diff --git a/src/Composer/Plugin.php b/src/Composer/Plugin.php
index f5d8e5c..c8ae481 100644
--- a/src/Composer/Plugin.php
+++ b/src/Composer/Plugin.php
@@ -31,7 +31,7 @@ class Plugin implements PluginInterface, EventSubscriberInterface
     {
         $repoManager = $composer->getRepositoryManager();
         $repos = $repoManager->getRepositories();
-        $repoManager->prependRepository()
+        $repoManager->prependRepository();
         $this->io = $io;
     }
 
@@ -48,15 +48,14 @@ class Plugin implements PluginInterface, EventSubscriberInterface
 
 
     /**
-     * Emitted before composer solves dependencies
+     * Emitted before composer solves dependencies.
      *
      * @param InstallerEvent $event Event
-     * 
+     *
      * @return void
      */
     public function onDependencySolve(InstallerEvent $event): void
     {
-        var_dump($event);
+        \var_dump($event);
     }
-
 }
diff --git a/src/Context.php b/src/Context.php
index 6b5a244..b9f5929 100644
--- a/src/Context.php
+++ b/src/Context.php
@@ -30,10 +30,16 @@ class Context
      */
     public function insertBefore(Node $node, Node ...$nodes): void
     {
+        if (empty($nodes)) {
+            return;
+        }
         $subNode = $node->getAttribute('currentNode');
         $subNodeIndex = $node->getAttribute('currentNodeIndex');
         \array_splice($node->{$subNode}, $subNodeIndex, 0, $nodes);
-        $node->setAttribute('currentNodeIndex', $subNodeIndex+\count($nodes));
+        $skips = $node->getAttribute('skipNodes', []);
+        $skips []= $subNodeIndex+\count($nodes);
+        $node->setAttribute('skipNodes', $skips);
+        $node->setAttribute('currentNodeIndex', $subNodeIndex - 1);
     }
     /**
      * Insert nodes after node.
diff --git a/src/Plugin.php b/src/Plugin.php
index 2efcfcb..974be55 100644
--- a/src/Plugin.php
+++ b/src/Plugin.php
@@ -8,6 +8,7 @@ use PhpParser\Node\Arg;
 use PhpParser\Node\Expr;
 use PhpParser\Node\Expr\Assign;
 use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Expr\MethodCall;
 use PhpParser\Node\Expr\StaticCall;
 use PhpParser\Node\Expr\Variable;
 use PhpParser\Node\Name;
@@ -146,8 +147,8 @@ abstract class Plugin implements PluginInterface
     /**
      * Call function.
      *
-     * @param class-string|array{0: class-string, 1: string} $name          Function name
-     * @param Expr|Arg                                       ...$parameters Parameters
+     * @param class-string|array{0: class-string, 1: string}|callable-string $name          Function name
+     * @param Expr|Arg                                                       ...$parameters Parameters
      *
      * @return FuncCall|StaticCall
      */
@@ -168,6 +169,20 @@ abstract class Plugin implements PluginInterface
     {
         return self::call([static::class, $name], ...$parameters);
     }
+    /**
+     * Call method of object.
+     *
+     * @param Expr     $name          Object name
+     * @param string   $method        Method
+     * @param Expr|Arg ...$parameters Parameters
+     *
+     * @return MethodCall
+     */
+    public static function callMethod(Expr $name, string $method, ...$parameters): MethodCall
+    {
+        $parameters = \array_map(fn ($data) => $data instanceof Arg ? $data : new Arg($data), $parameters);
+        return new MethodCall($name, $method, $parameters);
+    }
     /**
      * Convert array, int or other literal to node.
      *
diff --git a/src/Plugin/Amp/YieldFromReplacer.php b/src/Plugin/Amp/YieldFromReplacer.php
deleted file mode 100644
index 327fb9b..0000000
--- a/src/Plugin/Amp/YieldFromReplacer.php
+++ /dev/null
@@ -1,28 +0,0 @@
-<?php
-
-namespace Spatie\Php7to5\NodeVisitors;
-
-use PhpParser\Node;
-use PhpParser\NodeVisitorAbstract;
-
-class YieldFromReplacer extends NodeVisitorAbstract
-{
-    /**
-     * @var array
-     */
-    protected $foreachYield;
-
-    /**
-     * {@inheritdoc}
-     */
-    public function leaveNode(Node $node)
-    {
-        if (!$node instanceof Node\Expr\YieldFrom) {
-            return;
-        }
-
-        $generator = $node->expr;
-
-        return new Node\Expr\Yield_($generator);
-    }
-}
diff --git a/src/Plugin/NameResolver.php b/src/Plugin/NameResolver.php
new file mode 100644
index 0000000..dd16e75
--- /dev/null
+++ b/src/Plugin/NameResolver.php
@@ -0,0 +1,241 @@
+<?php declare(strict_types=1);
+
+namespace Phabel\Plugin;
+
+use Phabel\Plugin;
+use PhpParser\ErrorHandler;
+use PhpParser\NameContext;
+use PhpParser\Node;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Name;
+use PhpParser\Node\Name\FullyQualified;
+use PhpParser\Node\Stmt;
+
+class NameResolver extends Plugin
+{
+    /** @var NameContext Naming context */
+    protected $nameContext;
+
+    /**
+     * Constructs a name resolution visitor.
+     *
+     * Options:
+     *  * preserveOriginalNames (default false): An "originalName" attribute will be added to
+     *    all name nodes that underwent resolution.
+     *  * replaceNodes (default true): Resolved names are replaced in-place. Otherwise, a
+     *    resolvedName attribute is added. (Names that cannot be statically resolved receive a
+     *    namespacedName attribute, as usual.)
+     *
+     * @param ErrorHandler|null $errorHandler Error handler
+     * @param array $options Options
+     */
+    public function __construct(ErrorHandler $errorHandler = null, array $options = [])
+    {
+        $this->nameContext = new NameContext($errorHandler ?? new ErrorHandler\Throwing);
+    }
+
+    /**
+     * Get name resolution context.
+     *
+     * @return NameContext
+     */
+    public function getNameContext(): NameContext
+    {
+        return $this->nameContext;
+    }
+
+    public function beforeTraverse(array $nodes)
+    {
+        $this->nameContext->startNamespace();
+        return null;
+    }
+
+    public function enterNode(Node $node)
+    {
+        if ($node instanceof Stmt\Namespace_) {
+            $this->nameContext->startNamespace($node->name);
+        } elseif ($node instanceof Stmt\Use_) {
+            foreach ($node->uses as $use) {
+                $this->addAlias($use, $node->type, null);
+            }
+        } elseif ($node instanceof Stmt\GroupUse) {
+            foreach ($node->uses as $use) {
+                $this->addAlias($use, $node->type, $node->prefix);
+            }
+        } elseif ($node instanceof Stmt\Class_) {
+            if (null !== $node->extends) {
+                $node->extends = $this->resolveClassName($node->extends);
+            }
+
+            foreach ($node->implements as &$interface) {
+                $interface = $this->resolveClassName($interface);
+            }
+
+            if (null !== $node->name) {
+                $this->addNamespacedName($node);
+            }
+        } elseif ($node instanceof Stmt\Interface_) {
+            foreach ($node->extends as &$interface) {
+                $interface = $this->resolveClassName($interface);
+            }
+
+            $this->addNamespacedName($node);
+        } elseif ($node instanceof Stmt\Trait_) {
+            $this->addNamespacedName($node);
+        } elseif ($node instanceof Stmt\Function_) {
+            $this->addNamespacedName($node);
+            $this->resolveSignature($node);
+        } elseif ($node instanceof Stmt\ClassMethod
+                  || $node instanceof Expr\Closure
+                  || $node instanceof Expr\ArrowFunction
+        ) {
+            $this->resolveSignature($node);
+        } elseif ($node instanceof Stmt\Property) {
+            if (null !== $node->type) {
+                $node->type = $this->resolveType($node->type);
+            }
+        } elseif ($node instanceof Stmt\Const_) {
+            foreach ($node->consts as $const) {
+                $this->addNamespacedName($const);
+            }
+        } elseif ($node instanceof Expr\StaticCall
+                  || $node instanceof Expr\StaticPropertyFetch
+                  || $node instanceof Expr\ClassConstFetch
+                  || $node instanceof Expr\New_
+                  || $node instanceof Expr\Instanceof_
+        ) {
+            if ($node->class instanceof Name) {
+                $node->class = $this->resolveClassName($node->class);
+            }
+        } elseif ($node instanceof Stmt\Catch_) {
+            foreach ($node->types as &$type) {
+                $type = $this->resolveClassName($type);
+            }
+        } elseif ($node instanceof Expr\FuncCall) {
+            if ($node->name instanceof Name) {
+                $node->name = $this->resolveName($node->name, Stmt\Use_::TYPE_FUNCTION);
+            }
+        } elseif ($node instanceof Expr\ConstFetch) {
+            $node->name = $this->resolveName($node->name, Stmt\Use_::TYPE_CONSTANT);
+        } elseif ($node instanceof Stmt\TraitUse) {
+            foreach ($node->traits as &$trait) {
+                $trait = $this->resolveClassName($trait);
+            }
+
+            foreach ($node->adaptations as $adaptation) {
+                if (null !== $adaptation->trait) {
+                    $adaptation->trait = $this->resolveClassName($adaptation->trait);
+                }
+
+                if ($adaptation instanceof Stmt\TraitUseAdaptation\Precedence) {
+                    foreach ($adaptation->insteadof as &$insteadof) {
+                        $insteadof = $this->resolveClassName($insteadof);
+                    }
+                }
+            }
+        }
+
+        return null;
+    }
+
+    private function addAlias(Stmt\UseUse $use, $type, Name $prefix = null)
+    {
+        // Add prefix for group uses
+        $name = $prefix ? Name::concat($prefix, $use->name) : $use->name;
+        // Type is determined either by individual element or whole use declaration
+        $type |= $use->type;
+
+        $this->nameContext->addAlias(
+            $name,
+            (string) $use->getAlias(),
+            $type,
+            $use->getAttributes()
+        );
+    }
+
+    /** @param Stmt\Function_|Stmt\ClassMethod|Expr\Closure $node */
+    private function resolveSignature($node)
+    {
+        foreach ($node->params as $param) {
+            $param->type = $this->resolveType($param->type);
+        }
+        $node->returnType = $this->resolveType($node->returnType);
+    }
+
+    private function resolveType($node)
+    {
+        if ($node instanceof Name) {
+            return $this->resolveClassName($node);
+        }
+        if ($node instanceof Node\NullableType) {
+            $node->type = $this->resolveType($node->type);
+            return $node;
+        }
+        if ($node instanceof Node\UnionType) {
+            foreach ($node->types as &$type) {
+                $type = $this->resolveType($type);
+            }
+            return $node;
+        }
+        return $node;
+    }
+
+    /**
+     * Resolve name, according to name resolver options.
+     *
+     * @param Name $name Function or constant name to resolve
+     * @param int  $type One of Stmt\Use_::TYPE_*
+     *
+     * @return Name Resolved name, or original name with attribute
+     */
+    protected function resolveName(Name $name, int $type): Name
+    {
+        if (!$this->replaceNodes) {
+            $resolvedName = $this->nameContext->getResolvedName($name, $type);
+            if (null !== $resolvedName) {
+                $name->setAttribute('resolvedName', $resolvedName);
+            } else {
+                $name->setAttribute('namespacedName', FullyQualified::concat(
+                    $this->nameContext->getNamespace(),
+                    $name,
+                    $name->getAttributes()
+                ));
+            }
+            return $name;
+        }
+
+        if ($this->preserveOriginalNames) {
+            // Save the original name
+            $originalName = $name;
+            $name = clone $originalName;
+            $name->setAttribute('originalName', $originalName);
+        }
+
+        $resolvedName = $this->nameContext->getResolvedName($name, $type);
+        if (null !== $resolvedName) {
+            return $resolvedName;
+        }
+
+        // unqualified names inside a namespace cannot be resolved at compile-time
+        // add the namespaced version of the name as an attribute
+        $name->setAttribute('namespacedName', FullyQualified::concat(
+            $this->nameContext->getNamespace(),
+            $name,
+            $name->getAttributes()
+        ));
+        return $name;
+    }
+
+    protected function resolveClassName(Name $name)
+    {
+        return $this->resolveName($name, Stmt\Use_::TYPE_NORMAL);
+    }
+
+    protected function addNamespacedName(Node $node)
+    {
+        $node->namespacedName = Name::concat(
+            $this->nameContext->getNamespace(),
+            (string) $node->name
+        );
+    }
+}
diff --git a/src/Plugin/StringConcatOptimizer.php b/src/Plugin/StringConcatOptimizer.php
new file mode 100644
index 0000000..b298650
--- /dev/null
+++ b/src/Plugin/StringConcatOptimizer.php
@@ -0,0 +1,58 @@
+<?php
+
+namespace Phabel\Plugin;
+
+use Phabel\Context;
+use Phabel\Plugin;
+use PhpParser\Node;
+use PhpParser\Node\Expr\BinaryOp\Concat;
+use PhpParser\Node\Scalar\String_;
+use SplQueue;
+
+/**
+ * Optimizes concatenation of multiple strings.
+ */
+class StringConcatOptimizer extends Plugin
+{
+    private function enqueue(Concat $concat, SplQueue $queue)
+    {
+        if ($concat->left instanceof Concat) {
+            $this->enqueue($concat->left, $queue);
+        } else {
+            $queue->enqueue($concat->left);
+        }
+        if ($concat->right instanceof Concat) {
+            $this->enqueue($concat->right, $queue);
+        } else {
+            $queue->enqueue($concat->right);
+        }
+    }
+    public function enter(Concat $concat, Context $ctx): ?Node
+    {
+        if ($ctx->parents->top() instanceof Concat) {
+            return;
+        }
+        $concatQueue = new SplQueue;
+        $this->enqueue($concat, $concatQueue);
+        $newQueue = new SplQueue;
+        $prevNode = $concatQueue->dequeue();
+        while ($node = $concatQueue->dequeue()) {
+            if ($node instanceof String_ && $prevNode instanceof String_) {
+                $prevNode = new String_($prevNode->value.$node->value);
+            } else {
+                $newQueue->enqueue($prevNode);
+                $prevNode = $node;
+            }
+        }
+        $newQueue->enqueue($prevNode);
+
+        if ($newQueue->count() === 1) {
+            return $newQueue->dequeue();
+        }
+        $concat = new Concat($newQueue->dequeue(), $newQueue->dequeue());
+        while ($node = $newQueue->dequeue()) {
+            $concat = new Concat($concat, $newQueue->dequeue());
+        }
+        return $concat;
+    }
+}
diff --git a/src/Plugin/TypeHintStripper.php b/src/Plugin/TypeHintStripper.php
index 7c4261a..5675762 100644
--- a/src/Plugin/TypeHintStripper.php
+++ b/src/Plugin/TypeHintStripper.php
@@ -4,7 +4,10 @@ namespace Phabel\Plugin;
 
 use Phabel\Context;
 use Phabel\Plugin;
+use Phabel\Target\Php74\ArrowClosure;
 use PhpParser\Node;
+use PhpParser\Node\Arg;
+use PhpParser\Node\Expr;
 use PhpParser\Node\Expr\ArrowFunction;
 use PhpParser\Node\Expr\Assign;
 use PhpParser\Node\Expr\AssignRef;
@@ -27,6 +30,7 @@ use PhpParser\Node\Scalar\LNumber;
 use PhpParser\Node\Scalar\MagicConst\Function_ as MagicConstFunction_;
 use PhpParser\Node\Scalar\MagicConst\Method;
 use PhpParser\Node\Scalar\String_;
+use PhpParser\Node\Stmt\ClassLike;
 use PhpParser\Node\Stmt\ClassMethod;
 use PhpParser\Node\Stmt\Foreach_;
 use PhpParser\Node\Stmt\If_;
@@ -42,27 +46,53 @@ use SplStack;
  */
 class TypeHintStripper extends Plugin
 {
+    private const IGNORE_RETURN = 0;
+    private const VOID_RETURN = 1;
+    private const TYPE_RETURN = 2;
+    /**
+     * Stack.
+     *
+     * @template T as array{0: self::IGNORE_RETURN|self::VOID_RETURN}|array{0: self::TYPE_RETURN, 1: Node, 2: bool, 3: bool, 4: Node, 5: BooleanNot}
+     *
+     * @var SplStack<T>
+     */
     private SplStack $stack;
+    /**
+     * Constructor.
+     */
     public function __construct()
     {
-        $this->stack = $stack;
+        $this->stack = new SplStack;
     }
+    /**
+     * Convert a function to a closure.
+     */
     private function toClosure(FunctionLike &$func): void
     {
         if ($func instanceof ArrowFunction) {
-            $nodes = [];
-            foreach ($func->getSubNodeNames() as $node) {
-                $nodes[$node] = $func->{$nodes};
-            }
-            $func = new Closure($nodes, $func->getAttributes());
+            $func = ArrowClosure::enterClosure($func);
         }
     }
+    /**
+     * Generate.
+     *
+     * @param Variable            $var          Variable to check
+     * @param (Name|Identifier)[] $types        Types to check
+     * @param boolean             $fromNullable Whether this type is nullable
+     *
+     * @return array{0: bool, 1: Node, 2: BooleanNot} Whether the polyfilled gettype should be used, the error message, the condition
+     */
     private function generateConditions(Variable $var, array $types, bool $fromNullable = false): array
     {
+        /** @var bool Whether no explicit classes were referenced */
         $noOopTypes = true;
+        /** @var string[] */
         $typeNames = [];
+        /** @var Expr[] */
+        $conditions = [];
+        /** @var string Last string type name */
         $stringType = '';
-        foreach ($types as &$type) {
+        foreach ($types as $type) {
             $typeNames []= $type->toString();
 
             if ($type instanceof Identifier) {
@@ -80,11 +110,11 @@ class TypeHintStripper extends Plugin
                         $stringType = new String_($typeName === 'callable' ?
                             $typeName :
                             ($typeName === 'object' ? 'an object' : "of type $typeName"));
-                        $type = Plugin::call("is_$typeName", $var);
+                        $conditions []= Plugin::call("is_$typeName", $var);
                         break;
                     case 'iterable':
                         $stringType = new String_('iterable');
-                        $type = new BooleanOr(
+                        $conditions []= new BooleanOr(
                             Plugin::call("is_array", $var),
                             new Instanceof_($var, new Name(\Traversable::class))
                         );
@@ -92,24 +122,29 @@ class TypeHintStripper extends Plugin
                     default:
                         $noOopTypes = false;
                         $stringType = $type->isSpecialClassName() ?
-                            new Concat(new String_("an instance of "), new ClassConstFetch($type, new Identifier('class'))) :
+                            new Concat(new String_("an instance of "), new ClassConstFetch(new Name($typeName), new Identifier('class'))) :
                             new String_("an instance of ".$type->toString());
-                        $type = new Instanceof_($var, $type);
+                        $conditions []= new Instanceof_($var, new Name($typeName));
                 }
             } else {
                 $noOopTypes = false;
                 $stringType = new String_("an instance of ".$type->toString());
-                if ($type->toString() === 'Stringable' || $type->toString() === \Stringable::class) {
-                    $type = Plugin::callPoly("is_stringable", $var);
-                } else {
-                    $type = new Instanceof_($var, $type);
-                }
+                $conditions []= new Instanceof_($var, $type);
             }
         }
         if (\count($typeNames) > 1) {
             $stringType = new String_(\implode("|", $typeNames));
         }
-        $condition = new BooleanNot(\count($types) === 1 ? $types[0] : \array_reduce($types, fn (Node $a, Node $b): BooleanOr => new BooleanOr($a, $b)));
+        if ($fromNullable) {
+            $stringType = new Concat($stringType, new String_(' or null'));
+            $conditions []= Plugin::call("is_null", $var);
+        }
+        $initial = \array_shift($conditions);
+        $condition = new BooleanNot(
+            empty($conditions)
+            ? $initial
+            : \array_reduce($conditions, fn (Expr $a, Expr $b): BooleanOr => new BooleanOr($a, $b), $initial)
+        );
         return [$noOopTypes, $stringType, $condition];
     }
     /**
@@ -118,12 +153,12 @@ class TypeHintStripper extends Plugin
      * @param Variable                                    $var  Variable
      * @param null|Identifier|Name|NullableType|UnionType $type Type
      *
-     * @return array{0: bool, 1: Node, 2: BooleanNot} Conditions for if
+     * @return null|array{0: bool, 1: Node, 2: BooleanNot} Whether the polyfilled gettype should be used, the error message, the condition
      */
-    private function strip(Variable $var, ?Node $type): array
+    private function strip(Variable $var, ?Node $type): ?array
     {
         if (!$type) {
-            return [];
+            return null;
         }
         if ($type instanceof UnionType && $this->getConfig('union', false)) {
             return $this->generateConditions($var, $type->types);
@@ -142,9 +177,9 @@ class TypeHintStripper extends Plugin
      *
      * @param FunctionLike $func Function
      *
-     * @return void
+     * @return ?FunctionLike
      */
-    public function enterFunction(FunctionLike $func, Context $ctx): void
+    public function enterFunction(FunctionLike $func, Context $ctx): ?FunctionLike
     {
         $functionName = new Method();
         if ($func instanceof ClassMethod) {
@@ -169,9 +204,9 @@ class TypeHintStripper extends Plugin
             $start = new Concat($start, new String_(", "));
             $start = new Concat($start, $noOop ? self::call('gettype', $param->var) : self::callPoly('gettype', $param->var));
             $start = new Concat($start, new String_(" given, called in "));
-            $start = new Concat($start, self::callPoly('trace', 0));
+            $start = new Concat($start, self::callPoly('trace', new LNumber(0)));
 
-            $if = new If_($condition, [new Throw_(new New_(new FullyQualified(\TypeError::class), [$start]))]);
+            $if = new If_($condition, [new Throw_(new New_(new FullyQualified(\TypeError::class), [new Arg($start)]))]);
             if ($param->variadic) {
                 $stmts []= new Foreach_($param->var, new Variable('phabelVariadic'), ['keyVar' => new Variable('phabelVariadicIndex'), 'stmts' => [$if]]);
             } else {
@@ -180,34 +215,34 @@ class TypeHintStripper extends Plugin
         }
         if ($stmts) {
             $this->toClosure($func);
-            $func->stmts = \array_merge($stmts, $func->getStmts());
+            $func->stmts = \array_merge($stmts, $func->getStmts() ?? []);
         }
 
         if ($this->getConfig('void', false) && $func->getReturnType() instanceof Identifier && $func->getReturnType()->toLowerString() === 'void') {
             $this->toClosure($func);
-            $this->stack->push([true]);
+            $this->stack->push([self::VOID_RETURN]);
         }
         $var = new Variable('phabelReturn');
-        if (!$condition = $this->strip($var, $func->getReturnType(), false)) {
-            $this->stack->push([null]);
-            return;
+        if (!$condition = $this->strip($var, $func->getReturnType())) {
+            $this->stack->push([self::IGNORE_RETURN]);
+            return null;
         }
         $this->toClosure($func);
-        $this->stack->push([false, $functionName, $func->returnsByRef(), ...$condition]);
+        $this->stack->push([self::TYPE_RETURN, $functionName, $func->returnsByRef(), ...$condition]);
         return $func;
     }
     public function enterReturn(Return_ $return, Context $ctx): ?Node
     {
         $current = $this->stack->top();
-        if ($current[0] === null) {
-            return;
+        if ($current[0] === self::IGNORE_RETURN) {
+            return null;
         }
-        if ($current[0] === true) {
+        if ($current[0] === self::VOID_RETURN) {
             if ($return->expr !== null) {
                 // This should be a transpilation error, wait for better stack traces before throwing here
                 return new Throw_(new New_(new FullyQualified(\ParseError::class), [new String_("A void function must not return a value")]));
             }
-            return;
+            return null;
         }
         [, $functionName, $byRef, $noOop, $string, $condition] = $current;
 
@@ -223,17 +258,31 @@ class TypeHintStripper extends Plugin
         $start = new Concat($start, new String_(" returned in "));
         $start = new Concat($start, self::callPoly('trace', 0));
 
-        $if = new If_($condition, [new Throw_(new New_(new FullyQualified(\TypeError::class), [$start]))]);
+        $if = new If_($condition, [new Throw_(new New_(new FullyQualified(\TypeError::class), [new Arg($start)]))]);
 
         $return->expr = $var;
 
         $ctx->insertBefore($ctx->parents->top(), $assign, $if);
     }
-    public static function trace($index): string
+    /**
+     * Get trace string for errors.
+     *
+     * @param int $index Index
+     *
+     * @return string
+     */
+    public static function trace($index)
     {
         $trace = \debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2)[$index];
         return ($trace['file'] ?? '').' on line '.($trace['line'] ?? '');
     }
+    /**
+     * Get type string or object.
+     *
+     * @param mixed $object Object
+     *
+     * @return string
+     */
     public static function gettype($object)
     {
         if (\is_object($object)) {
@@ -243,10 +292,11 @@ class TypeHintStripper extends Plugin
         return \gettype($object);
     }
 
-    public static function is_stringable($string): bool
-    {
-        return is_string($string) || (is_object($string) && method_exists($string, '__toString'));
-    }
+    /**
+     * Runwithafter.
+     *
+     * @return array
+     */
     public static function runWithAfter(): array
     {
         return [StringConcatOptimizer::class];
diff --git a/src/RootNode.php b/src/RootNode.php
index fed6bc7..f1e3ac3 100644
--- a/src/RootNode.php
+++ b/src/RootNode.php
@@ -6,12 +6,12 @@ use PhpParser\Node;
 use PhpParser\NodeAbstract;
 
 /**
- * Root node
+ * Root node.
  */
 class RootNode extends NodeAbstract
 {
     /**
-     * Children
+     * Children.
      *
      * @var Node[]
      */
@@ -29,4 +29,4 @@ class RootNode extends NodeAbstract
     {
         return 'rootNode';
     }
-}
\ No newline at end of file
+}
diff --git a/src/Target/Php70/ThrowableReplacer.php b/src/Target/Php70/ThrowableReplacer.php
index db56722..b7dd39f 100644
--- a/src/Target/Php70/ThrowableReplacer.php
+++ b/src/Target/Php70/ThrowableReplacer.php
@@ -4,6 +4,7 @@ namespace Phabel\Target\Php70;
 
 use Phabel\Plugin;
 use Phabel\Plugin\TypeHintStripper;
+use Phabel\Target\Php71\MultipleCatchReplacer;
 use PhpParser\Node;
 use PhpParser\Node\Expr\BinaryOp\BooleanOr;
 use PhpParser\Node\Expr\Instanceof_;
@@ -25,7 +26,6 @@ class ThrowableReplacer extends Plugin
      */
     private function isThrowable(string $type): bool
     {
-        // Make this less ugly when we implement a namespace context
         return $type === \Throwable::class || $type === 'Throwable';
     }
     /**
@@ -86,7 +86,8 @@ class ThrowableReplacer extends Plugin
                     \Throwable::class,
                     'Throwable'
                 ]
-            ]
+            ],
+            MultipleCatchReplacer::class => []
         ];
     }
 }
diff --git a/src/Target/Php70/YieldFromReplacer.php b/src/Target/Php70/YieldFromReplacer.php
new file mode 100644
index 0000000..d59e826
--- /dev/null
+++ b/src/Target/Php70/YieldFromReplacer.php
@@ -0,0 +1,42 @@
+<?php
+
+namespace Phabel\Target\Php70;
+
+use Phabel\Context;
+use Phabel\Plugin;
+use PhpParser\Node;
+use PhpParser\Node\Expr\Assign;
+use PhpParser\Node\Expr\Instanceof_;
+use PhpParser\Node\Expr\MethodCall;
+use PhpParser\Node\Expr\Variable;
+use PhpParser\Node\Expr\YieldFrom;
+use PhpParser\Node\Identifier;
+use PhpParser\Node\Name\FullyQualified;
+use PhpParser\Node\Stmt\If_;
+use PhpParser\Node\Stmt\While_;
+
+class YieldFromReplacer extends Plugin
+{
+    private string $phabelVar = '';
+    private int $phabelCount = 0;
+    public function shouldRunFile(string $file): bool
+    {
+        $this->phabelVar = 'phabelGeneratorYieldFrom'.\hash('sha256', $file);
+        return parent::shouldRunFile($file);
+    }
+    public function enterNode(YieldFrom $node, Context $ctx)
+    {
+        $var = new Variable($this->phabelVar.($this->phabelCount++));
+        $assign = new Assign($var, $node->expr);
+        $ifInstanceof = new If_(new Instanceof_(Plugin::callMethod($var, 'valid'), new FullyQualified(\YieldReturnValue::class)), ['stmts' => [new Assign()]]);
+        $while = new While_(new MethodCall($var, new Identifier('valid')));
+        foreach ($ctx->parents as $node) {
+            if ($node->hasAttribute('currentNodeIndex')) {
+                $ctx->insertBefore($node, $node->expr);
+            }
+        }
+        $generator = $node->expr;
+
+        return new Node\Expr\Yield_($generator);
+    }
+}
diff --git a/src/Target/Php71/MultipleCatchReplacer.php b/src/Target/Php71/MultipleCatchReplacer.php
index d134483..aa3b131 100644
--- a/src/Target/Php71/MultipleCatchReplacer.php
+++ b/src/Target/Php71/MultipleCatchReplacer.php
@@ -35,15 +35,4 @@ class MultipleCatchReplacer extends Plugin
         }
         $node->catches = $catches;
     }
-    /**
-     * Extends throwable replacer.
-     *
-     * @return string
-     *
-     * @psalm-return class-string
-     */
-    public static function runWithBefore(): string
-    {
-        return [ThrowableReplacer::class];
-    }
 }
diff --git a/src/Target/Php71/NullableTypeRemover.php b/src/Target/Php71/NullableType.php
similarity index 81%
rename from src/Target/Php71/NullableTypeRemover.php
rename to src/Target/Php71/NullableType.php
index fe68fc9..791921c 100644
--- a/src/Target/Php71/NullableTypeRemover.php
+++ b/src/Target/Php71/NullableType.php
@@ -5,7 +5,7 @@ namespace Spatie\Php7to5\NodeVisitors;
 use Phabel\Plugin;
 use Phabel\Plugin\TypeHintStripper;
 
-class NullableTypeRemover extends Plugin
+class NullableType extends Plugin
 {
     /**
      * Remove nullable typehint.
@@ -16,7 +16,7 @@ class NullableTypeRemover extends Plugin
     {
         return [
             TypeHintStripper::class => [
-                'nulable' => true
+                'nullable' => true
             ]
         ];
     }
diff --git a/src/Target/Php71/VoidReturnType.php b/src/Target/Php71/VoidReturnType.php
new file mode 100644
index 0000000..b26fae1
--- /dev/null
+++ b/src/Target/Php71/VoidReturnType.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Spatie\Php7to5\NodeVisitors;
+
+use Phabel\Plugin;
+use Phabel\Plugin\TypeHintStripper;
+
+class VoidReturnType extends Plugin
+{
+    /**
+     * Remove void return typehint.
+     *
+     * @return array
+     */
+    public static function runAfter(): array
+    {
+        return [
+            TypeHintStripper::class => [
+                'void' => true
+            ]
+        ];
+    }
+}
diff --git a/src/Target/Php74/ArrowClosure.php b/src/Target/Php74/ArrowClosure.php
new file mode 100644
index 0000000..ad53e32
--- /dev/null
+++ b/src/Target/Php74/ArrowClosure.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace Phabel\Target\Php74;
+
+use PhpParser\Node\Expr\ArrowFunction;
+use PhpParser\Node\Expr\Closure;
+
+/**
+ * Turn an arrow function into a closure.
+ */
+class ArrowClosure
+{
+    /**
+     * Enter arrow function.
+     *
+     * @param ArrowFunction $func Arrow function
+     *
+     * @return Closure
+     */
+    public static function enterClosure(ArrowFunction $func): Closure
+    {
+        $nodes = [];
+        foreach ($func->getSubNodeNames() as $node) {
+            $nodes[$node] = $func->{$node};
+        }
+        return new Closure($nodes, $func->getAttributes());
+    }
+}
diff --git a/src/Target/Php80.php b/src/Target/Php80.php
new file mode 100644
index 0000000..eec270e
--- /dev/null
+++ b/src/Target/Php80.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace Phabel\Target;
+
+use Phabel\Plugin;
+use Phabel\UnionTypeStripper;
+
+/**
+ * Makes changes necessary to polyfill PHP 8.0 and run on PHP 7.4 and below.
+ *
+ * @author Daniil Gentili <daniil@daniil.it>
+ * @license MIT
+ */
+class Php80 extends Plugin
+{
+    public static function composerRequires(): array
+    {
+        return ['symfony/polyfill-php80' => '*'];
+    }
+
+    public static function runWithAfter(): array
+    {
+        return [
+            UnionTypeStripper::class,
+        ];
+    }
+}
diff --git a/src/Target/Php80/UnionTypeStripper.php b/src/Target/Php80/UnionTypeStripper.php
new file mode 100644
index 0000000..93aeef6
--- /dev/null
+++ b/src/Target/Php80/UnionTypeStripper.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace Phabel;
+
+use Phabel\Plugin\TypeHintStripper;
+
+/**
+ * Strip union types, polyfilling type checks.
+ */
+class UnionTypeStripper extends Plugin
+{
+    /**
+     * Run with before.
+     *
+     * @return array
+     */
+    public static function runWithAfter(): array
+    {
+        return [
+            TypeHintStripper::class => [
+                'union' => true
+            ]
+        ];
+    }
+}
diff --git a/src/Traverser.php b/src/Traverser.php
index fd35580..d61b9c6 100644
--- a/src/Traverser.php
+++ b/src/Traverser.php
@@ -96,6 +96,7 @@ class Traverser
         }
         $ast = new RootNode($this->parser->parse(\file_get_contents($file)));
         $context = new Context;
+        $context->parents->push($ast);
         foreach ($reducedQueue as $queue) {
             $this->traverseNode($ast, $queue, $context);
         }
@@ -106,7 +107,7 @@ class Traverser
      * @param Node             &$node   Node
      * @param SplQueue<Plugin> $plugins Plugins
      * @param Context          $context Context
-     * 
+     *
      * @return void
      */
     public function traverseNode(Node &$node, SplQueue $plugins, Context $context): void
@@ -134,10 +135,15 @@ class Traverser
 
             $subNode = &$node->{$name};
             if (\is_array($subNode)) {
-                foreach ($subNode as $index => &$subNodeNode) {
+                for ($index = 0; $index < \count($subNode);) {
                     $node->setAttribute('currentNodeIndex', $index);
                     $this->traverseNode($subNodeNode, $plugins, $context);
+                    $index = $node->getAttribute('currentNodeIndex');
+                    do {
+                        $index++;
+                    } while (\in_array($index, $node->getAttribute('skipNodes', [])));
                 }
+                $node->setAttribute('skipNodes', []);
             } else {
                 $this->traverseNode($subNode, $plugins, $context);
             }