Struct Decimal 

pub struct Decimal { /* private fields */ }

An exact decimal: mantissa * 10^-scale.

The scale is preserved as given so that 0.10 remains distinguishable from 0.1 for presentation and fingerprinting, while comparisons are numeric.

Implementations

impl Decimal

pub fn from_parts(mantissa: BigInt, scale: u32) -> Decimal

pub fn zero() -> Decimal

pub fn from_bigint(value: BigInt) -> Decimal

pub fn mantissa(&self) -> &BigInt

pub fn scale(&self) -> u32

pub fn parse(source: &str, limits: &Limits) -> Result<Decimal, EngineError>

Parse a locale-independent decimal literal.

Grammar: [+-]? ( digits ('.' digits?)? | '.' digits ) ([eE] [+-]? digits)? No whitespace, no thousands separators, no locale decimal comma.

pub fn parse_default(source: &str) -> Result<Decimal, EngineError>

Parse using conservative default limits. Intended for tests and constants; public entry points must pass explicit limits.

pub fn is_zero(&self) -> bool

pub fn is_negative(&self) -> bool

pub fn is_positive(&self) -> bool

pub fn sign(&self) -> Sign

pub fn neg(&self) -> Decimal

pub fn abs(&self) -> Decimal

pub fn normalized(&self) -> Decimal

Strip trailing fractional zeros. 0.10 becomes 0.1; 100 stays 100.

pub fn canonical_string(&self) -> String

Canonical string used for hashing and cross-representation equality: normalized, plain decimal notation, never exponent notation.

pub fn to_plain_string(&self) -> String

Display string that preserves the declared scale (0.10 prints as 0.10).

pub fn to_bigint_if_integral(&self) -> Option<BigInt>

pub fn to_rational(&self) -> BigRational

pub fn to_f64(&self) -> Option<f64>

Approximate binary64 conversion. Returns None if the value overflows.

pub fn from_f64_display(value: f64) -> Option<Decimal>

Decimal representation of the shortest round-tripping string of value. This is a display conversion, not an exact binary-to-decimal conversion.

pub fn from_f64_exact(value: f64) -> Option<BigRational>

Exact conversion of a finite f64 to a rational (used for comparisons).

pub fn numeric_cmp(&self, other: &Decimal) -> Ordering

Compare two decimals numerically, ignoring scale differences.

pub fn add( &self, other: &Decimal, ctx: &NumericContext, limits: &Limits, ) -> Result<Decimal, EngineError>

pub fn sub( &self, other: &Decimal, ctx: &NumericContext, limits: &Limits, ) -> Result<Decimal, EngineError>

pub fn mul( &self, other: &Decimal, ctx: &NumericContext, limits: &Limits, ) -> Result<Decimal, EngineError>

pub fn div( &self, other: &Decimal, ctx: &NumericContext, limits: &Limits, ) -> Result<(Decimal, bool), EngineError>

Divide under the declared context. Returns (value, inexact).

When the quotient terminates it is returned exactly with trailing zeros stripped. Otherwise the quotient is rounded to ctx.precision significant digits and inexact is true.

pub fn round_to(&self, scale: u32, mode: RoundingMode) -> Decimal

Round to a fixed number of fractional digits.

pub fn round_significant(&self, digits: u32, mode: RoundingMode) -> Decimal

Round to a fixed number of significant digits.

pub fn round_to_scale(&self, target_scale: i64, mode: RoundingMode) -> Decimal

Round to a (possibly negative) decimal scale.

pub fn floor(&self) -> Decimal

pub fn ceil(&self) -> Decimal

pub fn trunc(&self) -> Decimal

pub fn sqrt_exact(&self) -> Option<Decimal>

Exact square root when the decimal has an exact decimal square root.

pub fn pow_u32( &self, exponent: u32, ctx: &NumericContext, limits: &Limits, ) -> Result<Decimal, EngineError>

Integer power. Negative exponents are handled by the caller (division).

pub fn from_rational( value: &BigRational, ctx: &NumericContext, limits: &Limits, ) -> Result<(Decimal, bool), EngineError>

Exact conversion from a rational, or a rounded conversion when allowed.

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 Debug for Decimal

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

Formats the value using the given formatter.

impl Display for Decimal

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

Formats the value using the given formatter.

impl Eq for Decimal

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.

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 Decimal

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

Equality operator ==.

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

Inequality operator !=.

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.