UnkeyedDecodingContainer

A type that provides a view into a decoder's storage and is used to hold the encoded properties of a decodable type sequentially, without keys.

Decoders should provide types conforming to UnkeyedDecodingContainer for their format.

Import
  • import Swift

Instance Variables

var codingPath: [CodingKey] Required

The path of coding keys taken to get to this point in decoding.

Declaration

var count: Int? Required

The number of elements contained within this container.

If the number of elements is unknown, the value is nil.

Declaration

  • var count: Int? { get }
var currentIndex: Int Required

The current decoding index of the container (i.e. the index of the next element to be decoded.) Incremented after every successful decode call.

Declaration

  • var currentIndex: Int { get }
var isAtEnd: Bool Required

A Boolean value indicating whether there are no more elements left to be decoded in the container.

Declaration

  • var isAtEnd: Bool { get }

Instance Methods

mutating func decode(_: Bool.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: Bool.Type) throws -> Bool
mutating func decode(_: Double.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: Double.Type) throws -> Double
mutating func decode(_: Float.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: Float.Type) throws -> Float
mutating func decode(_: Int.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: Int.Type) throws -> Int
mutating func decode(_: Int8.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: Int8.Type) throws -> Int8
mutating func decode(_: Int16.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: Int16.Type) throws -> Int16
mutating func decode(_: Int32.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: Int32.Type) throws -> Int32
mutating func decode(_: Int64.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: Int64.Type) throws -> Int64
mutating func decode(_: String.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: String.Type) throws -> String
mutating func decode(_: UInt.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: UInt.Type) throws -> UInt
mutating func decode(_: UInt8.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: UInt8.Type) throws -> UInt8
mutating func decode(_: UInt16.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: UInt16.Type) throws -> UInt16
mutating func decode(_: UInt32.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: UInt32.Type) throws -> UInt32
mutating func decode(_: UInt64.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode(_ type: UInt64.Type) throws -> UInt64
mutating func decode<T>(_: T.Type) Required

Decodes a value of the given type.

type: The type of value to decode. returns: A value of the requested type, if present for the given key and convertible to the requested type. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type. throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func decode<T>(_ type: T.Type) throws -> T where T : Decodable
mutating func decodeIfPresent(_: Bool.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: Bool.Type) throws -> Bool?
mutating func decodeIfPresent(_: Double.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: Double.Type) throws -> Double?
mutating func decodeIfPresent(_: Float.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: Float.Type) throws -> Float?
mutating func decodeIfPresent(_: Int.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: Int.Type) throws -> Int?
mutating func decodeIfPresent(_: Int8.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: Int8.Type) throws -> Int8?
mutating func decodeIfPresent(_: Int16.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: Int16.Type) throws -> Int16?
mutating func decodeIfPresent(_: Int32.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: Int32.Type) throws -> Int32?
mutating func decodeIfPresent(_: Int64.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: Int64.Type) throws -> Int64?
mutating func decodeIfPresent(_: String.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: String.Type) throws -> String?
mutating func decodeIfPresent(_: UInt.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: UInt.Type) throws -> UInt?
mutating func decodeIfPresent(_: UInt8.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: UInt8.Type) throws -> UInt8?
mutating func decodeIfPresent(_: UInt16.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: UInt16.Type) throws -> UInt16?
mutating func decodeIfPresent(_: UInt32.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: UInt32.Type) throws -> UInt32?
mutating func decodeIfPresent(_: UInt64.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent(_ type: UInt64.Type) throws -> UInt64?
mutating func decodeIfPresent<T>(_: T.Type)

Decodes a value of the given type, if present.

This method returns nil if the container has no elements left to decode, or if the value is null. The difference between these states can be distinguished by checking isAtEnd.

type: The type of value to decode. returns: A decoded value of the requested type, or nil if the value is a null value, or if there are no more elements to decode. throws: DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

Declaration

  • mutating func decodeIfPresent<T>(_ type: T.Type) throws -> T? where T : Decodable
mutating func decodeNil() Required

Decodes a null value.

If the value is not null, does not increment currentIndex.

returns: Whether the encountered value was null. throws: DecodingError.valueNotFound if there are no more values to decode.

Declaration

  • mutating func decodeNil() throws -> Bool
mutating func nestedContainer(keyedBy:) Required

Decodes a nested container keyed by the given type.

type: The key type to use for the container. returns: A keyed decoding container view into self. throws: DecodingError.typeMismatch if the encountered stored value is not a keyed container.

Declaration

mutating func nestedUnkeyedContainer() Required

Decodes an unkeyed nested container.

returns: An unkeyed decoding container view into self. throws: DecodingError.typeMismatch if the encountered stored value is not an unkeyed container.

Declaration

mutating func superDecoder() Required

Decodes a nested container and returns a Decoder instance for decoding super from that container.

returns: A new Decoder to pass to super.init(from:). throws: DecodingError.valueNotFound if the encountered encoded value is null, or of there are no more values to decode.

Declaration

  • mutating func superDecoder() throws -> Decoder

Default Implementations

mutating func decodeIfPresent(_: Bool.Type)

Declaration

  • mutating func decodeIfPresent(_ type: Bool.Type) throws -> Bool?
mutating func decodeIfPresent(_: Double.Type)

Declaration

  • mutating func decodeIfPresent(_ type: Double.Type) throws -> Double?
mutating func decodeIfPresent(_: Float.Type)

Declaration

  • mutating func decodeIfPresent(_ type: Float.Type) throws -> Float?
mutating func decodeIfPresent(_: Int.Type)

Declaration

  • mutating func decodeIfPresent(_ type: Int.Type) throws -> Int?
mutating func decodeIfPresent(_: Int8.Type)

Declaration

  • mutating func decodeIfPresent(_ type: Int8.Type) throws -> Int8?
mutating func decodeIfPresent(_: Int16.Type)

Declaration

  • mutating func decodeIfPresent(_ type: Int16.Type) throws -> Int16?
mutating func decodeIfPresent(_: Int32.Type)

Declaration

  • mutating func decodeIfPresent(_ type: Int32.Type) throws -> Int32?
mutating func decodeIfPresent(_: Int64.Type)

Declaration

  • mutating func decodeIfPresent(_ type: Int64.Type) throws -> Int64?
mutating func decodeIfPresent(_: String.Type)

Declaration

  • mutating func decodeIfPresent(_ type: String.Type) throws -> String?
mutating func decodeIfPresent(_: UInt.Type)

Declaration

  • mutating func decodeIfPresent(_ type: UInt.Type) throws -> UInt?
mutating func decodeIfPresent(_: UInt8.Type)

Declaration

  • mutating func decodeIfPresent(_ type: UInt8.Type) throws -> UInt8?
mutating func decodeIfPresent(_: UInt16.Type)

Declaration

  • mutating func decodeIfPresent(_ type: UInt16.Type) throws -> UInt16?
mutating func decodeIfPresent(_: UInt32.Type)

Declaration

  • mutating func decodeIfPresent(_ type: UInt32.Type) throws -> UInt32?
mutating func decodeIfPresent(_: UInt64.Type)

Declaration

  • mutating func decodeIfPresent(_ type: UInt64.Type) throws -> UInt64?
mutating func decodeIfPresent<T>(_: T.Type)

Declaration

  • mutating func decodeIfPresent<T>(_ type: T.Type) throws -> T? where T : Decodable