Enum DataType 

#[non_exhaustive]
pub enum DataType {
    Any,
    Unknown,
    Boolean,
    Integer,
    Float,
    Decimal {
        precision: Option<u32>,
        scale: Option<i32>,
    },
    String,
    Binary,
    Date,
    Timestamp {
        timezone: Option<String>,
    },
    List(Box<Field>),
    Struct(Vec<Field>),
    Map {
        key: Box<Field>,
        value: Box<Field>,
    },
}

A field’s logical type.

Scalars are the types tabular formats share; List, Struct and Map nest. Any is a type the source declares to accept anything (JSON Schema’s {}); Unknown is one the source did not say or a reader could not tell (an empty column, a type a mapping does not know).

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Any

Accepts any value.

Unknown

Not known.

Boolean

true or false.

Integer

A whole number, of any width or signedness.

Float

A binary floating-point number.

Decimal

A fixed-point decimal, with its precision (total digits) and scale (digits after the point) when the source gives them.

Fields

precision: Option<u32>

Total digits.

scale: Option<i32>

Digits after the decimal point.

String

Text.

Binary

Bytes.

Date

A calendar date.

Timestamp

A date and time, with its time zone when the source gives one.

Fields

timezone: Option<String>

The time zone, as the source writes it (UTC, +01:00).

List(Box<Field>)

A sequence of items, each described by the field.

Struct(Vec<Field>)

Named fields.

Map

Keys to values.

Fields

key: Box<Field>

The key field.

value: Box<Field>

The value field.

Implementations

impl DataType

pub fn list(item: DataType) -> DataType

A list of nullable items, under the conventional name item.

pub fn map(key: DataType, value: DataType) -> DataType

A map from non-null keys to nullable values, under the conventional names key and value.

pub fn timestamp() -> DataType

A timestamp without a time zone.

pub fn decimal() -> DataType

A decimal without a stated precision or scale.

pub fn is_numeric(&self) -> bool

Whether values of this type are numbers (integer, float or decimal).

pub fn is_nested(&self) -> bool

Whether this type nests other fields (list, struct or map).

pub fn children(&self) -> impl Iterator<Item = &Field>

The fields this type nests: a struct’s fields, a list’s item, a map’s key and value. Empty for scalars.

Trait Implementations

impl Clone for DataType

fn clone(&self) -> DataType

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DataType

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

Formats the value using the given formatter.

impl Display for DataType

The lowercase name: integer, decimal(10,2), timestamp[UTC], list<string>, map<string, integer>, struct.

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

Formats the value using the given formatter.

impl Eq for DataType

impl Hash for DataType

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

where __H: Hasher,

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for DataType

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for DataType