Struct arrow2::datatypes::Field

pub struct Field {
    pub name: String,
    pub data_type: DataType,
    pub nullable: bool,
    pub dict_id: i64,
    pub dict_is_ordered: bool,
    pub metadata: Option<BTreeMap<String, String>>,
}

A logical DataType and its associated metadata per Arrow specification

Fields

name: String

Its name

data_type: DataType

Its logical DataType

nullable: bool

Whether its values can be null or not

dict_id: i64

The dictionary id of this field (currently un-used)

dict_is_ordered: bool

Whether the dictionary’s values are ordered

metadata: Option<BTreeMap<String, String>>

A map of key-value pairs containing additional custom meta data.

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

Creates a new Field with metadata.

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

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

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

Returns the Field’s optional custom metadata.

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

Returns the Field’s name.

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

Returns the Field’s DataType.

pub const fn is_nullable(&self) -> bool

Returns the Field nullability.

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 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 arrow2::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());

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 Display for Field

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

Formats the value using the given formatter.

impl From<&'_ Field> for ArrowJsonField

This is supported on crate feature io_json_integration only.

fn from(field: &Field) -> Self

Performs the conversion.

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

This is supported on crate feature io_ipc only.

Convert an IPC Field to Arrow Field

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

Performs the conversion.

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 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 TryFrom<&'_ Value> for Field

This is supported on crate feature io_json_integration only.

type Error = ArrowError

The type returned in the event of a conversion error.

fn try_from(value: &Value) -> Result<Self>

Performs the conversion.

impl Eq for Field

impl StructuralEq for Field

impl StructuralPartialEq for Field