Struct Numeric 

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

A fixed-scale decimal (Numeric), stored as its decimal string — the wire representation (Daml numerics are transmitted as text to avoid binary-float rounding).

Comparison is numeric, not textual: the ledger echoes values at the type’s full scale (submit "1.5" on a Numeric 10, read back "1.5000000000"), so ==/Ord/Hash compare the canonical decimal value — Numeric("1.5") == Numeric("1.5000000000"). A string that does not parse as a decimal falls back to plain string comparison (and never equals a valid decimal).

LF-JSON: emitted as a string (what the Ledger API produces); on input also accepts a JSON number (the spec allows it — high-precision values should still use the string form, since a JSON number literal is already f64-lossy on the wire).

Validation is asymmetric on purpose. Numeric::parse / str::parse reject anything that is not a decimal literal, so a caller’s typo fails at construction. Values arriving from the ledger — deserialization and the gRPC codec — are taken as-is via Numeric::from_wire: the participant is the authority on the format, and rejecting an unfamiliar-but-harmless spelling would break decoding of a payload the ledger considers valid. A value that is not a decimal literal simply falls out of canonical comparison and never equals a valid one.

Implementations

impl Numeric

pub fn parse(text: impl Into<String>) -> Result<Self, NumericParseError>

Parse a decimal string (-?digits[.digits]; a leading + is accepted), rejecting anything the ledger would reject — use this over raw construction so a typo fails here instead of at command submission.

Errors

Returns NumericParseError when the input is not a decimal literal.

pub fn from_wire(text: impl Into<String>) -> Self

Wrap a decimal string without validating it — for values that came off the wire, where the ledger has already vouched for the format. Prefer Numeric::parse for values a caller typed.

pub fn as_str(&self) -> &str

The decimal string, as stored (the wire form, not canonicalised).

Trait Implementations

impl Clone for Numeric

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 Numeric

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Numeric

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

Deserialize this value from the given Serde deserializer.

impl Display for Numeric

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

Formats the value using the given formatter.

impl Eq for Numeric

impl FromStr for Numeric

type Err = NumericParseError

The associated error which can be returned from parsing.

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

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

impl FromValue for Numeric

fn from_value(value: &Value) -> Result<Self, ValueError>

Decode a wire Value into Self.

impl Hash for Numeric

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 Numeric

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 Numeric

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Numeric

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 Numeric

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

Serialize this value into the given Serde serializer.

impl ToValue for Numeric

fn to_value(&self) -> Value

Encode self as a wire Value.

impl TryFrom<&str> for Numeric

type Error = NumericParseError

The type returned in the event of a conversion error.

fn try_from(text: &str) -> Result<Self, Self::Error>

Performs the conversion.