Struct Number 

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

An OCPI number: an exact decimal.

Numbers in OCPI are formatted as JSON numbers. Unless mentioned otherwise, numbers use 4 decimals and a sufficiently large amount of digits.

Why not f64

Every price, VAT percentage, energy volume and tax amount in OCPI ends up on an invoice. A binary float cannot represent 0.10 and cannot add a column of cents without drift, so every arithmetic operation in this crate — the whole tariffs engine included — runs on rust_decimal::Decimal. f32/f64 are denied by lint in the modules where money lives, and no public field of any OCPI object in this crate is a float.

The JSON boundary

The spec requires these values to be JSON numbers, not strings. serde_json represents a fractional JSON number as an f64 unless its arbitrary_precision feature is enabled — a feature that changes serde_json::Value globally for every crate in the build, so ocpi-kit does not impose it. The boundary therefore behaves as follows:

• Integral values pass through exactly, as JSON integers.
• Fractional values with at most 15 significant decimal digits — which covers OCPI’s entire domain of prices, energies and percentages with room to spare — pass through exactly, because the shortest decimal that round-trips an f64 is the original decimal.
• Beyond that, a round-trip rounds to the nearest f64. Number::json_round_trips says whether a given value is affected and Validate::validate reports it as ViolationCode::Imprecise, so this can never happen silently.

A peer that sends a number as a JSON string ("0.25") is tolerated on input and parsed exactly; output is always a JSON number.

use ocpi_kit::types::Number;

let price: Number = "0.2500".parse().unwrap();
assert_eq!(serde_json::to_string(&price).unwrap(), "0.25");
let vat: Number = serde_json::from_str("20").unwrap();
assert_eq!(serde_json::to_string(&vat).unwrap(), "20");

Spec: 2.3.0 §types_number_type

Implementations

impl Number

pub const ZERO: Self

Zero.

pub const ONE: Self

One.

pub const fn new(value: Decimal) -> Self

Wraps a Decimal.

pub const fn get(self) -> Decimal

The underlying Decimal.

pub fn scale(self) -> u32

The number of digits after the decimal point.

pub fn round_dp(self, dp: u32) -> Self

Rounds to dp decimal places, half away from zero.

pub fn json_round_trips(self) -> bool

Whether this value survives a JSON round-trip unchanged.

See the type documentation. false only for values with more significant digits than an f64 can carry.

pub fn is_zero(self) -> bool

Whether the value is zero.

pub fn is_negative(self) -> bool

Whether the value is strictly negative.

Trait Implementations

impl Add for Number

type Output = Number

The resulting type after applying the + operator.

fn add(self, rhs: Self) -> Self

Performs the + operation.

impl Clone for Number

fn clone(&self) -> Number

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Number

impl Debug for Number

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

Formats the value using the given formatter.

impl Default for Number

fn default() -> Number

Returns the “default value” for a type.

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

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl Display for Number

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

Formats the value using the given formatter.

impl Div for Number

type Output = Number

The resulting type after applying the / operator.

fn div(self, rhs: Self) -> Self

Performs the / operation.

impl Eq for Number

impl From<Decimal> for Number

fn from(value: Decimal) -> Self

Converts to this type from the input type.

impl From<Number> for Decimal

fn from(value: Number) -> Self

Converts to this type from the input type.

impl From<i8> for Number

fn from(value: i8) -> Self

Converts to this type from the input type.

impl From<i16> for Number

fn from(value: i16) -> Self

Converts to this type from the input type.

impl From<i32> for Number

fn from(value: i32) -> Self

Converts to this type from the input type.

impl From<i64> for Number

fn from(value: i64) -> Self

Converts to this type from the input type.

impl From<u8> for Number

fn from(value: u8) -> Self

Converts to this type from the input type.

impl From<u16> for Number

fn from(value: u16) -> Self

Converts to this type from the input type.

impl From<u32> for Number

fn from(value: u32) -> Self

Converts to this type from the input type.

impl From<u64> for Number

fn from(value: u64) -> Self

Converts to this type from the input type.

impl FromStr for Number

type Err = InvalidNumber

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

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

impl Hash for Number

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 JsonSchema for Number

Available on crate feature schema only.

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

The name of the generated JSON Schema.

fn json_schema(_g: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type.

fn inline_schema() -> bool

Whether JSON Schemas generated for this type should be included directly in parent schemas, rather than being re-used where possible using the $ref keyword.

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

Returns a string that uniquely identifies the schema produced by this type.

impl Mul for Number

type Output = Number

The resulting type after applying the * operator.

fn mul(self, rhs: Self) -> Self

Performs the * operation.

impl Neg for Number

type Output = Number

The resulting type after applying the - operator.

fn neg(self) -> Self

Performs the unary - operation.

impl Ord for Number

fn cmp(&self, other: &Number) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for Number

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Number

fn partial_cmp(&self, other: &Number) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for Number

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Number

impl Sub for Number

type Output = Number

The resulting type after applying the - operator.

fn sub(self, rhs: Self) -> Self

Performs the - operation.

impl Sum for Number

fn sum<I: Iterator<Item = Self>>(iter: I) -> Self

Takes an iterator and generates Self from the elements by “summing up” the items.

impl Validate for Number

fn validate_in(&self, v: &mut Validator)

Appends this value’s violations to v, relative to v’s current position.

fn validate(&self) -> Result<(), Violations>

Validates this value as the root of an object graph.