Struct Decimal 

pub struct Decimal { /* private fields */ }

Fixed-point decimal: the value is mantissa × 10^(−scale). This mirrors SQL DECIMAL(38, scale) (Postgres/Spark cap precision at 38 digits, which is what an i128 mantissa holds), and is lossless within that range — unlike Float.

Values are normalized on construction: trailing fractional zeros are dropped (1.50 and 1.5 are equal), and 0 always has scale 0. Equality and ordering are therefore by numeric value.

Implementations

impl Decimal

pub fn parse(value: impl AsRef<str>) -> Result<Self>

Parses a decimal numeral such as 3.14, -0.001, or 42. Rejects empty input, malformed numerals, and values exceeding 38 significant digits.

pub fn from_parts(mantissa: i128, scale: u32) -> Self

Builds a decimal from a raw mantissa and scale (mantissa × 10^−scale).

pub fn mantissa(&self) -> i128

pub fn scale(&self) -> u32

pub fn to_canonical_string(&self) -> String

Canonical string form (no superfluous trailing zeros).

pub fn checked_add(&self, other: &Self) -> Option<Self>

pub fn checked_sub(&self, other: &Self) -> Option<Self>

pub fn checked_mul(&self, other: &Self) -> Option<Self>

pub fn to_f64(&self) -> f64

Lossy conversion to f64 (for coercion into float arithmetic).

Trait Implementations

impl Clone for Decimal

fn clone(&self) -> Decimal

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Decimal

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<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Decimal

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

Formats the value using the given formatter.

impl Eq for Decimal

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 Ord for Decimal

fn cmp(&self, other: &Self) -> 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.

impl PartialEq for Decimal

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Decimal

fn partial_cmp(&self, other: &Self) -> 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 Decimal

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

where S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Decimal