Struct Decimal 

pub struct Decimal(/* private fields */);

An exact decimal number of arbitrary precision.

This is a well-known extension type (see ext) which holds the decimal as validated text in the syntax of JSON numbers (-12.50, 1e-7). The text is kept as is, so trailing zeros (the scale) are retained. The fallback is the text as string.

When deserializing, decimals, strings, integers and floats are accepted. Number extension values (which text formats like JSON emit for floats) are converted exactly.

use deser::ext::Decimal;

let value: Decimal = "-12.50".parse().unwrap();
assert_eq!(value.as_str(), "-12.50");
let (mantissa, exponent) = value.to_parts();
assert_eq!((mantissa.to_string(), exponent), ("-1250".to_string(), -2));
assert_eq!(Decimal::from_parts(&mantissa, exponent), value);

With the rust_decimal and bigdecimal features the decimal types of these crates serialize as Decimal.

Implementations

impl Decimal

pub fn new<S: Into<String>>(value: S) -> Result<Decimal, Error>

Creates a decimal from its text representation.

The text has to follow the syntax of JSON numbers.

pub fn from_parts(mantissa: &BigInt, exponent: i64) -> Decimal

Creates a decimal from a mantissa and a base 10 exponent.

The value is mantissa * 10^exponent.

pub fn to_parts(&self) -> (BigInt, i64)

Returns the mantissa and the base 10 exponent.

The value is mantissa * 10^exponent. Exponents that do not fit into i64 saturate.

pub fn as_str(&self) -> &str

Returns the text of the decimal.

pub fn into_string(self) -> String

Converts the decimal into its text.

Trait Implementations

impl Clone for Decimal

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Decimal

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Decimal

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 Display for Decimal

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

Formats the value using the given formatter.

impl Eq for Decimal

impl Extension for Decimal

fn name(&self) -> &str

Returns the human readable name of the extension type.

fn fallback(&self) -> Atom<'_>

Lowers the value into the core data model.

impl From<BigInt> for Decimal

fn from(value: BigInt) -> Decimal

Converts to this type from the input type.

impl From<i64> for Decimal

fn from(value: i64) -> Decimal

Converts to this type from the input type.

impl From<u64> for Decimal

fn from(value: u64) -> Decimal

Converts to this type from the input type.

impl FromStr for Decimal

type Err = Error

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Decimal, Error>

Parses a string s to return a value of this type.

impl Hash for Decimal

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, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Decimal

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Decimal

fn serialize<'a>(value: &'a Self, _state: &mut State) -> Result<Emit<'a>, 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 StructuralPartialEq for Decimal

impl TryFrom<f32> for Decimal

fn try_from(value: f32) -> Result<Decimal, Error>

Converts a float with the shortest representation that roundtrips through f32.

type Error = Error

The type returned in the event of a conversion error.

impl TryFrom<f64> for Decimal

fn try_from(value: f64) -> Result<Decimal, Error>

Converts a float with the shortest representation that roundtrips.

type Error = Error

The type returned in the event of a conversion error.