $this->assertNotSame($label, $item->label, "Completion list should not contain $label.");
+        }
+    }
+
+    /**
+     * Tests completion for `$this->|`
+     */
     public function testThisWithoutPrefix()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/this.php');
@@ -812,6 +890,9 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `$this->m|`
+     */
     public function testThisWithPrefix()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/this_with_prefix.php');
@@ -821,18 +902,6 @@ class CompletionTest extends TestCase
             new Position(12, 16)
         )->wait();
         $this->assertEquals(new CompletionList([
-            new CompletionItem(
-                'testProperty',
-                CompletionItemKind::PROPERTY,
-                '\TestClass', // Type of the property
-                'Reprehenderit magna velit mollit ipsum do.'
-            ),
-            new CompletionItem(
-                'testMethod',
-                CompletionItemKind::METHOD,
-                '\TestClass', // Return type of the method
-                'Non culpa nostrud mollit esse sunt laboris in irure ullamco cupidatat amet.'
-            ),
             new CompletionItem(
                 'foo',
                 CompletionItemKind::PROPERTY,
@@ -856,10 +925,25 @@ class CompletionTest extends TestCase
                 CompletionItemKind::METHOD,
                 'mixed', // Return type of the method
                 null
-            )
+            ),
+            new CompletionItem(
+                'testProperty',
+                CompletionItemKind::PROPERTY,
+                '\TestClass', // Type of the property
+                'Reprehenderit magna velit mollit ipsum do.'
+            ),
+            new CompletionItem(
+                'testMethod',
+                CompletionItemKind::METHOD,
+                '\TestClass', // Return type of the method
+                'Non culpa nostrud mollit esse sunt laboris in irure ullamco cupidatat amet.'
+            ),
         ], true), $items);
     }
 
+    /**
+     * Tests completion at `$this->foo()->q|`
+     */
     public function testThisReturnValue()
     {
         $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/this_return_value.php');
@@ -869,11 +953,6 @@ class CompletionTest extends TestCase
             new Position(17, 23)
         )->wait();
         $this->assertEquals(new CompletionList([
-            new CompletionItem(
-                'foo',
-                CompletionItemKind::METHOD,
-                '$this' // Return type of the method
-            ),
             new CompletionItem(
                 'bar',
                 CompletionItemKind::METHOD,
@@ -883,7 +962,12 @@ class CompletionTest extends TestCase
                 'qux',
                 CompletionItemKind::METHOD,
                 'mixed' // Return type of the method
-            )
+            ),
+            new CompletionItem(
+                'foo',
+                CompletionItemKind::METHOD,
+                '$this' // Return type of the method
+            ),
         ], true), $items);
     }
 }
diff --git a/tests/Server/TextDocument/Definition/GlobalFallbackTest.php b/tests/Server/TextDocument/Definition/GlobalFallbackTest.php
index 4e45f9e..cca6d4d 100644
--- a/tests/Server/TextDocument/Definition/GlobalFallbackTest.php
+++ b/tests/Server/TextDocument/Definition/GlobalFallbackTest.php
@@ -10,7 +10,7 @@ use LanguageServer\{
 };
 use LanguageServer\Index\{Index, ProjectIndex, DependenciesIndex};
 use LanguageServer\ContentRetriever\FileSystemContentRetriever;
-use LanguageServer\Protocol\{TextDocumentIdentifier, Position, Range, Location};
+use LanguageServerProtocol\{TextDocumentIdentifier, Position, Range, Location};
 
 class GlobalFallbackTest extends ServerTestCase
 {
diff --git a/tests/Server/TextDocument/Definition/GlobalTest.php b/tests/Server/TextDocument/Definition/GlobalTest.php
index 2a80873..fdfb3b2 100644
--- a/tests/Server/TextDocument/Definition/GlobalTest.php
+++ b/tests/Server/TextDocument/Definition/GlobalTest.php
@@ -4,7 +4,7 @@ declare(strict_types = 1);
 namespace LanguageServer\Tests\Server\TextDocument\Definition;
 
 use LanguageServer\Tests\Server\ServerTestCase;
-use LanguageServer\Protocol\{TextDocumentIdentifier, Position, Location, Range};
+use LanguageServerProtocol\{TextDocumentIdentifier, Position, Location, Range};
 use function LanguageServer\pathToUri;
 
 class GlobalTest extends ServerTestCase
diff --git a/tests/Server/TextDocument/Definition/NamespacedTest.php b/tests/Server/TextDocument/Definition/NamespacedTest.php
index 395881b..0f9a582 100644
--- a/tests/Server/TextDocument/Definition/NamespacedTest.php
+++ b/tests/Server/TextDocument/Definition/NamespacedTest.php
@@ -3,7 +3,7 @@ declare(strict_types = 1);
 
 namespace LanguageServer\Tests\Server\TextDocument\Definition;
 
-use LanguageServer\Protocol\{TextDocumentIdentifier, Location};
+use LanguageServerProtocol\{TextDocumentIdentifier, Location};
 use function LanguageServer\pathToUri;
 
 class NamespacedTest extends GlobalTest
diff --git a/tests/Server/TextDocument/DidChangeTest.php b/tests/Server/TextDocument/DidChangeTest.php
index 4d26ed8..0f92ed7 100644
--- a/tests/Server/TextDocument/DidChangeTest.php
+++ b/tests/Server/TextDocument/DidChangeTest.php
@@ -10,7 +10,7 @@ use LanguageServer\{
 };
 use LanguageServer\ContentRetriever\FileSystemContentRetriever;
 use LanguageServer\Index\{Index, ProjectIndex, DependenciesIndex};
-use LanguageServer\Protocol\{
+use LanguageServerProtocol\{
     VersionedTextDocumentIdentifier,
     TextDocumentContentChangeEvent,
     Range,
diff --git a/tests/Server/TextDocument/DidCloseTest.php b/tests/Server/TextDocument/DidCloseTest.php
index 42daec5..22eb534 100644
--- a/tests/Server/TextDocument/DidCloseTest.php
+++ b/tests/Server/TextDocument/DidCloseTest.php
@@ -10,7 +10,7 @@ use LanguageServer\{
 };
 use LanguageServer\ContentRetriever\FileSystemContentRetriever;
 use LanguageServer\Index\{Index, ProjectIndex, DependenciesIndex};
-use LanguageServer\Protocol\{TextDocumentItem, TextDocumentIdentifier};
+use LanguageServerProtocol\{TextDocumentItem, TextDocumentIdentifier};
 
 class DidCloseTest extends TestCase
 {
diff --git a/tests/Server/TextDocument/DocumentSymbolTest.php b/tests/Server/TextDocument/DocumentSymbolTest.php
index 155e4a2..1267fd0 100644
--- a/tests/Server/TextDocument/DocumentSymbolTest.php
+++ b/tests/Server/TextDocument/DocumentSymbolTest.php
@@ -6,7 +6,7 @@ namespace LanguageServer\Tests\Server\TextDocument;
 use LanguageServer\Tests\Server\ServerTestCase;
 use LanguageServer\Tests\MockProtocolStream;
 use LanguageServer\{Server, LanguageClient, Project};
-use LanguageServer\Protocol\{TextDocumentIdentifier, SymbolInformation, SymbolKind, Position, Location, Range};
+use LanguageServerProtocol\{TextDocumentIdentifier, SymbolInformation, SymbolKind, Position, Location, Range};
 use function LanguageServer\pathToUri;
 
 class DocumentSymbolTest extends ServerTestCase
@@ -32,7 +32,9 @@ class DocumentSymbolTest extends ServerTestCase
             new SymbolInformation('ChildClass',         SymbolKind::CLASS_,      $this->getDefinitionLocation('TestNamespace\\ChildClass'),                    'TestNamespace'),
             new SymbolInformation('Example',            SymbolKind::CLASS_,      $this->getDefinitionLocation('TestNamespace\\Example'),                       'TestNamespace'),
             new SymbolInformation('__construct',        SymbolKind::CONSTRUCTOR, $this->getDefinitionLocation('TestNamespace\\Example::__construct'),          'TestNamespace\\Example'),
-            new SymbolInformation('__destruct',         SymbolKind::CONSTRUCTOR, $this->getDefinitionLocation('TestNamespace\\Example::__destruct'),           'TestNamespace\\Example')
+            new SymbolInformation('__destruct',         SymbolKind::CONSTRUCTOR, $this->getDefinitionLocation('TestNamespace\\Example::__destruct'),           'TestNamespace\\Example'),
+            new SymbolInformation('TestNamespace\\InnerNamespace', SymbolKind::NAMESPACE, $this->getDefinitionLocation('TestNamespace\\InnerNamespace'),       'TestNamespace'),
+            new SymbolInformation('InnerClass',         SymbolKind::CLASS_,      $this->getDefinitionLocation('TestNamespace\\InnerNamespace\\InnerClass'),    'TestNamespace\\InnerNamespace'),
         ], $result);
         // @codingStandardsIgnoreEnd
     }
diff --git a/tests/Server/TextDocument/HoverTest.php b/tests/Server/TextDocument/HoverTest.php
index 2ba49e1..42b69c8 100644
--- a/tests/Server/TextDocument/HoverTest.php
+++ b/tests/Server/TextDocument/HoverTest.php
@@ -6,7 +6,7 @@ namespace LanguageServer\Tests\Server\TextDocument;
 use LanguageServer\Tests\MockProtocolStream;
 use LanguageServer\Tests\Server\ServerTestCase;
 use LanguageServer\{Server, LanguageClient, Project};
-use LanguageServer\Protocol\{TextDocumentIdentifier, Position, Range, Hover, MarkedString};
+use LanguageServerProtocol\{TextDocumentIdentifier, Position, Range, Hover, MarkedString};
 use function LanguageServer\pathToUri;
 
 class HoverTest extends ServerTestCase
diff --git a/tests/Server/TextDocument/ParseErrorsTest.php b/tests/Server/TextDocument/ParseErrorsTest.php
index 4428523..09cdc98 100644
--- a/tests/Server/TextDocument/ParseErrorsTest.php
+++ b/tests/Server/TextDocument/ParseErrorsTest.php
@@ -10,7 +10,7 @@ use LanguageServer\{
 };
 use LanguageServer\Index\{Index, ProjectIndex, DependenciesIndex};
 use LanguageServer\ContentRetriever\FileSystemContentRetriever;
-use LanguageServer\Protocol\{TextDocumentItem, DiagnosticSeverity};
+use LanguageServerProtocol\{TextDocumentItem, DiagnosticSeverity};
 use Sabre\Event\Promise;
 use JsonMapper;
 
diff --git a/tests/Server/TextDocument/References/GlobalFallbackTest.php b/tests/Server/TextDocument/References/GlobalFallbackTest.php
index abfefce..b1cbdac 100644
--- a/tests/Server/TextDocument/References/GlobalFallbackTest.php
+++ b/tests/Server/TextDocument/References/GlobalFallbackTest.php
@@ -10,7 +10,7 @@ use LanguageServer\ContentRetriever\FileSystemContentRetriever;
 use LanguageServer\Index\{
     DependenciesIndex, Index, ProjectIndex
 };
-use LanguageServer\Protocol\{
+use LanguageServerProtocol\{
     Location, Position, Range, ReferenceContext, TextDocumentIdentifier
 };
 use LanguageServer\Tests\MockProtocolStream;
diff --git a/tests/Server/TextDocument/References/GlobalTest.php b/tests/Server/TextDocument/References/GlobalTest.php
index 105dfef..d2550c8 100644
--- a/tests/Server/TextDocument/References/GlobalTest.php
+++ b/tests/Server/TextDocument/References/GlobalTest.php
@@ -3,7 +3,7 @@ declare(strict_types = 1);
 
 namespace LanguageServer\Tests\Server\TextDocument\References;
 
-use LanguageServer\Protocol\{TextDocumentIdentifier, Position, ReferenceContext, Location, Range};
+use LanguageServerProtocol\{TextDocumentIdentifier, Position, ReferenceContext, Location, Range};
 use LanguageServer\Tests\Server\ServerTestCase;
 use function LanguageServer\pathToUri;
 
diff --git a/tests/Server/TextDocument/References/NamespacedTest.php b/tests/Server/TextDocument/References/NamespacedTest.php
index 1ee1ab4..b2bb9bb 100644
--- a/tests/Server/TextDocument/References/NamespacedTest.php
+++ b/tests/Server/TextDocument/References/NamespacedTest.php
@@ -3,7 +3,7 @@ declare(strict_types = 1);
 
 namespace LanguageServer\Tests\Server\TextDocument\References;
 
-use LanguageServer\Protocol\{TextDocumentIdentifier, Position, ReferenceContext, Location, Range};
+use LanguageServerProtocol\{TextDocumentIdentifier, Position, ReferenceContext, Location, Range};
 use function LanguageServer\pathToUri;
 
 class NamespacedTest extends GlobalTest
diff --git a/tests/Server/TextDocument/SignatureHelpTest.php b/tests/Server/TextDocument/SignatureHelpTest.php
index 2004aae..83dcb2c 100644
--- a/tests/Server/TextDocument/SignatureHelpTest.php
+++ b/tests/Server/TextDocument/SignatureHelpTest.php
@@ -10,7 +10,7 @@ use LanguageServer\{
 };
 use LanguageServer\Index\{Index, ProjectIndex, DependenciesIndex};
 use LanguageServer\ContentRetriever\FileSystemContentRetriever;
-use LanguageServer\Protocol\{
+use LanguageServerProtocol\{
     TextDocumentIdentifier,
     TextEdit,
     Range,
diff --git a/tests/Server/Workspace/DidChangeWatchedFilesTest.php b/tests/Server/Workspace/DidChangeWatchedFilesTest.php
index 1074c58..1f57acd 100644
--- a/tests/Server/Workspace/DidChangeWatchedFilesTest.php
+++ b/tests/Server/Workspace/DidChangeWatchedFilesTest.php
@@ -6,7 +6,8 @@ namespace LanguageServer\Tests\Server\Workspace;
 use LanguageServer\ContentRetriever\FileSystemContentRetriever;
 use LanguageServer\{DefinitionResolver, LanguageClient, PhpDocumentLoader, Server};
 use LanguageServer\Index\{DependenciesIndex, Index, ProjectIndex};
-use LanguageServer\Protocol\{FileChangeType, FileEvent, Message};
+use LanguageServerProtocol\{FileChangeType, FileEvent};
+use LanguageServer\Message;
 use LanguageServer\Tests\MockProtocolStream;
 use LanguageServer\Tests\Server\ServerTestCase;
 use LanguageServer\Server\Workspace;
diff --git a/tests/Server/Workspace/SymbolTest.php b/tests/Server/Workspace/SymbolTest.php
index 765841b..74fc92e 100644
--- a/tests/Server/Workspace/SymbolTest.php
+++ b/tests/Server/Workspace/SymbolTest.php
@@ -6,7 +6,7 @@ namespace LanguageServer\Tests\Server\Workspace;
 use LanguageServer\Tests\MockProtocolStream;
 use LanguageServer\Tests\Server\ServerTestCase;
 use LanguageServer\{Server, Client, LanguageClient, Project, PhpDocument};
-use LanguageServer\Protocol\{
+use LanguageServerProtocol\{
     TextDocumentItem,
     TextDocumentIdentifier,
     SymbolInformation,
@@ -30,7 +30,7 @@ class SymbolTest extends ServerTestCase
 
         // @codingStandardsIgnoreStart
         $this->assertEquals([
-            new SymbolInformation('TestNamespace',      SymbolKind::NAMESPACE, new Location($referencesUri, new Range(new Position(2, 0), new Position(2, 24))), ''),
+            new SymbolInformation('TestNamespace',          SymbolKind::NAMESPACE,   new Location($referencesUri, new Range(new Position(2, 0), new Position(2, 24))), ''),
             // Namespaced
             new SymbolInformation('TEST_CONST',             SymbolKind::CONSTANT,    $this->getDefinitionLocation('TestNamespace\\TEST_CONST'),                    'TestNamespace'),
             new SymbolInformation('TestClass',              SymbolKind::CLASS_,      $this->getDefinitionLocation('TestNamespace\\TestClass'),                     'TestNamespace'),
@@ -46,6 +46,8 @@ class SymbolTest extends ServerTestCase
             new SymbolInformation('Example',                SymbolKind::CLASS_,      $this->getDefinitionLocation('TestNamespace\\Example'),                       'TestNamespace'),
             new SymbolInformation('__construct',            SymbolKind::CONSTRUCTOR, $this->getDefinitionLocation('TestNamespace\\Example::__construct'),          'TestNamespace\\Example'),
             new SymbolInformation('__destruct',             SymbolKind::CONSTRUCTOR, $this->getDefinitionLocation('TestNamespace\\Example::__destruct'),           'TestNamespace\\Example'),
+            new SymbolInformation('TestNamespace\\InnerNamespace', SymbolKind::NAMESPACE, $this->getDefinitionLocation('TestNamespace\\InnerNamespace'),           'TestNamespace'),
+            new SymbolInformation('InnerClass',             SymbolKind::CLASS_,      $this->getDefinitionLocation('TestNamespace\\InnerNamespace\\InnerClass'),    'TestNamespace\\InnerNamespace'),
             new SymbolInformation('whatever',               SymbolKind::FUNCTION,    $this->getDefinitionLocation('TestNamespace\\whatever()'),                    'TestNamespace'),
             // Global
             new SymbolInformation('TEST_CONST',             SymbolKind::CONSTANT,    $this->getDefinitionLocation('TEST_CONST'),                                   ''),
diff --git a/tests/Validation/ValidationTest.php b/tests/Validation/ValidationTest.php
index 9057c9d..2c3efaf 100644
--- a/tests/Validation/ValidationTest.php
+++ b/tests/Validation/ValidationTest.php
@@ -13,7 +13,7 @@ use phpDocumentor\Reflection\DocBlock;
 use phpDocumentor\Reflection\DocBlockFactory;
 use PHPUnit\Framework\TestCase;
 use LanguageServer\ClientHandler;
-use LanguageServer\Protocol\Message;
+use LanguageServer\Message;
 use AdvancedJsonRpc;
 use RecursiveDirectoryIterator;
 use RecursiveIteratorIterator;
@@ -64,7 +64,7 @@ class ValidationTest extends TestCase
 
         try {
             $this->assertEquals($expectedValues['definitions'], $actualValues['definitions']);
-            $this->assertEquals((array)$expectedValues['references'], (array)$actualValues['references'], 'references don\'t match.');
+            $this->assertEquals((array)$expectedValues['references'], (array)$actualValues['references'], sprintf('references match in "%s"', $outputFile));
         } catch (\Throwable $e) {
             $outputFile = getExpectedValuesFile($testCaseFile);
             file_put_contents($outputFile, json_encode($actualValues, JSON_PRETTY_PRINT|JSON_UNESCAPED_SLASHES));
diff --git a/tests/Validation/cases/namespaces5.php b/tests/Validation/cases/namespaces5.php
index 85ee4b5..d4a37b2 100644
--- a/tests/Validation/cases/namespaces5.php
+++ b/tests/Validation/cases/namespaces5.php
@@ -1,3 +1,3 @@
 <?php
 namespace B;
-use LanguageServer\Protocol\{TextDocumentIdentifier, Position, ReferenceContext, Location, Range};
+use LanguageServerProtocol\{TextDocumentIdentifier, Position, ReferenceContext, Location, Range};
diff --git a/tests/Validation/cases/namespaces5.php.expected.json b/tests/Validation/cases/namespaces5.php.expected.json
index 7ad96f3..9a46a68 100644
--- a/tests/Validation/cases/namespaces5.php.expected.json
+++ b/tests/Validation/cases/namespaces5.php.expected.json
@@ -1,24 +1,21 @@
 {
     "references": {
-        "LanguageServer\\Protocol": [
+        "LanguageServerProtocol": [
             "./namespaces5.php"
         ],
-        "LanguageServer": [
+        "LanguageServerProtocol\\TextDocumentIdentifier": [
             "./namespaces5.php"
         ],
-        "LanguageServer\\Protocol\\TextDocumentIdentifier": [
+        "LanguageServerProtocol\\Position": [
             "./namespaces5.php"
         ],
-        "LanguageServer\\Protocol\\Position": [
+        "LanguageServerProtocol\\ReferenceContext": [
             "./namespaces5.php"
         ],
-        "LanguageServer\\Protocol\\ReferenceContext": [
+        "LanguageServerProtocol\\Location": [
             "./namespaces5.php"
         ],
-        "LanguageServer\\Protocol\\Location": [
-            "./namespaces5.php"
-        ],
-        "LanguageServer\\Protocol\\Range": [
+        "LanguageServerProtocol\\Range": [
             "./namespaces5.php"
         ]
     },