Moved GraphQL\Utils to GraphQL\Utils\Utils

UPGRADE.md

@@ -1,5 +1,9 @@
 # Upgrade
 
+## Upgrade v0.9.x > v0.10.x
+### Deprecated: GraphQL\Utils moved to GraphQL\Utils\Utils
+Old class still exists, but triggers deprecation warning.
+
 ## Upgrade v0.7.x > v0.8.x
 All of those changes apply to those who extends various parts of this library.
 If you only use the library and don't try to extend it - everything should work without breaks.

benchmarks/Utils/QueryGenerator.php

@@ -12,7 +12,7 @@ use GraphQL\Type\Definition\FieldDefinition;
 use GraphQL\Type\Definition\InterfaceType;
 use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Type\Definition\WrappingType;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class QueryGenerator
 {

docs/type-system/scalar-types.md

@@ -44,7 +44,7 @@ namespace MyApp;
 use GraphQL\Error\Error;
 use GraphQL\Language\AST\StringValueNode;
 use GraphQL\Type\Definition\ScalarType;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class EmailType extends ScalarType
 {

examples/01-blog/Blog/AppContext.php

@@ -1,9 +1,7 @@
 <?php
 namespace GraphQL\Examples\Blog;
 
-use GraphQL\Examples\Blog\Data\DataSource;
 use GraphQL\Examples\Blog\Data\User;
-use GraphQL\Utils;
 
 /**
  * Class AppContext

examples/01-blog/Blog/Data/Comment.php

@@ -2,7 +2,7 @@
 namespace GraphQL\Examples\Blog\Data;
 
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class Comment
 {

examples/01-blog/Blog/Data/Image.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Examples\Blog\Data;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class Image
 {

examples/01-blog/Blog/Data/Story.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Examples\Blog\Data;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class Story
 {

examples/01-blog/Blog/Data/User.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Examples\Blog\Data;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class User
 {

examples/01-blog/Blog/Type/Scalar/EmailType.php

@@ -4,7 +4,7 @@ namespace GraphQL\Examples\Blog\Type\Scalar;
 use GraphQL\Error\Error;
 use GraphQL\Language\AST\StringValueNode;
 use GraphQL\Type\Definition\CustomScalarType;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class EmailType
 {

examples/01-blog/Blog/Type/Scalar/UrlType.php

@@ -5,7 +5,7 @@ use GraphQL\Error\Error;
 use GraphQL\Language\AST\Node;
 use GraphQL\Language\AST\StringValueNode;
 use GraphQL\Type\Definition\ScalarType;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class UrlType extends ScalarType
 {

src/Error/Error.php

@@ -3,7 +3,7 @@ namespace GraphQL\Error;
 
 use GraphQL\Language\Source;
 use GraphQL\Language\SourceLocation;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class Error

src/Error/FormattedError.php

@@ -4,7 +4,7 @@ namespace GraphQL\Error;
 use GraphQL\Language\SourceLocation;
 use GraphQL\Type\Definition\Type;
 use GraphQL\Type\Definition\WrappingType;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class FormattedError
@@ -68,7 +68,7 @@ class FormattedError
         // Remove invariant entries as they don't provide much value:
         if (
             isset($trace[0]['function']) && isset($trace[0]['class']) &&
-            ('GraphQL\Utils::invariant' === $trace[0]['class'].'::'.$trace[0]['function'])) {
+            ('GraphQL\Utils\Utils::invariant' === $trace[0]['class'].'::'.$trace[0]['function'])) {
             array_shift($trace);
         }
 

src/Executor/Executor.php

@@ -27,7 +27,8 @@ use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Type\Definition\ResolveInfo;
 use GraphQL\Type\Definition\Type;
 use GraphQL\Type\Introspection;
-use GraphQL\Utils;
+use GraphQL\Utils\TypeInfo;
+use GraphQL\Utils\Utils;
 
 /**
  * Terminology
@@ -609,7 +610,7 @@ class Executor
             return true;
         }
 
-        $conditionalType = Utils\TypeInfo::typeFromAST($this->exeContext->schema, $typeConditionNode);
+        $conditionalType = TypeInfo::typeFromAST($this->exeContext->schema, $typeConditionNode);
         if ($conditionalType === $type) {
             return true;
         }

src/Executor/Promise/Adapter/ReactPromiseAdapter.php

@@ -3,7 +3,7 @@ namespace GraphQL\Executor\Promise\Adapter;
 
 use GraphQL\Executor\Promise\Promise;
 use GraphQL\Executor\Promise\PromiseAdapter;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 use React\Promise\Promise as ReactPromise;
 use React\Promise\PromiseInterface as ReactPromiseInterface;
 

src/Executor/Promise/Adapter/SyncPromise.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Executor\Promise\Adapter;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class SyncPromise

src/Executor/Promise/Adapter/SyncPromiseAdapter.php

@@ -5,7 +5,7 @@ use GraphQL\Deferred;
 use GraphQL\Error\InvariantViolation;
 use GraphQL\Executor\Promise\Promise;
 use GraphQL\Executor\Promise\PromiseAdapter;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class SyncPromiseAdapter

src/Executor/Promise/Promise.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Executor\Promise;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Convenience wrapper for promises represented by Promise Adapter

src/Executor/Values.php

@@ -23,7 +23,9 @@ use GraphQL\Type\Definition\LeafType;
 use GraphQL\Type\Definition\ListOfType;
 use GraphQL\Type\Definition\NonNull;
 use GraphQL\Type\Definition\Type;
-use GraphQL\Utils;
+use GraphQL\Utils\AST;
+use GraphQL\Utils\TypeInfo;
+use GraphQL\Utils\Utils;
 use GraphQL\Validator\DocumentValidator;
 
 class Values
@@ -44,7 +46,7 @@ class Values
         $coercedValues = [];
         foreach ($definitionNodes as $definitionNode) {
             $varName = $definitionNode->variable->name->value;
-            $varType = Utils\TypeInfo::typeFromAST($schema, $definitionNode->type);
+            $varType = TypeInfo::typeFromAST($schema, $definitionNode->type);
 
             if (!Type::isInputType($varType)) {
                 throw new Error(
@@ -57,7 +59,7 @@ class Values
             if (!array_key_exists($varName, $inputs)) {
                 $defaultValue = $definitionNode->defaultValue;
                 if ($defaultValue) {
-                    $coercedValues[$varName] = Utils\AST::valueFromAST($defaultValue, $varType);
+                    $coercedValues[$varName] = AST::valueFromAST($defaultValue, $varType);
                 }
                 if ($varType instanceof NonNull) {
                     throw new Error(
@@ -148,7 +150,7 @@ class Values
                 }
             } else {
                 $valueNode = $argumentNode->value;
-                $coercedValue = Utils\AST::valueFromAST($valueNode, $argType, $variableValues);
+                $coercedValue = AST::valueFromAST($valueNode, $argType, $variableValues);
                 if ($coercedValue === $undefined) {
                     $errors = DocumentValidator::isValidLiteralValue($argType, $valueNode);
                     $message = !empty($errors) ? ("\n" . implode("\n", $errors)) : '';
@@ -191,7 +193,7 @@ class Values
     }
 
     /**
-     * @deprecated as of 8.0 (Moved to Utils\AST::valueFromAST)
+     * @deprecated as of 8.0 (Moved to \GraphQL\Utils\AST::valueFromAST)
      *
      * @param $valueNode
      * @param InputType $type
@@ -200,7 +202,7 @@ class Values
      */
     public static function valueFromAST($valueNode, InputType $type, $variables = null)
     {
-        return Utils\AST::valueFromAST($valueNode, $type, $variables);
+        return AST::valueFromAST($valueNode, $type, $variables);
     }
 
     /**

src/Language/AST/Node.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Language\AST;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 abstract class Node
 {

src/Language/Lexer.php

@@ -2,7 +2,7 @@
 namespace GraphQL\Language;
 
 use GraphQL\Error\SyntaxError;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * A Lexer is a stateful stream generator in that every time

src/Language/Source.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Language;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class Source
 {

src/Schema.php

@@ -10,6 +10,8 @@ use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Type\Definition\Type;
 use GraphQL\Type\Definition\UnionType;
 use GraphQL\Type\Introspection;
+use GraphQL\Utils\TypeInfo;
+use GraphQL\Utils\Utils;
 
 /**
  * Schema Definition
@@ -235,7 +237,7 @@ class Schema
         }
         $typeMap = [];
         foreach ($initialTypes as $type) {
-            $typeMap = Utils\TypeInfo::extractTypes($type, $typeMap);
+            $typeMap = TypeInfo::extractTypes($type, $typeMap);
         }
         return $typeMap + Type::getInternalTypes();
     }

src/Schema/Config.php

@@ -4,7 +4,7 @@ namespace GraphQL\Schema;
 use GraphQL\Type\Definition\Directive;
 use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Type\Definition\Type;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class Config

src/Schema/Descriptor.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Schema;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class Descriptor implements \JsonSerializable
 {

src/Server.php

@@ -13,6 +13,7 @@ use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Type\Definition\Type;
 use GraphQL\Type\Resolution;
 use GraphQL\Validator\DocumentValidator;
+use GraphQL\Utils\Utils;
 
 class Server
 {

src/Type/Definition/Config.php

@@ -3,7 +3,7 @@ namespace GraphQL\Type\Definition;
 
 use GraphQL\Error\InvariantViolation;
 use GraphQL\Error\Warning;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class Config

src/Type/Definition/EnumType.php

@@ -2,7 +2,8 @@
 namespace GraphQL\Type\Definition;
 
 use GraphQL\Language\AST\EnumValueNode;
-use GraphQL\Utils;
+use GraphQL\Utils\MixedStore;
+use GraphQL\Utils\Utils;
 
 /**
  * Class EnumType
@@ -16,7 +17,7 @@ class EnumType extends Type implements InputType, OutputType, LeafType
     private $values;
 
     /**
-     * @var Utils\MixedStore<mixed, EnumValueDefinition>
+     * @var MixedStore<mixed, EnumValueDefinition>
      */
     private $valueLookup;
 
@@ -138,12 +139,12 @@ class EnumType extends Type implements InputType, OutputType, LeafType
     }
 
     /**
-     * @return Utils\MixedStore<mixed, EnumValueDefinition>
+     * @return MixedStore<mixed, EnumValueDefinition>
      */
     private function getValueLookup()
     {
         if (null === $this->valueLookup) {
-            $this->valueLookup = new Utils\MixedStore();
+            $this->valueLookup = new MixedStore();
 
             foreach ($this->getValues() as $valueName => $value) {
                 $this->valueLookup->offsetSet($value->value, $value);

src/Type/Definition/EnumValueDefinition.php

@@ -1,6 +1,6 @@
 <?php
 namespace GraphQL\Type\Definition;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class EnumValueDefinition

src/Type/Definition/FieldDefinition.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 use GraphQL\Error\InvariantViolation;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class FieldDefinition

src/Type/Definition/FloatType.php

@@ -4,7 +4,7 @@ namespace GraphQL\Type\Definition;
 use GraphQL\Error\UserError;
 use GraphQL\Language\AST\FloatValueNode;
 use GraphQL\Language\AST\IntValueNode;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class FloatType

src/Type/Definition/InputObjectType.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class InputObjectType

src/Type/Definition/IntType.php

@@ -4,7 +4,7 @@ namespace GraphQL\Type\Definition;
 use GraphQL\Error\InvariantViolation;
 use GraphQL\Error\UserError;
 use GraphQL\Language\AST\IntValueNode;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class IntType

src/Type/Definition/InterfaceType.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class InterfaceType

src/Type/Definition/ListOfType.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class ListOfType

src/Type/Definition/NonNull.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class NonNull

src/Type/Definition/ObjectType.php

@@ -2,7 +2,7 @@
 namespace GraphQL\Type\Definition;
 use GraphQL\Error\InvariantViolation;
 use GraphQL\Error\UserError;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 
 /**

src/Type/Definition/ResolveInfo.php

@@ -9,7 +9,7 @@ use GraphQL\Language\AST\InlineFragmentNode;
 use GraphQL\Language\AST\OperationDefinitionNode;
 use GraphQL\Language\AST\SelectionSetNode;
 use GraphQL\Schema;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class ResolveInfo

src/Type/Definition/ScalarType.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Scalar Type Definition

src/Type/Definition/Type.php

@@ -2,7 +2,7 @@
 namespace GraphQL\Type\Definition;
 
 use GraphQL\Error\InvariantViolation;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /*
 export type GraphQLType =

src/Type/Definition/UnionType.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Type\Definition;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class UnionType

src/Type/EagerResolution.php

@@ -9,7 +9,8 @@ use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Type\Definition\Type;
 use GraphQL\Type\Definition\UnionType;
 use GraphQL\Type\Definition\WrappingType;
-use GraphQL\Utils;
+use GraphQL\Utils\TypeInfo;
+use GraphQL\Utils\Utils;
 
 /**
  * EXPERIMENTAL!
@@ -38,7 +39,7 @@ class EagerResolution implements Resolution
     {
         $typeMap = [];
         foreach ($initialTypes as $type) {
-            $typeMap = Utils\TypeInfo::extractTypes($type, $typeMap);
+            $typeMap = TypeInfo::extractTypes($type, $typeMap);
         }
         $this->typeMap = $typeMap + Type::getInternalTypes();
 

src/Type/Introspection.php

@@ -20,7 +20,7 @@ use GraphQL\Type\Definition\ScalarType;
 use GraphQL\Type\Definition\Type;
 use GraphQL\Type\Definition\UnionType;
 use GraphQL\Type\Definition\WrappingType;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 use GraphQL\Utils\AST;
 
 class TypeKind {

src/Type/LazyResolution.php

@@ -5,7 +5,7 @@ use GraphQL\Error\InvariantViolation;
 use GraphQL\Type\Definition\AbstractType;
 use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Type\Definition\Type;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * EXPERIMENTAL!

src/Utils.php

@@ -1,372 +1,11 @@
 <?php
 namespace GraphQL;
 
-use GraphQL\Error\InvariantViolation;
+trigger_error(
-use GraphQL\Error\Warning;
+    'GraphQL\Utils was moved to GraphQL\Utils\Utils and will be deleted on next release',
-use GraphQL\Type\Definition\Type;
+    E_USER_DEPRECATED
-use GraphQL\Type\Definition\WrappingType;
+);
-use GraphQL\Utils\SchemaUtils;
-use \Traversable, \InvalidArgumentException;
 
-class Utils
+class Utils extends \GraphQL\Utils\Utils
 {
-    public static function undefined()
-    {
-        static $undefined;
-        return $undefined ?: $undefined = new \stdClass();
-    }
-
-    /**
-     * @param object $obj
-     * @param array  $vars
-     * @param array  $requiredKeys
-     *
-     * @return array
-     */
-    public static function assign($obj, array $vars, array $requiredKeys = [])
-    {
-        foreach ($requiredKeys as $key) {
-            if (!isset($vars[$key])) {
-                throw new InvalidArgumentException("Key {$key} is expected to be set and not to be null");
-            }
-        }
-
-        foreach ($vars as $key => $value) {
-            if (!property_exists($obj, $key)) {
-                $cls = get_class($obj);
-                Warning::warn(
-                    "Trying to set non-existing property '$key' on class '$cls'",
-                    Warning::ASSIGN_WARNING
-                );
-            }
-            $obj->{$key} = $value;
-        }
-        return $obj;
-    }
-
-    /**
-     * @param array|Traversable $traversable
-     * @param callable $predicate
-     * @return null
-     */
-    public static function find($traversable, callable $predicate)
-    {
-        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
-
-        foreach ($traversable as $key => $value) {
-            if ($predicate($value, $key)) {
-                return $value;
-            }
-        }
-        return null;
-    }
-
-    /**
-     * @param $traversable
-     * @param callable $predicate
-     * @return array
-     * @throws \Exception
-     */
-    public static function filter($traversable, callable $predicate)
-    {
-        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
-
-        $result = [];
-        $assoc = false;
-        foreach ($traversable as $key => $value) {
-            if (!$assoc && !is_int($key)) {
-                $assoc = true;
-            }
-            if ($predicate($value, $key)) {
-                $result[$key] = $value;
-            }
-        }
-
-        return $assoc ? $result : array_values($result);
-    }
-
-    /**
-     * @param array|\Traversable $traversable
-     * @param callable $fn function($value, $key) => $newValue
-     * @return array
-     * @throws \Exception
-     */
-    public static function map($traversable, callable $fn)
-    {
-        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
-
-        $map = [];
-        foreach ($traversable as $key => $value) {
-            $map[$key] = $fn($value, $key);
-        }
-        return $map;
-    }
-
-    /**
-     * @param $traversable
-     * @param callable $fn
-     * @return array
-     * @throws \Exception
-     */
-    public static function mapKeyValue($traversable, callable $fn)
-    {
-        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
-
-        $map = [];
-        foreach ($traversable as $key => $value) {
-            list($newKey, $newValue) = $fn($value, $key);
-            $map[$newKey] = $newValue;
-        }
-        return $map;
-    }
-
-    /**
-     * @param $traversable
-     * @param callable $keyFn function($value, $key) => $newKey
-     * @return array
-     * @throws \Exception
-     */
-    public static function keyMap($traversable, callable $keyFn)
-    {
-        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
-
-        $map = [];
-        foreach ($traversable as $key => $value) {
-            $newKey = $keyFn($value, $key);
-            if (is_scalar($newKey)) {
-                $map[$newKey] = $value;
-            }
-        }
-        return $map;
-    }
-
-    /**
-     * @param $traversable
-     * @param callable $fn
-     */
-    public static function each($traversable, callable $fn)
-    {
-        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
-
-        foreach ($traversable as $key => $item) {
-            $fn($item, $key);
-        }
-    }
-
-    /**
-     * Splits original traversable to several arrays with keys equal to $keyFn return
-     *
-     * E.g. Utils::groupBy([1, 2, 3, 4, 5], function($value) {return $value % 3}) will output:
-     * [
-     *    1 => [1, 4],
-     *    2 => [2, 5],
-     *    0 => [3],
-     * ]
-     *
-     * $keyFn is also allowed to return array of keys. Then value will be added to all arrays with given keys
-     *
-     * @param $traversable
-     * @param callable $keyFn function($value, $key) => $newKey(s)
-     * @return array
-     */
-    public static function groupBy($traversable, callable $keyFn)
-    {
-        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
-
-        $grouped = [];
-        foreach ($traversable as $key => $value) {
-            $newKeys = (array) $keyFn($value, $key);
-            foreach ($newKeys as $key) {
-                $grouped[$key][] = $value;
-            }
-        }
-
-        return $grouped;
-    }
-
-    public static function keyValMap($traversable, callable $keyFn, callable $valFn)
-    {
-        return array_reduce($traversable, function ($map, $item) use ($keyFn, $valFn) {
-            $map[$keyFn($item)] = $valFn($item);
-            return $map;
-        }, []);
-    }
-
-    /**
-     * @param $traversable
-     * @param callable $predicate
-     * @return bool
-     */
-    public static function every($traversable, callable $predicate)
-    {
-        foreach ($traversable as $key => $value) {
-            if (!$predicate($value, $key)) {
-                return false;
-            }
-        }
-        return true;
-    }
-
-    /**
-     * @param $test
-     * @param string $message
-     * @param mixed $sprintfParam1
-     * @param mixed $sprintfParam2 ...
-     * @throws \Exception
-     */
-    public static function invariant($test, $message = '')
-    {
-        if (!$test) {
-            if (func_num_args() > 2) {
-                $args = func_get_args();
-                array_shift($args);
-                $message = call_user_func_array('sprintf', $args);
-            }
-            throw new InvariantViolation($message);
-        }
-    }
-
-    /**
-     * @param $var
-     * @return string
-     */
-    public static function getVariableType($var)
-    {
-        if ($var instanceof Type) {
-            // FIXME: Replace with schema printer call
-            if ($var instanceof WrappingType) {
-                $var = $var->getWrappedType(true);
-            }
-            return $var->name;
-        }
-        return is_object($var) ? get_class($var) : gettype($var);
-    }
-
-    /**
-     * @param $var
-     * @return string
-     */
-    public static function printSafe($var)
-    {
-        if ($var instanceof Type) {
-            return $var->toString();
-        }
-        if (is_object($var)) {
-            return 'instance of ' . get_class($var);
-        }
-        if ('' === $var) {
-            return '(empty string)';
-        }
-        if (is_string($var)) {
-            return "\"$var\"";
-        }
-        if (is_scalar($var)) {
-            return (string) $var;
-        }
-        if (null === $var) {
-            return 'null';
-        }
-        return gettype($var);
-    }
-
-    /**
-     * UTF-8 compatible chr()
-     *
-     * @param string $ord
-     * @param string $encoding
-     * @return string
-     */
-    public static function chr($ord, $encoding = 'UTF-8')
-    {
-        if ($ord <= 255) {
-            return chr($ord);
-        }
-        if ($encoding === 'UCS-4BE') {
-            return pack("N", $ord);
-        } else {
-            return mb_convert_encoding(self::chr($ord, 'UCS-4BE'), $encoding, 'UCS-4BE');
-        }
-    }
-
-    /**
-     * UTF-8 compatible ord()
-     *
-     * @param string $char
-     * @param string $encoding
-     * @return mixed
-     */
-    public static function ord($char, $encoding = 'UTF-8')
-    {
-        if (!$char && '0' !== $char) {
-            return 0;
-        }
-        if (!isset($char[1])) {
-            return ord($char);
-        }
-        if ($encoding !== 'UCS-4BE') {
-            $char = mb_convert_encoding($char, 'UCS-4BE', $encoding);
-        }
-        list(, $ord) = unpack('N', $char);
-        return $ord;
-    }
-
-    /**
-     * Returns UTF-8 char code at given $positing of the $string
-     *
-     * @param $string
-     * @param $position
-     * @return mixed
-     */
-    public static function charCodeAt($string, $position)
-    {
-        $char = mb_substr($string, $position, 1, 'UTF-8');
-        return self::ord($char);
-    }
-
-    /**
-     * @param $code
-     * @return string
-     */
-    public static function printCharCode($code)
-    {
-        if (null === $code) {
-            return '<EOF>';
-        }
-        return $code < 0x007F
-            // Trust JSON for ASCII.
-             ? json_encode(Utils::chr($code))
-            // Otherwise print the escaped form.
-            : '"\\u' . dechex($code) . '"';
-    }
-
-    /**
-     * @param $name
-     * @param bool $isIntrospection
-     * @throws Error
-     */
-    public static function assertValidName($name, $isIntrospection = false)
-    {
-        $regex = '/^[_a-zA-Z][_a-zA-Z0-9]*$/';
-
-        if (!$name || !is_string($name)) {
-            throw new InvariantViolation(
-                "Must be named. Unexpected name: " . self::printSafe($name)
-            );
-        }
-
-        if (!$isIntrospection && isset($name[1]) && $name[0] === '_' && $name[1] === '_') {
-            Warning::warnOnce(
-                'Name "'.$name.'" must not begin with "__", which is reserved by ' .
-                'GraphQL introspection. In a future release of graphql this will ' .
-                'become an exception',
-                Warning::NAME_WARNING
-            );
-        }
-
-        if (!preg_match($regex, $name)) {
-            throw new InvariantViolation(
-                'Names must match /^[_a-zA-Z][_a-zA-Z0-9]*$/ but "'.$name.'" does not.'
-            );
-        }
-    }
 }

src/Utils/AST.php

@@ -22,7 +22,7 @@ use GraphQL\Type\Definition\InputType;
 use GraphQL\Type\Definition\LeafType;
 use GraphQL\Type\Definition\ListOfType;
 use GraphQL\Type\Definition\NonNull;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class AST

src/Utils/BuildSchema.php

@@ -31,7 +31,6 @@ use GraphQL\Type\Definition\CustomScalarType;
 use GraphQL\Type\Definition\Type;
 use GraphQL\Type\Definition\UnionType;
 use GraphQL\Type\Introspection;
-use GraphQL\Utils;
 
 /**
  * Class BuildSchema
@@ -394,7 +393,7 @@ class BuildSchema
                     'description' => $this->getDescription($value)
                 ];
                 if (isset($value->defaultValue)) {
-                    $config['defaultValue'] = Utils\AST::valueFromAST($value->defaultValue, $type);
+                    $config['defaultValue'] = AST::valueFromAST($value->defaultValue, $type);
                 }
                 return $config;
             }

src/Utils/MixedStore.php

@@ -1,6 +1,6 @@
 <?php
 namespace GraphQL\Utils;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Similar to PHP array, but allows any type of data to act as key (including arrays, objects, scalars)

src/Utils/SchemaPrinter.php

@@ -12,7 +12,7 @@ use GraphQL\Type\Definition\ScalarType;
 use GraphQL\Type\Definition\Type;
 use GraphQL\Type\Definition\UnionType;
 use GraphQL\Type\Definition\Directive;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class SchemaPrinter

src/Utils/TypeInfo.php

@@ -24,7 +24,7 @@ use GraphQL\Type\Definition\Type;
 use GraphQL\Type\Definition\UnionType;
 use GraphQL\Type\Definition\WrappingType;
 use GraphQL\Type\Introspection;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 /**
  * Class TypeInfo

src/Utils/Utils.php

@@ -0,0 +1,371 @@
+<?php
+namespace GraphQL\Utils;
+
+use GraphQL\Error\InvariantViolation;
+use GraphQL\Error\Warning;
+use GraphQL\Type\Definition\Type;
+use GraphQL\Type\Definition\WrappingType;
+use \Traversable, \InvalidArgumentException;
+
+class Utils
+{
+    public static function undefined()
+    {
+        static $undefined;
+        return $undefined ?: $undefined = new \stdClass();
+    }
+
+    /**
+     * @param object $obj
+     * @param array  $vars
+     * @param array  $requiredKeys
+     *
+     * @return array
+     */
+    public static function assign($obj, array $vars, array $requiredKeys = [])
+    {
+        foreach ($requiredKeys as $key) {
+            if (!isset($vars[$key])) {
+                throw new InvalidArgumentException("Key {$key} is expected to be set and not to be null");
+            }
+        }
+
+        foreach ($vars as $key => $value) {
+            if (!property_exists($obj, $key)) {
+                $cls = get_class($obj);
+                Warning::warn(
+                    "Trying to set non-existing property '$key' on class '$cls'",
+                    Warning::ASSIGN_WARNING
+                );
+            }
+            $obj->{$key} = $value;
+        }
+        return $obj;
+    }
+
+    /**
+     * @param array|Traversable $traversable
+     * @param callable $predicate
+     * @return null
+     */
+    public static function find($traversable, callable $predicate)
+    {
+        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
+
+        foreach ($traversable as $key => $value) {
+            if ($predicate($value, $key)) {
+                return $value;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * @param $traversable
+     * @param callable $predicate
+     * @return array
+     * @throws \Exception
+     */
+    public static function filter($traversable, callable $predicate)
+    {
+        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
+
+        $result = [];
+        $assoc = false;
+        foreach ($traversable as $key => $value) {
+            if (!$assoc && !is_int($key)) {
+                $assoc = true;
+            }
+            if ($predicate($value, $key)) {
+                $result[$key] = $value;
+            }
+        }
+
+        return $assoc ? $result : array_values($result);
+    }
+
+    /**
+     * @param array|\Traversable $traversable
+     * @param callable $fn function($value, $key) => $newValue
+     * @return array
+     * @throws \Exception
+     */
+    public static function map($traversable, callable $fn)
+    {
+        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
+
+        $map = [];
+        foreach ($traversable as $key => $value) {
+            $map[$key] = $fn($value, $key);
+        }
+        return $map;
+    }
+
+    /**
+     * @param $traversable
+     * @param callable $fn
+     * @return array
+     * @throws \Exception
+     */
+    public static function mapKeyValue($traversable, callable $fn)
+    {
+        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
+
+        $map = [];
+        foreach ($traversable as $key => $value) {
+            list($newKey, $newValue) = $fn($value, $key);
+            $map[$newKey] = $newValue;
+        }
+        return $map;
+    }
+
+    /**
+     * @param $traversable
+     * @param callable $keyFn function($value, $key) => $newKey
+     * @return array
+     * @throws \Exception
+     */
+    public static function keyMap($traversable, callable $keyFn)
+    {
+        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
+
+        $map = [];
+        foreach ($traversable as $key => $value) {
+            $newKey = $keyFn($value, $key);
+            if (is_scalar($newKey)) {
+                $map[$newKey] = $value;
+            }
+        }
+        return $map;
+    }
+
+    /**
+     * @param $traversable
+     * @param callable $fn
+     */
+    public static function each($traversable, callable $fn)
+    {
+        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
+
+        foreach ($traversable as $key => $item) {
+            $fn($item, $key);
+        }
+    }
+
+    /**
+     * Splits original traversable to several arrays with keys equal to $keyFn return
+     *
+     * E.g. Utils::groupBy([1, 2, 3, 4, 5], function($value) {return $value % 3}) will output:
+     * [
+     *    1 => [1, 4],
+     *    2 => [2, 5],
+     *    0 => [3],
+     * ]
+     *
+     * $keyFn is also allowed to return array of keys. Then value will be added to all arrays with given keys
+     *
+     * @param $traversable
+     * @param callable $keyFn function($value, $key) => $newKey(s)
+     * @return array
+     */
+    public static function groupBy($traversable, callable $keyFn)
+    {
+        self::invariant(is_array($traversable) || $traversable instanceof \Traversable, __METHOD__ . ' expects array or Traversable');
+
+        $grouped = [];
+        foreach ($traversable as $key => $value) {
+            $newKeys = (array) $keyFn($value, $key);
+            foreach ($newKeys as $key) {
+                $grouped[$key][] = $value;
+            }
+        }
+
+        return $grouped;
+    }
+
+    public static function keyValMap($traversable, callable $keyFn, callable $valFn)
+    {
+        return array_reduce($traversable, function ($map, $item) use ($keyFn, $valFn) {
+            $map[$keyFn($item)] = $valFn($item);
+            return $map;
+        }, []);
+    }
+
+    /**
+     * @param $traversable
+     * @param callable $predicate
+     * @return bool
+     */
+    public static function every($traversable, callable $predicate)
+    {
+        foreach ($traversable as $key => $value) {
+            if (!$predicate($value, $key)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * @param $test
+     * @param string $message
+     * @param mixed $sprintfParam1
+     * @param mixed $sprintfParam2 ...
+     * @throws \Exception
+     */
+    public static function invariant($test, $message = '')
+    {
+        if (!$test) {
+            if (func_num_args() > 2) {
+                $args = func_get_args();
+                array_shift($args);
+                $message = call_user_func_array('sprintf', $args);
+            }
+            throw new InvariantViolation($message);
+        }
+    }
+
+    /**
+     * @param $var
+     * @return string
+     */
+    public static function getVariableType($var)
+    {
+        if ($var instanceof Type) {
+            // FIXME: Replace with schema printer call
+            if ($var instanceof WrappingType) {
+                $var = $var->getWrappedType(true);
+            }
+            return $var->name;
+        }
+        return is_object($var) ? get_class($var) : gettype($var);
+    }
+
+    /**
+     * @param $var
+     * @return string
+     */
+    public static function printSafe($var)
+    {
+        if ($var instanceof Type) {
+            return $var->toString();
+        }
+        if (is_object($var)) {
+            return 'instance of ' . get_class($var);
+        }
+        if ('' === $var) {
+            return '(empty string)';
+        }
+        if (is_string($var)) {
+            return "\"$var\"";
+        }
+        if (is_scalar($var)) {
+            return (string) $var;
+        }
+        if (null === $var) {
+            return 'null';
+        }
+        return gettype($var);
+    }
+
+    /**
+     * UTF-8 compatible chr()
+     *
+     * @param string $ord
+     * @param string $encoding
+     * @return string
+     */
+    public static function chr($ord, $encoding = 'UTF-8')
+    {
+        if ($ord <= 255) {
+            return chr($ord);
+        }
+        if ($encoding === 'UCS-4BE') {
+            return pack("N", $ord);
+        } else {
+            return mb_convert_encoding(self::chr($ord, 'UCS-4BE'), $encoding, 'UCS-4BE');
+        }
+    }
+
+    /**
+     * UTF-8 compatible ord()
+     *
+     * @param string $char
+     * @param string $encoding
+     * @return mixed
+     */
+    public static function ord($char, $encoding = 'UTF-8')
+    {
+        if (!$char && '0' !== $char) {
+            return 0;
+        }
+        if (!isset($char[1])) {
+            return ord($char);
+        }
+        if ($encoding !== 'UCS-4BE') {
+            $char = mb_convert_encoding($char, 'UCS-4BE', $encoding);
+        }
+        list(, $ord) = unpack('N', $char);
+        return $ord;
+    }
+
+    /**
+     * Returns UTF-8 char code at given $positing of the $string
+     *
+     * @param $string
+     * @param $position
+     * @return mixed
+     */
+    public static function charCodeAt($string, $position)
+    {
+        $char = mb_substr($string, $position, 1, 'UTF-8');
+        return self::ord($char);
+    }
+
+    /**
+     * @param $code
+     * @return string
+     */
+    public static function printCharCode($code)
+    {
+        if (null === $code) {
+            return '<EOF>';
+        }
+        return $code < 0x007F
+            // Trust JSON for ASCII.
+            ? json_encode(Utils::chr($code))
+            // Otherwise print the escaped form.
+            : '"\\u' . dechex($code) . '"';
+    }
+
+    /**
+     * @param $name
+     * @param bool $isIntrospection
+     * @throws Error
+     */
+    public static function assertValidName($name, $isIntrospection = false)
+    {
+        $regex = '/^[_a-zA-Z][_a-zA-Z0-9]*$/';
+
+        if (!$name || !is_string($name)) {
+            throw new InvariantViolation(
+                "Must be named. Unexpected name: " . self::printSafe($name)
+            );
+        }
+
+        if (!$isIntrospection && isset($name[1]) && $name[0] === '_' && $name[1] === '_') {
+            Warning::warnOnce(
+                'Name "'.$name.'" must not begin with "__", which is reserved by ' .
+                'GraphQL introspection. In a future release of graphql this will ' .
+                'become an exception',
+                Warning::NAME_WARNING
+            );
+        }
+
+        if (!preg_match($regex, $name)) {
+            throw new InvariantViolation(
+                'Names must match /^[_a-zA-Z][_a-zA-Z0-9]*$/ but "'.$name.'" does not.'
+            );
+        }
+    }
+}

src/Validator/DocumentValidator.php

@@ -15,7 +15,7 @@ use GraphQL\Type\Definition\LeafType;
 use GraphQL\Type\Definition\ListOfType;
 use GraphQL\Type\Definition\NonNull;
 use GraphQL\Type\Definition\Type;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 use GraphQL\Utils\TypeInfo;
 use GraphQL\Validator\Rules\ArgumentsOfCorrectType;
 use GraphQL\Validator\Rules\DefaultValuesOfCorrectType;

src/Validator/Rules/FieldsOnCorrectType.php

@@ -6,7 +6,7 @@ use GraphQL\Language\AST\FieldNode;
 use GraphQL\Language\AST\NodeKind;
 use GraphQL\Schema;
 use GraphQL\Type\Definition\AbstractType;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 use GraphQL\Validator\ValidationContext;
 
 class FieldsOnCorrectType

src/Validator/Rules/KnownArgumentNames.php

@@ -4,7 +4,7 @@ namespace GraphQL\Validator\Rules;
 use GraphQL\Error\Error;
 use GraphQL\Language\AST\ArgumentNode;
 use GraphQL\Language\AST\NodeKind;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 use GraphQL\Validator\ValidationContext;
 
 class KnownArgumentNames

src/Validator/Rules/LoneAnonymousOperation.php

@@ -6,7 +6,7 @@ use GraphQL\Language\AST\DocumentNode;
 use GraphQL\Language\AST\Node;
 use GraphQL\Language\AST\NodeKind;
 use GraphQL\Language\AST\OperationDefinitionNode;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 use GraphQL\Validator\ValidationContext;
 
 /**

src/Validator/Rules/NoFragmentCycles.php

@@ -15,7 +15,7 @@ use GraphQL\Language\AST\FragmentSpreadNode;
 use GraphQL\Language\AST\Node;
 use GraphQL\Language\AST\NodeKind;
 use GraphQL\Language\Visitor;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 use GraphQL\Validator\ValidationContext;
 
 class NoFragmentCycles

src/Validator/Rules/OverlappingFieldsCanBeMerged.php

@@ -18,7 +18,7 @@ use GraphQL\Type\Definition\NonNull;
 use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Type\Definition\OutputType;
 use GraphQL\Type\Definition\Type;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 use GraphQL\Utils\PairSet;
 use GraphQL\Utils\TypeInfo;
 use GraphQL\Validator\ValidationContext;

src/Validator/Rules/ProvidedNonNullArguments.php

@@ -9,7 +9,7 @@ use GraphQL\Language\AST\Node;
 use GraphQL\Language\AST\NodeKind;
 use GraphQL\Language\Visitor;
 use GraphQL\Type\Definition\NonNull;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 use GraphQL\Validator\ValidationContext;
 
 class ProvidedNonNullArguments

src/Validator/Rules/VariablesAreInputTypes.php

@@ -9,7 +9,7 @@ use GraphQL\Language\AST\VariableDefinitionNode;
 use GraphQL\Language\Printer;
 use GraphQL\Type\Definition\InputType;
 use GraphQL\Type\Definition\Type;
-use GraphQL\Utils;
+use GraphQL\Utils\TypeInfo;
 use GraphQL\Validator\ValidationContext;
 
 class VariablesAreInputTypes
@@ -23,7 +23,7 @@ class VariablesAreInputTypes
     {
         return [
             NodeKind::VARIABLE_DEFINITION => function(VariableDefinitionNode $node) use ($context) {
-                $type = Utils\TypeInfo::typeFromAST($context->getSchema(), $node->type);
+                $type = TypeInfo::typeFromAST($context->getSchema(), $node->type);
 
                 // If the variable type is not an input type, return an error.
                 if ($type && !Type::isInputType($type)) {

tests/Executor/DeferredFieldsTest.php

@@ -9,7 +9,7 @@ use GraphQL\Schema;
 use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Type\Definition\ResolveInfo;
 use GraphQL\Type\Definition\Type;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class DeferredFieldsTest extends \PHPUnit_Framework_TestCase
 {

tests/Language/LexerTest.php

@@ -5,7 +5,7 @@ use GraphQL\Language\Lexer;
 use GraphQL\Language\Source;
 use GraphQL\Language\Token;
 use GraphQL\Error\SyntaxError;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class LexerTest extends \PHPUnit_Framework_TestCase
 {

tests/Language/ParserTest.php

@@ -13,7 +13,7 @@ use GraphQL\Language\Parser;
 use GraphQL\Language\Source;
 use GraphQL\Language\SourceLocation;
 use GraphQL\Error\SyntaxError;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class ParserTest extends \PHPUnit_Framework_TestCase
 {

tests/Type/ConfigTest.php

@@ -8,7 +8,7 @@ use GraphQL\Type\Definition\InputObjectType;
 use GraphQL\Type\Definition\InterfaceType;
 use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Type\Definition\Type;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class ConfigTest extends \PHPUnit_Framework_TestCase
 {

tests/Type/DefinitionTest.php

@@ -13,7 +13,7 @@ use GraphQL\Type\Definition\NonNull;
 use GraphQL\Type\Definition\ObjectType;
 use GraphQL\Type\Definition\Type;
 use GraphQL\Type\Definition\UnionType;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class DefinitionTest extends \PHPUnit_Framework_TestCase
 {

tests/Utils/MixedStoreTest.php

@@ -2,7 +2,7 @@
 namespace GraphQL\Tests\Utils;
 
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 use GraphQL\Utils\MixedStore;
 
 class MixedStoreTest extends \PHPUnit_Framework_TestCase

tests/Utils/ValueFromAstTest.php

@@ -6,7 +6,7 @@ use GraphQL\Language\Parser;
 use GraphQL\Type\Definition\EnumType;
 use GraphQL\Type\Definition\InputObjectType;
 use GraphQL\Type\Definition\Type;
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 use GraphQL\Utils\AST;
 
 class ValueFromAstTest extends \PHPUnit_Framework_TestCase

tests/UtilsTest.php

@@ -1,7 +1,7 @@
 <?php
 namespace GraphQL\Tests;
 
-use GraphQL\Utils;
+use GraphQL\Utils\Utils;
 
 class UtilsTest extends \PHPUnit_Framework_TestCase
 {