Enum Value 

#[non_exhaustive]
pub enum Value {
    Null,
    Bool(bool),
    Int(i64),
    Float(f64),
    Text(String),
    Bytes(Bytes),
    List(Vec<Value>),
    Map(Fields),
    Tensor(Tensor),
    Image(Arc<DynamicImage>),
    Custom(Arc<dyn CustomValue>),
}

A value carried by a sample field.

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.

Null

Absent or JSON null.

Bool(bool)

A boolean.

Int(i64)

An integer, e.g. the contents of a .cls file.

Float(f64)

A floating point number.

Text(String)

Text, e.g. the contents of a .txt file.

Bytes(Bytes)

Undecoded (or deliberately raw) file contents.

List(Vec<Value>)

An ordered sequence, e.g. a JSON array or a collated batch column.

Map(Fields)

A string-keyed mapping, e.g. a JSON object or an .npz archive.

Tensor(Tensor)

A dense numeric array, e.g. from .npy or .ten.

Image(Arc<DynamicImage>)

Available on crate feature image only.

A decoded image.

Custom(Arc<dyn CustomValue>)

Anything else a user-supplied decoder produced.

Implementations

impl Value

pub fn custom<T: CustomValue>(value: T) -> Value

Wrap an arbitrary value so it can live inside a sample.

pub fn type_name(&self) -> &'static str

A short type name, useful in error messages.

pub fn as_bytes(&self) -> Option<&Bytes>

Borrow the raw bytes, if this value is undecoded.

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

Borrow the text, if this value is a string.

pub fn as_i64(&self) -> Option<i64>

Read this value as an integer, accepting Int, Bool and whole Floats.

pub fn as_f64(&self) -> Option<f64>

Read this value as a float, accepting Float and Int.

pub fn as_list(&self) -> Option<&[Value]>

Borrow the list elements, if this value is a list.

pub fn as_map(&self) -> Option<&Fields>

Borrow the map, if this value is a map.

pub fn as_tensor(&self) -> Option<&Tensor>

Borrow the tensor, if this value is one.

pub fn as_image(&self) -> Option<&DynamicImage>

Available on crate feature image only.

Borrow the decoded image, if this value is one.

pub fn downcast_ref<T: Any>(&self) -> Option<&T>

Downcast a Value::Custom to a concrete type.

pub fn expect_bytes(&self, key: &str) -> Result<&Bytes>

Like Value::as_bytes but produces a descriptive error.

pub fn to_json(&self) -> Result<Value>

Available on crate feature json only.

Convert to a serde_json::Value where a faithful mapping exists.

Bytes are rejected rather than silently mangled; tensors become nested arrays of numbers; images and custom values are unsupported.

Trait Implementations

impl Clone for Value

fn clone(&self) -> Value

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Value

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

Formats the value using the given formatter.

impl From<&str> for Value

fn from(v: &str) -> Value

Converts to this type from the input type.

impl From<Bytes> for Value

fn from(v: Bytes) -> Value

Converts to this type from the input type.

impl From<IndexMap<String, Value, BuildHasherDefault<Fnv1a>>> for Value

fn from(v: Fields) -> Value

Converts to this type from the input type.

impl From<String> for Value

fn from(v: String) -> Value

Converts to this type from the input type.

impl From<Tensor> for Value

fn from(v: Tensor) -> Value

Converts to this type from the input type.

impl From<Value> for Value

Available on crate feature json only.

fn from(v: Value) -> Value

Converts to this type from the input type.

impl From<Vec<Value>> for Value

fn from(v: Vec<Value>) -> Value

Converts to this type from the input type.

impl From<Vec<u8>> for Value

fn from(v: Vec<u8>) -> Value

Converts to this type from the input type.

impl From<bool> for Value

fn from(v: bool) -> Value

Converts to this type from the input type.

impl From<f32> for Value

fn from(v: f32) -> Value

Converts to this type from the input type.

impl From<f64> for Value

fn from(v: f64) -> Value

Converts to this type from the input type.

impl From<i32> for Value

fn from(v: i32) -> Value

Converts to this type from the input type.

impl From<i64> for Value

fn from(v: i64) -> Value

Converts to this type from the input type.

impl From<usize> for Value

fn from(v: usize) -> Value

Converts to this type from the input type.

impl PartialEq for Value

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

Equality operator ==.

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

Inequality operator !=.