Enum MetricSpec 

pub enum MetricSpec {
    Count,
    Sum {
        field: String,
    },
    Avg {
        field: String,
    },
    Min {
        field: String,
    },
    Max {
        field: String,
    },
}

Which metric to compute and (for aggregations) which field to aggregate over.

This is a “tagged enum” — serde uses the “type” JSON key to decide which variant to deserialize into. For example: { "type": "COUNT" } → MetricSpec::Count { "type": "SUM", "field": "price" } → MetricSpec::Sum { field: “price” }

#[serde(tag = "type")] tells serde to use the “type” field as the discriminant.

Variants

Count

Count the number of matching documents. No field needed. JSON: { "type": "COUNT" }

Sum

Sum the numeric values of a field across all matching documents. JSON: { "type": "SUM", "field": "price" }

Fields

field: String

Avg

Compute the arithmetic mean (average) of a field. JSON: { "type": "AVG", "field": "score" }

Fields

field: String

Min

Find the smallest value of a field across all matching documents. JSON: { "type": "MIN", "field": "age" }

Fields

field: String

Max

Find the largest value of a field across all matching documents. JSON: { "type": "MAX", "field": "age" }

Fields

field: String

Trait Implementations

impl Debug for MetricSpec

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for MetricSpec

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.