Struct ROW_ADDR_FIELD

pub struct ROW_ADDR_FIELD { /* private fields */ }

Row address field. This is nullable because its validity bitmap is sometimes used as a selection vector.

Methods from Deref<Target = ArrowField>

pub const LIST_FIELD_DEFAULT_NAME: &'static str = "item"

pub fn metadata(&self) -> &HashMap<String, String>

Returns the immutable reference to the Field’s optional custom metadata.

pub fn name(&self) -> &String

Returns an immutable reference to the Field’s name.

pub fn data_type(&self) -> &DataType

Returns an immutable reference to the Field’s DataType.

pub fn extension_type_name(&self) -> Option<&str>

Returns the extension type name of this Field, if set.

This returns the value of EXTENSION_TYPE_NAME_KEY, if set in Field::metadata. If the key is missing, there is no extension type name and this returns None.

Example

let field = Field::new("", DataType::Null, false);
assert_eq!(field.extension_type_name(), None);

let field = Field::new("", DataType::Null, false).with_metadata(
   [(EXTENSION_TYPE_NAME_KEY.to_owned(), "example".to_owned())]
       .into_iter()
       .collect(),
);
assert_eq!(field.extension_type_name(), Some("example"));

pub fn extension_type_metadata(&self) -> Option<&str>

Returns the extension type metadata of this Field, if set.

This returns the value of EXTENSION_TYPE_METADATA_KEY, if set in Field::metadata. If the key is missing, there is no extension type metadata and this returns None.

Example

let field = Field::new("", DataType::Null, false);
assert_eq!(field.extension_type_metadata(), None);

let field = Field::new("", DataType::Null, false).with_metadata(
   [(EXTENSION_TYPE_METADATA_KEY.to_owned(), "example".to_owned())]
       .into_iter()
       .collect(),
);
assert_eq!(field.extension_type_metadata(), Some("example"));

pub fn try_extension_type<E>(&self) -> Result<E, ArrowError>

where E: ExtensionType,

Returns an instance of the given ExtensionType of this Field, if set in the Field::metadata.

Error

Returns an error if

• this field does not have the name of this extension type (ExtensionType::NAME) in the Field::metadata (mismatch or missing)
• the deserialization of the metadata (ExtensionType::deserialize_metadata) fails
• the construction of the extension type (ExtensionType::try_new) fail (for example when the Field::data_type is not supported by the extension type (ExtensionType::supports_data_type))

pub fn extension_type<E>(&self) -> E

where E: ExtensionType,

Returns an instance of the given ExtensionType of this Field, panics if this Field does not have this extension type.

Panic

This calls Field::try_extension_type and panics when it returns an error.

pub fn is_nullable(&self) -> bool

Indicates whether this Field supports null values.

pub fn dict_id(&self) -> Option<i64>

👎Deprecated since 54.0.0: The ability to preserve dictionary IDs will be removed. With it, all fields related to it.

Returns the dictionary ID, if this is a dictionary type.

pub fn dict_is_ordered(&self) -> Option<bool>

Returns whether this Field’s dictionary is ordered, if this is a dictionary type.

Example

// non dictionaries do not have a dict is ordered flat
let field = Field::new("c1", DataType::Int64, false);
assert_eq!(field.dict_is_ordered(), None);
// by default dictionary is not ordered
let field = Field::new("c1", DataType::Dictionary(Box::new(DataType::Int64), Box::new(DataType::Utf8)), false);
assert_eq!(field.dict_is_ordered(), Some(false));
let field = field.with_dict_is_ordered(true);
assert_eq!(field.dict_is_ordered(), Some(true));

pub fn contains(&self, other: &Field) -> bool

Check to see if self is a superset of other field. Superset is defined as:

• if nullability doesn’t match, self needs to be nullable
• self.metadata is a superset of other.metadata
• all other fields are equal

pub fn size(&self) -> usize

Return size of this instance in bytes.

Includes the size of Self.

Trait Implementations

impl Deref for ROW_ADDR_FIELD

type Target = Field

The resulting type after dereferencing.

fn deref(&self) -> &ArrowField

Dereferences the value.

impl LazyStatic for ROW_ADDR_FIELD