Struct Number 

pub struct Number<'a> { /* private fields */ }

A number literal from a text format.

This is a well-known borrowing extension (see ext) for numbers that text formats parsed as floats (or integers too large for the data model). It holds the text of the literal in the syntax of JSON numbers together with its value as f64. The fallback is the f64, so consumers that do not know about exact numbers are not affected. Consumers that need the exact value (like Decimal and BigInt and the types of rust_decimal, bigdecimal and num-bigint) use the text.

use deser::ext::{Decimal, Number};

let number = Number::parse("0.10").unwrap();
assert_eq!(number.as_str(), "0.10");
assert_eq!(number.value(), 0.1);

The text borrows from the input for formats that support it, extension values of it are created with ExtValue::borrowed_value::<Number> and looked up with ExtValue::downcast_value_ref::<Number>.

Implementations

impl<'a> Number<'a>

pub fn new<T: Into<Cow<'a, str>>>(text: T, value: f64) -> Number<'a>

Creates a number from its text and value.

The text has to follow the syntax of JSON numbers and the value has to be the (possibly approximated) value of the text. This is not checked in release builds. Use parse to validate the text and compute the value.

pub fn parse<T: Into<Cow<'a, str>>>(text: T) -> Result<Number<'a>, Error>

Parses a number from its text.

The text has to follow the syntax of JSON numbers.

pub fn as_str(&self) -> &str

Returns the text of the number.

pub fn value(&self) -> f64

Returns the value of the number as f64.

This might be an approximation of the text.

pub fn is_integer(&self) -> bool

Returns true if the text is an integer (no fraction or exponent).

pub fn into_owned(self) -> Number<'static>

Detaches the number from the data it borrows.

Trait Implementations

impl BorrowedExtension for Number<'static>

type Value<'a> = Number<'a>

The type of the values of this extension.

fn name<'v>(_value: &'v Number<'_>) -> &'v str

Returns the human readable name of the extension type.

fn fallback<'v>(value: &'v Number<'_>) -> Atom<'v>

Lowers the value into the core data model.

fn to_static(value: &Number<'_>) -> Number<'static>

Detaches a value from the data it borrows.

fn shorten<'s, 'l: 's>(value: &'s Number<'l>) -> &'s Number<'s>

Shortens the lifetime of a value.

impl<'a> Clone for Number<'a>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for Number<'a>

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

Formats the value using the given formatter.

impl<'de, 'a> Deserialize<'de> for Number<'a>

Numbers are deserialized from numbers (and number extension values) and strings with the syntax of JSON numbers. The text is always owned.

fn deserialize_atom( slot: &mut Slot<Self>, atom: Atom<'_>, state: &mut State, ) -> Result<(), Error>

Deserializes an atom into the slot.

fn expecting() -> Cow<'static, str>

Returns what the value expects, for error messages.

fn deserialize_into<'out>( out: &'out mut Option<T>, state: &mut State, ) -> SinkHandle<'out, 'de>

Creates a sink that deserializes the value into the given slot.

fn deserialize_borrowed_atom( slot: &mut Slot<T, Self>, atom: Atom<'de>, state: &mut State, ) -> Result<(), Error>

Deserializes an atom that borrows from the data being deserialized into the slot.

fn describe_type(d: &mut dyn Describe)

Describes the Rust shape of the type.

fn initial_value() -> Option<T>

Provides the value of a missing struct field.

fn deserialize_update<'out>( value: &'out mut T, state: &mut State, ) -> SinkHandle<'out, 'de>

Creates a sink that updates an existing value.

impl<'a> Display for Number<'a>

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

Formats the value using the given formatter.

impl<'a> PartialEq for Number<'a>

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

Equality operator ==.

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

Inequality operator !=.

impl<'a> Serialize for Number<'a>

fn serialize<'b>(value: &'b Self, _state: &mut State) -> Result<Emit<'b>, Error>

Serializes the value.

fn finish(value: &T, state: &mut State) -> Result<(), Error>

Invoked after the serialization finished.

fn is_optional(value: &T) -> bool

Checks if the value represents an optional value.

fn describe(value: &T, d: &mut dyn Describe)

Describes the Rust shape of the value.

fn container_shape(value: &T) -> ContainerShape

Returns the shape of the value if it’s a map or sequence.

impl<'a> StructuralPartialEq for Number<'a>