Struct EvidenceLink 

pub struct EvidenceLink {
    pub category: EvidenceCategory,
    pub observation: String,
    pub reference: String,
    pub metric_value: Option<f64>,
    pub metric_unit: Option<String>,
    pub threshold: Option<f64>,
    pub threshold_met: bool,
}

A single verifiable observation in an EvidenceChain.

Each link records:

• what was observed (observation)
• where it can be verified (reference)
• how much was measured (metric_value + metric_unit)
• whether it cleared the decision threshold (threshold, threshold_met)

Build links with the fluent API:

use evidence_chain::{EvidenceLink, EvidenceCategory};

let link = EvidenceLink::new(EvidenceCategory::Value, "Score above cutoff", "record:42")
    .with_metric(0.87, "probability")
    .with_threshold(0.80, true);

assert!(link.threshold_met);
assert_eq!(link.metric_unit.as_deref(), Some("probability"));

Fields

category: EvidenceCategory

Broad category of this observation.

observation: String

Human-readable description of the observed fact.

reference: String

Verifiable pointer to the source: an ID, hash, URL, timestamp, etc.

metric_value: Option<f64>

Numerical measurement of the observation (optional).

metric_unit: Option<String>

Unit of metric_value (e.g. "USD", "blocks", "sat/vB", "ratio").

threshold: Option<f64>

Decision threshold for this criterion (optional).

threshold_met: bool

true if metric_value satisfies threshold, or if no threshold applies.

Implementations

impl EvidenceLink

pub fn new( category: EvidenceCategory, observation: impl Into<String>, reference: impl Into<String>, ) -> Self

Creates a new link with the minimum required fields.

threshold_met defaults to true. Use with_threshold to set it explicitly when a numeric threshold applies.

pub fn with_metric(self, value: f64, unit: impl Into<String>) -> Self

Attaches a numeric measurement to this link.

pub fn with_threshold(self, threshold: f64, met: bool) -> Self

Records the decision threshold and whether it was met.

Trait Implementations

impl Clone for EvidenceLink

fn clone(&self) -> EvidenceLink

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EvidenceLink

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for EvidenceLink

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for EvidenceLink

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.