Struct arrow::datatypes::Field

pub struct Field { /* private fields */ }

Contains the meta-data for a single relative type.

The Schema object is an ordered collection of Field objects.

Implementations

impl Field

pub fn new(name: &str, data_type: DataType, nullable: bool) -> Self

Creates a new field

pub fn new_dict(
    name: &str,
    data_type: DataType,
    nullable: bool,
    dict_id: i64,
    dict_is_ordered: bool
) -> Self

Creates a new field

pub fn set_metadata(&mut self, metadata: Option<BTreeMap<String, String>>)

Sets the Field’s optional custom metadata. The metadata is set as None for empty map.

pub fn with_metadata(self, metadata: Option<BTreeMap<String, String>>) -> Self

Sets the metadata of this Field to be metadata and returns self

pub const fn metadata(&self) -> Option<&BTreeMap<String, String>>

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

pub const fn name(&self) -> &String

Returns an immutable reference to the Field’s name.

pub const fn data_type(&self) -> &DataType

Returns an immutable reference to the Field’s data-type.

pub const fn is_nullable(&self) -> bool

Indicates whether this Field supports null values.

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

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

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

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

pub fn from(json: &Value) -> Result<Self>

Parse a Field definition from a JSON representation.

pub fn to_json(&self) -> Value

Generate a JSON representation of the Field.

pub fn try_merge(&mut self, from: &Field) -> Result<()>

Merge field into self if it is compatible. Struct will be merged recursively. NOTE: self may be updated to unexpected state in case of merge failure.

Example:

use arrow::datatypes::*;

let mut field = Field::new("c1", DataType::Int64, false);
assert!(field.try_merge(&Field::new("c1", DataType::Int64, true)).is_ok());
assert!(field.is_nullable());

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

Trait Implementations

impl Clone for Field

fn clone(&self) -> Field

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Field

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Field

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
    __D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl Display for Field

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<&'_ Field> for ArrowJsonField

fn from(field: &Field) -> Self

Converts to this type from the input type.

impl<'a> From<Field<'a>> for Field

Convert an IPC Field to Arrow Field

fn from(field: Field<'_>) -> Field

Converts to this type from the input type.

impl Hash for Field

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl Ord for Field

fn cmp(&self, other: &Field) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<Field> for Field

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl PartialOrd<Field> for Field

fn partial_cmp(&self, other: &Field) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for Field

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error> where
    __S: Serializer, 

Serialize this value into the given Serde serializer.

impl TryFrom<&'_ FFI_ArrowSchema> for Field

type Error = ArrowError

The type returned in the event of a conversion error.

fn try_from(c_schema: &FFI_ArrowSchema) -> Result<Self>

Performs the conversion.

impl TryFrom<&'_ Field> for FFI_ArrowSchema

type Error = ArrowError

The type returned in the event of a conversion error.

fn try_from(field: &Field) -> Result<Self>

Performs the conversion.

impl TryFrom<Field> for FFI_ArrowSchema

type Error = ArrowError

The type returned in the event of a conversion error.

fn try_from(field: Field) -> Result<Self>

Performs the conversion.

impl Eq for Field

impl StructuralEq for Field

impl StructuralPartialEq for Field