Struct NamedMetricBuilder 

pub struct NamedMetricBuilder { /* private fields */ }

The ergonomic Rust surface for declaring a named metric.

All validation happens in NamedMetricBuilder::build — no I/O, no server round trip — so a bad declaration fails at boot in the app, and the transmitted IR is exactly what the server validates again at ingest.

Implementations

impl NamedMetricBuilder

pub fn new( id: impl Into<String>, function: AggregateFunction, argument: Option<&str>, ) -> Result<NamedMetricBuilder, String>

Start a declaration. count() has no argument; every other function requires one — a field path such as "duration", "measurement.value", or "fields.queue_depth".

pub fn filter_eq( self, path: &str, value: impl Into<MetricFilterValue>, ) -> Result<NamedMetricBuilder, String>

Equality filter: path = literal (a Where stage, appended in call order).

pub fn filter_numeric(self, path: &str) -> Result<NamedMetricBuilder, String>

Numeric-only population restriction for path: bakes path >= f64::MIN into the transmitted IR — the same stage shape the legacy metric preset injects. Explicit and visible in query_json; never injected silently by the server. Without it, non-numeric occurrences produce the engine’s canonical row errors.

pub fn group_by(self, path: &str) -> Result<NamedMetricBuilder, String>

Group by a field path. The group alias is assigned positionally at build time (_dim_0, _dim_1, …) — the same convention as the metric preset — because a path like fields.route is not a valid IR identifier. Duplicate paths are rejected.

pub fn time_bucket(self, seconds: u64) -> NamedMetricBuilder

Leading time-bucket group, alias bucket. Also defaults preferred_bucket_seconds to this width when not set explicitly.

pub fn display_name(self, v: impl Into<String>) -> NamedMetricBuilder

pub fn description(self, v: impl Into<String>) -> NamedMetricBuilder

pub fn unit(self, v: impl Into<String>) -> NamedMetricBuilder

pub fn value_type(self, v: MetricValueType) -> NamedMetricBuilder

Overrides the derived default; checked against the same policy the server enforces — an inconsistent override fails build().

pub fn preferred_bucket_seconds(self, v: u64) -> NamedMetricBuilder

pub fn original_dsl(self, v: impl Into<String>) -> NamedMetricBuilder

Provenance only; never executed.

pub fn build(self) -> Result<NamedMetric, String>

Assemble + validate. Fails on unparseable paths (already rejected at each setter), duplicate groups, an inconsistent explicit value_type, or any structural violation of the IR — the document is round-tripped through QueryDocument::from_json_str so alias and structural validation runs here, at boot, not at the server.

Trait Implementations

impl Debug for NamedMetricBuilder

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

Formats the value using the given formatter.