Struct json::number::Number

pub struct Number { /* fields omitted */ }

Number representation used inside JsonValue. You can easily convert the Number type into native Rust number types and back, or use the equality operator with another number type.

let foo: Number = 3.14.into();
let bar: f64 = foo.into();

assert_eq!(foo, 3.14);
assert_eq!(bar, 3.14);

More often than not you will deal with JsonValue::Number variant that wraps around this type, instead of using the methods here directly.

Methods

impl Number

pub unsafe fn from_parts_unchecked(
    positive: bool,
    mantissa: u64,
    exponent: i16
) -> Self

Construct a new Number from parts. This can't create a NaN value.

let pi = unsafe { Number::from_parts_unchecked(true, 3141592653589793, -15) };

assert_eq!(pi, 3.141592653589793);

While this method is marked unsafe, it doesn't actually perform any unsafe operations. THe goal of the 'unsafe' is to deter from using this method in favor of its safe equivalent from_parts, at least in context when the associated performance cost is negligible.

pub fn from_parts(positive: bool, mantissa: u64, exponent: i16) -> Self

Construct a new Number from parts, stripping unnecessary trailing zeroes. This can't create a NaN value.

let one = Number::from_parts(true, 1000, -3);
let (positive, mantissa, exponent) = one.as_parts();

assert_eq!(true, positive);
assert_eq!(1, mantissa);
assert_eq!(0, exponent);

pub fn as_parts(&self) -> (bool, u64, i16)

Reverse to from_parts - obtain parts from an existing Number.

let pi = Number::from(3.141592653589793);
let (positive, mantissa, exponent) = pi.as_parts();

assert_eq!(positive, true);
assert_eq!(mantissa, 3141592653589793);
assert_eq!(exponent, -15);

pub fn is_sign_positive(&self) -> bool

pub fn is_zero(&self) -> bool

pub fn is_nan(&self) -> bool

pub fn is_empty(&self) -> bool

Test if the number is NaN or has a zero value.

pub fn as_fixed_point_u64(&self, point: u16) -> Option<u64>

Obtain an integer at a fixed decimal point. This is useful for converting monetary values and doing arithmetic on them without rounding errors introduced by floating point operations.

Will return None if Number is negative or a NaN.

let price_a = Number::from(5.99);
let price_b = Number::from(7);
let price_c = Number::from(10.2);

assert_eq!(price_a.as_fixed_point_u64(2), Some(599));
assert_eq!(price_b.as_fixed_point_u64(2), Some(700));
assert_eq!(price_c.as_fixed_point_u64(2), Some(1020));

pub fn as_fixed_point_i64(&self, point: u16) -> Option<i64>

Analog to as_fixed_point_u64, except returning a signed i64, properly handling negative numbers.

let balance_a = Number::from(-1.49);
let balance_b = Number::from(42);

assert_eq!(balance_a.as_fixed_point_i64(2), Some(-149));
assert_eq!(balance_b.as_fixed_point_i64(2), Some(4200));

Trait Implementations

impl Clone for Number

fn clone(&self) -> Number

Returns a copy 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 Display for Number

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

Formats the value using the given formatter.

impl From<Number> for JsonValue

fn from(val: Number) -> JsonValue

Performs the conversion.

impl From<Number> for f64

fn from(num: Number) -> f64

Performs the conversion.

impl From<Number> for f32

fn from(num: Number) -> f32

Performs the conversion.

impl From<f32> for Number

fn from(float: f32) -> Number

Performs the conversion.

impl From<f64> for Number

fn from(float: f64) -> Number

Performs the conversion.

impl From<i16> for Number

fn from(num: i16) -> Number

Performs the conversion.

impl From<i32> for Number

fn from(num: i32) -> Number

Performs the conversion.

impl From<i64> for Number

fn from(num: i64) -> Number

Performs the conversion.

impl From<i8> for Number

fn from(num: i8) -> Number

Performs the conversion.

impl From<isize> for Number

fn from(num: isize) -> Number

Performs the conversion.

impl From<u16> for Number

fn from(num: u16) -> Number

Performs the conversion.

impl From<u32> for Number

fn from(num: u32) -> Number

Performs the conversion.

impl From<u64> for Number

fn from(num: u64) -> Number

Performs the conversion.

impl From<u8> for Number

fn from(num: u8) -> Number

Performs the conversion.

impl From<usize> for Number

fn from(num: usize) -> Number

Performs the conversion.

impl Neg for Number

type Output = Number

The resulting type after applying the - operator.

fn neg(self) -> Number

Performs the unary - operation.

impl PartialEq<JsonValue> for Number

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for JsonValue

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

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

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for usize

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for u8

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for u16

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for u32

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for u64

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for Number

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for f64

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for f32

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for isize

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for i8

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for i16

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for i32

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<Number> for i64

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<f32> for Number

fn eq(&self, other: &f32) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<f64> for Number

fn eq(&self, other: &f64) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<i16> for Number

fn eq(&self, other: &i16) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<i32> for Number

fn eq(&self, other: &i32) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<i64> for Number

fn eq(&self, other: &i64) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<i8> for Number

fn eq(&self, other: &i8) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<isize> for Number

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<u16> for Number

fn eq(&self, other: &u16) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<u32> for Number

fn eq(&self, other: &u32) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<u64> for Number

fn eq(&self, other: &u64) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<u8> for Number

fn eq(&self, other: &u8) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<usize> for Number

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl TryFrom<Number> for isize

type Error = NumberOutOfScope

The type returned in the event of a conversion error.

fn try_from(num: Number) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<Number> for i8

type Error = NumberOutOfScope

The type returned in the event of a conversion error.

fn try_from(num: Number) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<Number> for i16

type Error = NumberOutOfScope

The type returned in the event of a conversion error.

fn try_from(num: Number) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<Number> for i32

type Error = NumberOutOfScope

The type returned in the event of a conversion error.

fn try_from(num: Number) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<Number> for i64

type Error = NumberOutOfScope

The type returned in the event of a conversion error.

fn try_from(num: Number) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<Number> for usize

type Error = NumberOutOfScope

The type returned in the event of a conversion error.

fn try_from(num: Number) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<Number> for u8

type Error = NumberOutOfScope

The type returned in the event of a conversion error.

fn try_from(num: Number) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<Number> for u16

type Error = NumberOutOfScope

The type returned in the event of a conversion error.

fn try_from(num: Number) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<Number> for u32

type Error = NumberOutOfScope

The type returned in the event of a conversion error.

fn try_from(num: Number) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<Number> for u64

type Error = NumberOutOfScope

The type returned in the event of a conversion error.

fn try_from(num: Number) -> Result<Self, Self::Error>

Performs the conversion.