sop / asn1

lib/ASN1/Type/Tagged/ExplicitTagging.php

Indentation +11 added lines, -11 removed lines

@@ -12,15 +12,15 @@
  */
 interface ExplicitTagging extends ElementBase
 {
-    /**
-     * Get explicitly tagged wrapped element.
-     *
-     * NOTE! Expectation checking is deprecated and shall be done
-     * with UnspecifiedType.
-     *
-     * @param int|null $expectedTag Expected tag of the underlying type
-     * @throws \UnexpectedValueException If expectation fails
-     * @return \ASN1\Type\UnspecifiedType
-     */
-    public function explicit($expectedTag = null): UnspecifiedType;
+	/**
+	 * Get explicitly tagged wrapped element.
+	 *
+	 * NOTE! Expectation checking is deprecated and shall be done
+	 * with UnspecifiedType.
+	 *
+	 * @param int|null $expectedTag Expected tag of the underlying type
+	 * @throws \UnexpectedValueException If expectation fails
+	 * @return \ASN1\Type\UnspecifiedType
+	 */
+	public function explicit($expectedTag = null): UnspecifiedType;
 }

lib/ASN1/Type/Tagged/ImplicitlyTaggedType.php

Indentation +47 added lines, -47 removed lines

@@ -16,55 +16,55 @@
  * decoding the data.
  */
 class ImplicitlyTaggedType extends ContextSpecificTaggedType implements 
-    ImplicitTagging
+	ImplicitTagging
 {
-    /**
-     * Constructor.
-     *
-     * @param int $tag
-     * @param Element $element
-     */
-    public function __construct($tag, Element $element)
-    {
-        $this->_typeTag = $tag;
-        $this->_element = $element;
-    }
+	/**
+	 * Constructor.
+	 *
+	 * @param int $tag
+	 * @param Element $element
+	 */
+	public function __construct($tag, Element $element)
+	{
+		$this->_typeTag = $tag;
+		$this->_element = $element;
+	}
     
-    /**
-     *
-     * @see \ASN1\Element::isConstructed()
-     * @return bool
-     */
-    public function isConstructed(): bool
-    {
-        // depends on the underlying type
-        return $this->_element->isConstructed();
-    }
+	/**
+	 *
+	 * @see \ASN1\Element::isConstructed()
+	 * @return bool
+	 */
+	public function isConstructed(): bool
+	{
+		// depends on the underlying type
+		return $this->_element->isConstructed();
+	}
     
-    /**
-     *
-     * @see \ASN1\Element::_encodedContentDER()
-     * @return string
-     */
-    protected function _encodedContentDER(): string
-    {
-        return $this->_element->_encodedContentDER();
-    }
+	/**
+	 *
+	 * @see \ASN1\Element::_encodedContentDER()
+	 * @return string
+	 */
+	protected function _encodedContentDER(): string
+	{
+		return $this->_element->_encodedContentDER();
+	}
     
-    /**
-     * {@inheritdoc}
-     * @see \ASN1\Type\Tagged\ImplicitTagging::implicit()
-     * @return UnspecifiedType
-     */
-    public function implicit($tag, int $class = Identifier::CLASS_UNIVERSAL): UnspecifiedType
-    {
-        $this->_element->expectType($tag);
-        if ($this->_element->typeClass() != $class) {
-            throw new \UnexpectedValueException(
-                sprintf("Type class %s expected, got %s.",
-                    Identifier::classToName($class),
-                    Identifier::classToName($this->_element->typeClass())));
-        }
-        return new UnspecifiedType($this->_element);
-    }
+	/**
+	 * {@inheritdoc}
+	 * @see \ASN1\Type\Tagged\ImplicitTagging::implicit()
+	 * @return UnspecifiedType
+	 */
+	public function implicit($tag, int $class = Identifier::CLASS_UNIVERSAL): UnspecifiedType
+	{
+		$this->_element->expectType($tag);
+		if ($this->_element->typeClass() != $class) {
+			throw new \UnexpectedValueException(
+				sprintf("Type class %s expected, got %s.",
+					Identifier::classToName($class),
+					Identifier::classToName($this->_element->typeClass())));
+		}
+		return new UnspecifiedType($this->_element);
+	}
 }

lib/ASN1/Type/Tagged/ExplicitlyTaggedType.php

Indentation +42 added lines, -42 removed lines

@@ -14,50 +14,50 @@
  * is not changed.
  */
 class ExplicitlyTaggedType extends ContextSpecificTaggedType implements 
-    ExplicitTagging
+	ExplicitTagging
 {
-    /**
-     * Constructor.
-     *
-     * @param int $tag Tag number
-     * @param Element $element Wrapped element
-     */
-    public function __construct($tag, Element $element)
-    {
-        $this->_typeTag = $tag;
-        $this->_element = $element;
-    }
+	/**
+	 * Constructor.
+	 *
+	 * @param int $tag Tag number
+	 * @param Element $element Wrapped element
+	 */
+	public function __construct($tag, Element $element)
+	{
+		$this->_typeTag = $tag;
+		$this->_element = $element;
+	}
     
-    /**
-     *
-     * @see \ASN1\Element::isConstructed()
-     * @return bool
-     */
-    public function isConstructed(): bool
-    {
-        return true;
-    }
+	/**
+	 *
+	 * @see \ASN1\Element::isConstructed()
+	 * @return bool
+	 */
+	public function isConstructed(): bool
+	{
+		return true;
+	}
     
-    /**
-     *
-     * @see \ASN1\Element::_encodedContentDER()
-     * @return string
-     */
-    protected function _encodedContentDER(): string
-    {
-        return $this->_element->toDER();
-    }
+	/**
+	 *
+	 * @see \ASN1\Element::_encodedContentDER()
+	 * @return string
+	 */
+	protected function _encodedContentDER(): string
+	{
+		return $this->_element->toDER();
+	}
     
-    /**
-     * {@inheritdoc}
-     * @see \ASN1\Type\Tagged\ExplicitTagging::explicit()
-     * @return UnspecifiedType
-     */
-    public function explicit($expectedTag = null): UnspecifiedType
-    {
-        if (isset($expectedTag)) {
-            $this->_element->expectType($expectedTag);
-        }
-        return new UnspecifiedType($this->_element);
-    }
+	/**
+	 * {@inheritdoc}
+	 * @see \ASN1\Type\Tagged\ExplicitTagging::explicit()
+	 * @return UnspecifiedType
+	 */
+	public function explicit($expectedTag = null): UnspecifiedType
+	{
+		if (isset($expectedTag)) {
+			$this->_element->expectType($expectedTag);
+		}
+		return new UnspecifiedType($this->_element);
+	}
 }

lib/ASN1/Type/Tagged/DERTaggedType.php

Indentation +91 added lines, -91 removed lines

@@ -20,104 +20,104 @@
  * May be encoded back to complete DER encoding.
  */
 class DERTaggedType extends TaggedType implements 
-    ExplicitTagging,
-    ImplicitTagging
+	ExplicitTagging,
+	ImplicitTagging
 {
-    /**
-     * Identifier.
-     *
-     * @var Identifier
-     */
-    private $_identifier;
+	/**
+	 * Identifier.
+	 *
+	 * @var Identifier
+	 */
+	private $_identifier;
     
-    /**
-     * DER data.
-     *
-     * @var string
-     */
-    private $_data;
+	/**
+	 * DER data.
+	 *
+	 * @var string
+	 */
+	private $_data;
     
-    /**
-     * Offset to data.
-     *
-     * @var int
-     */
-    private $_offset;
+	/**
+	 * Offset to data.
+	 *
+	 * @var int
+	 */
+	private $_offset;
     
-    /**
-     * Constructor.
-     *
-     * @param Identifier $identifier
-     * @param string $data
-     * @param int $offset Offset to next byte after identifier
-     */
-    public function __construct(Identifier $identifier, string $data, int $offset)
-    {
-        $this->_identifier = $identifier;
-        $this->_data = $data;
-        $this->_offset = $offset;
-        $this->_typeTag = intval($identifier->tag());
-    }
+	/**
+	 * Constructor.
+	 *
+	 * @param Identifier $identifier
+	 * @param string $data
+	 * @param int $offset Offset to next byte after identifier
+	 */
+	public function __construct(Identifier $identifier, string $data, int $offset)
+	{
+		$this->_identifier = $identifier;
+		$this->_data = $data;
+		$this->_offset = $offset;
+		$this->_typeTag = intval($identifier->tag());
+	}
     
-    /**
-     *
-     * @see \ASN1\Element::typeClass()
-     * @return int
-     */
-    public function typeClass(): int
-    {
-        return $this->_identifier->typeClass();
-    }
+	/**
+	 *
+	 * @see \ASN1\Element::typeClass()
+	 * @return int
+	 */
+	public function typeClass(): int
+	{
+		return $this->_identifier->typeClass();
+	}
     
-    /**
-     *
-     * @see \ASN1\Element::isConstructed()
-     * @return bool
-     */
-    public function isConstructed(): bool
-    {
-        return $this->_identifier->isConstructed();
-    }
+	/**
+	 *
+	 * @see \ASN1\Element::isConstructed()
+	 * @return bool
+	 */
+	public function isConstructed(): bool
+	{
+		return $this->_identifier->isConstructed();
+	}
     
-    /**
-     *
-     * @see \ASN1\Element::_encodedContentDER()
-     * @return string
-     */
-    protected function _encodedContentDER(): string
-    {
-        $idx = $this->_offset;
-        $length = Length::expectFromDER($this->_data, $idx);
-        return substr($this->_data, $idx, $length->length());
-    }
+	/**
+	 *
+	 * @see \ASN1\Element::_encodedContentDER()
+	 * @return string
+	 */
+	protected function _encodedContentDER(): string
+	{
+		$idx = $this->_offset;
+		$length = Length::expectFromDER($this->_data, $idx);
+		return substr($this->_data, $idx, $length->length());
+	}
     
-    /**
-     * {@inheritdoc}
-     * @see \ASN1\Type\Tagged\ImplicitTagging::implicit()
-     * @return UnspecifiedType
-     */
-    public function implicit($tag, int $class = Identifier::CLASS_UNIVERSAL): UnspecifiedType
-    {
-        $identifier = $this->_identifier->withClass($class)->withTag($tag);
-        $cls = self::_determineImplClass($identifier);
-        $idx = $this->_offset;
-        $element = $cls::_decodeFromDER($identifier, $this->_data, $idx);
-        return new UnspecifiedType($element);
-    }
+	/**
+	 * {@inheritdoc}
+	 * @see \ASN1\Type\Tagged\ImplicitTagging::implicit()
+	 * @return UnspecifiedType
+	 */
+	public function implicit($tag, int $class = Identifier::CLASS_UNIVERSAL): UnspecifiedType
+	{
+		$identifier = $this->_identifier->withClass($class)->withTag($tag);
+		$cls = self::_determineImplClass($identifier);
+		$idx = $this->_offset;
+		$element = $cls::_decodeFromDER($identifier, $this->_data, $idx);
+		return new UnspecifiedType($element);
+	}
     
-    /**
-     *
-     * @see \ASN1\Type\Tagged\ExplicitTagging::explicit()
-     * @return UnspecifiedType
-     */
-    public function explicit($expectedTag = null): UnspecifiedType
-    {
-        $idx = $this->_offset;
-        Length::expectFromDER($this->_data, $idx);
-        $element = Element::fromDER($this->_data, $idx);
-        if (isset($expectedTag)) {
-            $element->expectType($expectedTag);
-        }
-        return new UnspecifiedType($element);
-    }
+	/**
+	 *
+	 * @see \ASN1\Type\Tagged\ExplicitTagging::explicit()
+	 * @return UnspecifiedType
+	 */
+	public function explicit($expectedTag = null): UnspecifiedType
+	{
+		$idx = $this->_offset;
+		Length::expectFromDER($this->_data, $idx);
+		$element = Element::fromDER($this->_data, $idx);
+		if (isset($expectedTag)) {
+			$element->expectType($expectedTag);
+		}
+		return new UnspecifiedType($element);
+	}
 }

lib/ASN1/Type/PrimitiveType.php

Indentation +9 added lines, -9 removed lines

@@ -9,13 +9,13 @@
  */
 trait PrimitiveType
 {
-    /**
-     *
-     * @see \ASN1\Element::isConstructed()
-     * @return boolean
-     */
-    public function isConstructed(): bool
-    {
-        return false;
-    }
+	/**
+	 *
+	 * @see \ASN1\Element::isConstructed()
+	 * @return boolean
+	 */
+	public function isConstructed(): bool
+	{
+		return false;
+	}
 }

lib/ASN1/Type/Structure.php

Indentation +310 added lines, -310 removed lines

@@ -13,336 +13,336 @@
  * Base class for the constructed types.
  */
 abstract class Structure extends Element implements 
-    \Countable,
-    \IteratorAggregate
+	\Countable,
+	\IteratorAggregate
 {
-    use UniversalClass;
+	use UniversalClass;
     
-    /**
-     * Array of elements in the structure.
-     *
-     * @var Element[] $_elements
-     */
-    protected $_elements;
+	/**
+	 * Array of elements in the structure.
+	 *
+	 * @var Element[] $_elements
+	 */
+	protected $_elements;
     
-    /**
-     * Lookup table for the tagged elements.
-     *
-     * @var TaggedType[]|null $_taggedMap
-     */
-    private $_taggedMap;
+	/**
+	 * Lookup table for the tagged elements.
+	 *
+	 * @var TaggedType[]|null $_taggedMap
+	 */
+	private $_taggedMap;
     
-    /**
-     * Cache variable of elements wrapped into UnspecifiedType objects.
-     *
-     * @var UnspecifiedType[]|null $_unspecifiedTypes
-     */
-    private $_unspecifiedTypes;
+	/**
+	 * Cache variable of elements wrapped into UnspecifiedType objects.
+	 *
+	 * @var UnspecifiedType[]|null $_unspecifiedTypes
+	 */
+	private $_unspecifiedTypes;
     
-    /**
-     * Constructor.
-     *
-     * @param Element[] $elements Any number of elements
-     */
-    public function __construct(Element ...$elements)
-    {
-        $this->_elements = $elements;
-    }
+	/**
+	 * Constructor.
+	 *
+	 * @param Element[] $elements Any number of elements
+	 */
+	public function __construct(Element ...$elements)
+	{
+		$this->_elements = $elements;
+	}
     
-    /**
-     * Clone magic method.
-     */
-    public function __clone()
-    {
-        // clear cache-variables
-        $this->_taggedMap = null;
-        $this->_unspecifiedTypes = null;
-    }
+	/**
+	 * Clone magic method.
+	 */
+	public function __clone()
+	{
+		// clear cache-variables
+		$this->_taggedMap = null;
+		$this->_unspecifiedTypes = null;
+	}
     
-    /**
-     *
-     * @see \ASN1\Element::isConstructed()
-     * @return bool
-     */
-    public function isConstructed(): bool
-    {
-        return true;
-    }
+	/**
+	 *
+	 * @see \ASN1\Element::isConstructed()
+	 * @return bool
+	 */
+	public function isConstructed(): bool
+	{
+		return true;
+	}
     
-    /**
-     *
-     * @see \ASN1\Element::_encodedContentDER()
-     * @return string
-     */
-    protected function _encodedContentDER(): string
-    {
-        $data = "";
-        foreach ($this->_elements as $element) {
-            $data .= $element->toDER();
-        }
-        return $data;
-    }
+	/**
+	 *
+	 * @see \ASN1\Element::_encodedContentDER()
+	 * @return string
+	 */
+	protected function _encodedContentDER(): string
+	{
+		$data = "";
+		foreach ($this->_elements as $element) {
+			$data .= $element->toDER();
+		}
+		return $data;
+	}
     
-    /**
-     *
-     * {@inheritdoc}
-     * @see \ASN1\Element::_decodeFromDER()
-     * @return self
-     */
-    protected static function _decodeFromDER(Identifier $identifier, string $data,
-        int &$offset)
-    {
-        $idx = $offset;
-        if (!$identifier->isConstructed()) {
-            throw new DecodeException(
-                "Structured element must have constructed bit set.");
-        }
-        $length = Length::expectFromDER($data, $idx);
-        $end = $idx + $length->length();
-        $elements = [];
-        while ($idx < $end) {
-            $elements[] = Element::fromDER($data, $idx);
-            // check that element didn't overflow length
-            if ($idx > $end) {
-                throw new DecodeException(
-                    "Structure's content overflows length.");
-            }
-        }
-        $offset = $idx;
-        // return instance by static late binding
-        return new static(...$elements);
-    }
+	/**
+	 *
+	 * {@inheritdoc}
+	 * @see \ASN1\Element::_decodeFromDER()
+	 * @return self
+	 */
+	protected static function _decodeFromDER(Identifier $identifier, string $data,
+		int &$offset)
+	{
+		$idx = $offset;
+		if (!$identifier->isConstructed()) {
+			throw new DecodeException(
+				"Structured element must have constructed bit set.");
+		}
+		$length = Length::expectFromDER($data, $idx);
+		$end = $idx + $length->length();
+		$elements = [];
+		while ($idx < $end) {
+			$elements[] = Element::fromDER($data, $idx);
+			// check that element didn't overflow length
+			if ($idx > $end) {
+				throw new DecodeException(
+					"Structure's content overflows length.");
+			}
+		}
+		$offset = $idx;
+		// return instance by static late binding
+		return new static(...$elements);
+	}
     
-    /**
-     * Explode DER structure to DER encoded components that it contains.
-     *
-     * @param string $data
-     * @throws DecodeException
-     * @return string[]
-     */
-    public static function explodeDER(string $data): array
-    {
-        $offset = 0;
-        $identifier = Identifier::fromDER($data, $offset);
-        if (!$identifier->isConstructed()) {
-            throw new DecodeException("Element is not constructed.");
-        }
-        $length = Length::expectFromDER($data, $offset);
-        $end = $offset + $length->length();
-        $parts = [];
-        while ($offset < $end) {
-            // start of the element
-            $idx = $offset;
-            // skip identifier
-            Identifier::fromDER($data, $offset);
-            // decode element length
-            $length = Length::expectFromDER($data, $offset);
-            // extract der encoding of the element
-            $parts[] = substr($data, $idx, $offset - $idx + $length->length());
-            // update offset over content
-            $offset += $length->length();
-        }
-        return $parts;
-    }
+	/**
+	 * Explode DER structure to DER encoded components that it contains.
+	 *
+	 * @param string $data
+	 * @throws DecodeException
+	 * @return string[]
+	 */
+	public static function explodeDER(string $data): array
+	{
+		$offset = 0;
+		$identifier = Identifier::fromDER($data, $offset);
+		if (!$identifier->isConstructed()) {
+			throw new DecodeException("Element is not constructed.");
+		}
+		$length = Length::expectFromDER($data, $offset);
+		$end = $offset + $length->length();
+		$parts = [];
+		while ($offset < $end) {
+			// start of the element
+			$idx = $offset;
+			// skip identifier
+			Identifier::fromDER($data, $offset);
+			// decode element length
+			$length = Length::expectFromDER($data, $offset);
+			// extract der encoding of the element
+			$parts[] = substr($data, $idx, $offset - $idx + $length->length());
+			// update offset over content
+			$offset += $length->length();
+		}
+		return $parts;
+	}
     
-    /**
-     * Get self with an element at the given index replaced by another.
-     *
-     * @param int $idx Element index
-     * @param Element $el New element to insert into the structure
-     * @throws \OutOfBoundsException
-     * @return self
-     */
-    public function withReplaced(int $idx, Element $el)
-    {
-        if (!isset($this->_elements[$idx])) {
-            throw new \OutOfBoundsException(
-                "Structure doesn't have element at index $idx.");
-        }
-        $obj = clone $this;
-        $obj->_elements[$idx] = $el;
-        return $obj;
-    }
+	/**
+	 * Get self with an element at the given index replaced by another.
+	 *
+	 * @param int $idx Element index
+	 * @param Element $el New element to insert into the structure
+	 * @throws \OutOfBoundsException
+	 * @return self
+	 */
+	public function withReplaced(int $idx, Element $el)
+	{
+		if (!isset($this->_elements[$idx])) {
+			throw new \OutOfBoundsException(
+				"Structure doesn't have element at index $idx.");
+		}
+		$obj = clone $this;
+		$obj->_elements[$idx] = $el;
+		return $obj;
+	}
     
-    /**
-     * Get self with an element inserted before the given index.
-     *
-     * @param int $idx Element index
-     * @param Element $el New element to insert into the structure
-     * @throws \OutOfBoundsException
-     * @return self
-     */
-    public function withInserted(int $idx, Element $el)
-    {
-        if (count($this->_elements) < $idx || $idx < 0) {
-            throw new \OutOfBoundsException("Index $idx is out of bounds.");
-        }
-        $obj = clone $this;
-        array_splice($obj->_elements, $idx, 0, [$el]);
-        return $obj;
-    }
+	/**
+	 * Get self with an element inserted before the given index.
+	 *
+	 * @param int $idx Element index
+	 * @param Element $el New element to insert into the structure
+	 * @throws \OutOfBoundsException
+	 * @return self
+	 */
+	public function withInserted(int $idx, Element $el)
+	{
+		if (count($this->_elements) < $idx || $idx < 0) {
+			throw new \OutOfBoundsException("Index $idx is out of bounds.");
+		}
+		$obj = clone $this;
+		array_splice($obj->_elements, $idx, 0, [$el]);
+		return $obj;
+	}
     
-    /**
-     * Get self with an element appended to the end.
-     *
-     * @param Element $el Element to insert into the structure
-     * @return self
-     */
-    public function withAppended(Element $el)
-    {
-        $obj = clone $this;
-        array_push($obj->_elements, $el);
-        return $obj;
-    }
+	/**
+	 * Get self with an element appended to the end.
+	 *
+	 * @param Element $el Element to insert into the structure
+	 * @return self
+	 */
+	public function withAppended(Element $el)
+	{
+		$obj = clone $this;
+		array_push($obj->_elements, $el);
+		return $obj;
+	}
     
-    /**
-     * Get self with an element prepended in the beginning.
-     *
-     * @param Element $el Element to insert into the structure
-     * @return self
-     */
-    public function withPrepended(Element $el)
-    {
-        $obj = clone $this;
-        array_unshift($obj->_elements, $el);
-        return $obj;
-    }
+	/**
+	 * Get self with an element prepended in the beginning.
+	 *
+	 * @param Element $el Element to insert into the structure
+	 * @return self
+	 */
+	public function withPrepended(Element $el)
+	{
+		$obj = clone $this;
+		array_unshift($obj->_elements, $el);
+		return $obj;
+	}
     
-    /**
-     * Get self with an element at the given index removed.
-     *
-     * @param int $idx Element index
-     * @throws \OutOfBoundsException
-     * @return self
-     */
-    public function withoutElement($idx)
-    {
-        if (!isset($this->_elements[$idx])) {
-            throw new \OutOfBoundsException(
-                "Structure doesn't have element at index $idx.");
-        }
-        $obj = clone $this;
-        array_splice($obj->_elements, $idx, 1);
-        return $obj;
-    }
+	/**
+	 * Get self with an element at the given index removed.
+	 *
+	 * @param int $idx Element index
+	 * @throws \OutOfBoundsException
+	 * @return self
+	 */
+	public function withoutElement($idx)
+	{
+		if (!isset($this->_elements[$idx])) {
+			throw new \OutOfBoundsException(
+				"Structure doesn't have element at index $idx.");
+		}
+		$obj = clone $this;
+		array_splice($obj->_elements, $idx, 1);
+		return $obj;
+	}
     
-    /**
-     * Get elements in the structure.
-     *
-     * @return UnspecifiedType[]
-     */
-    public function elements(): array
-    {
-        if (!isset($this->_unspecifiedTypes)) {
-            $this->_unspecifiedTypes = array_map(
-                function (Element $el) {
-                    return new UnspecifiedType($el);
-                }, $this->_elements);
-        }
-        return $this->_unspecifiedTypes;
-    }
+	/**
+	 * Get elements in the structure.
+	 *
+	 * @return UnspecifiedType[]
+	 */
+	public function elements(): array
+	{
+		if (!isset($this->_unspecifiedTypes)) {
+			$this->_unspecifiedTypes = array_map(
+				function (Element $el) {
+					return new UnspecifiedType($el);
+				}, $this->_elements);
+		}
+		return $this->_unspecifiedTypes;
+	}
     
-    /**
-     * Check whether the structure has an element at the given index, optionally
-     * satisfying given tag expectation.
-     *
-     * @param int $idx Index 0..n
-     * @param int|null $expectedTag Optional type tag expectation
-     * @return bool
-     */
-    public function has(int $idx, $expectedTag = null): bool
-    {
-        if (!isset($this->_elements[$idx])) {
-            return false;
-        }
-        if (isset($expectedTag)) {
-            if (!$this->_elements[$idx]->isType($expectedTag)) {
-                return false;
-            }
-        }
-        return true;
-    }
+	/**
+	 * Check whether the structure has an element at the given index, optionally
+	 * satisfying given tag expectation.
+	 *
+	 * @param int $idx Index 0..n
+	 * @param int|null $expectedTag Optional type tag expectation
+	 * @return bool
+	 */
+	public function has(int $idx, $expectedTag = null): bool
+	{
+		if (!isset($this->_elements[$idx])) {
+			return false;
+		}
+		if (isset($expectedTag)) {
+			if (!$this->_elements[$idx]->isType($expectedTag)) {
+				return false;
+			}
+		}
+		return true;
+	}
     
-    /**
-     * Get the element at the given index, optionally checking that the element
-     * has a given tag.
-     *
-     * NOTE! Expectation checking is deprecated and should be done
-     * with UnspecifiedType.
-     *
-     * @param int $idx Index 0..n
-     * @param int|null $expectedTag Optional type tag expectation
-     * @throws \OutOfBoundsException If element doesn't exists
-     * @throws \UnexpectedValueException If expectation fails
-     * @return UnspecifiedType
-     */
-    public function at(int $idx, $expectedTag = null): UnspecifiedType
-    {
-        if (!isset($this->_elements[$idx])) {
-            throw new \OutOfBoundsException(
-                "Structure doesn't have an element at index $idx.");
-        }
-        $element = $this->_elements[$idx];
-        if (isset($expectedTag)) {
-            $element->expectType($expectedTag);
-        }
-        return new UnspecifiedType($element);
-    }
+	/**
+	 * Get the element at the given index, optionally checking that the element
+	 * has a given tag.
+	 *
+	 * NOTE! Expectation checking is deprecated and should be done
+	 * with UnspecifiedType.
+	 *
+	 * @param int $idx Index 0..n
+	 * @param int|null $expectedTag Optional type tag expectation
+	 * @throws \OutOfBoundsException If element doesn't exists
+	 * @throws \UnexpectedValueException If expectation fails
+	 * @return UnspecifiedType
+	 */
+	public function at(int $idx, $expectedTag = null): UnspecifiedType
+	{
+		if (!isset($this->_elements[$idx])) {
+			throw new \OutOfBoundsException(
+				"Structure doesn't have an element at index $idx.");
+		}
+		$element = $this->_elements[$idx];
+		if (isset($expectedTag)) {
+			$element->expectType($expectedTag);
+		}
+		return new UnspecifiedType($element);
+	}
     
-    /**
-     * Check whether the structure contains a context specific element with a
-     * given tag.
-     *
-     * @param int $tag Tag number
-     * @return boolean
-     */
-    public function hasTagged($tag): bool
-    {
-        // lazily build lookup map
-        if (!isset($this->_taggedMap)) {
-            $this->_taggedMap = [];
-            foreach ($this->_elements as $element) {
-                if ($element->isTagged()) {
-                    $this->_taggedMap[$element->tag()] = $element;
-                }
-            }
-        }
-        return isset($this->_taggedMap[$tag]);
-    }
+	/**
+	 * Check whether the structure contains a context specific element with a
+	 * given tag.
+	 *
+	 * @param int $tag Tag number
+	 * @return boolean
+	 */
+	public function hasTagged($tag): bool
+	{
+		// lazily build lookup map
+		if (!isset($this->_taggedMap)) {
+			$this->_taggedMap = [];
+			foreach ($this->_elements as $element) {
+				if ($element->isTagged()) {
+					$this->_taggedMap[$element->tag()] = $element;
+				}
+			}
+		}
+		return isset($this->_taggedMap[$tag]);
+	}
     
-    /**
-     * Get a context specific element tagged with a given tag.
-     *
-     * @param int $tag
-     * @throws \LogicException If tag doesn't exists
-     * @return TaggedType
-     */
-    public function getTagged($tag): TaggedType
-    {
-        if (!$this->hasTagged($tag)) {
-            throw new \LogicException("No tagged element for tag $tag.");
-        }
-        return $this->_taggedMap[$tag];
-    }
+	/**
+	 * Get a context specific element tagged with a given tag.
+	 *
+	 * @param int $tag
+	 * @throws \LogicException If tag doesn't exists
+	 * @return TaggedType
+	 */
+	public function getTagged($tag): TaggedType
+	{
+		if (!$this->hasTagged($tag)) {
+			throw new \LogicException("No tagged element for tag $tag.");
+		}
+		return $this->_taggedMap[$tag];
+	}
     
-    /**
-     *
-     * @see \Countable::count()
-     * @return int
-     */
-    public function count(): int
-    {
-        return count($this->_elements);
-    }
+	/**
+	 *
+	 * @see \Countable::count()
+	 * @return int
+	 */
+	public function count(): int
+	{
+		return count($this->_elements);
+	}
     
-    /**
-     * Get an iterator for the UnspecifiedElement objects.
-     *
-     * @see \IteratorAggregate::getIterator()
-     * @return \ArrayIterator
-     */
-    public function getIterator(): \ArrayIterator
-    {
-        return new \ArrayIterator($this->elements());
-    }
+	/**
+	 * Get an iterator for the UnspecifiedElement objects.
+	 *
+	 * @see \IteratorAggregate::getIterator()
+	 * @return \ArrayIterator
+	 */
+	public function getIterator(): \ArrayIterator
+	{
+		return new \ArrayIterator($this->elements());
+	}
 }