[Proposal] Add WithAttribute methods for metric measurement operations with attributes

CHANGELOG.md

@@ -17,6 +17,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - The `Extrema` in `go.opentelemetry.io/otel/sdk/metric/metricdata` is redefined with a generic argument of `[N int64 | float64]`. (#3870)
 - Move No-Op implementation from `go.opentelemetry.io/otel/metric` into its own package `go.opentelemetry.io/otel/metric/noop`. (#3941)
   - `metric.NewNoopMeterProvider` is replaced with `noop.NewMeterProvider`
+- The measurement methods for all instruments in `go.opentelemetry.io/otel/metric/instrument` accept a `"go.opentelemetry.io/otel/attribute".Set` instead of the variadic `"go.opentelemetry.io/otel/attribute".KeyValue`. (#3947)
+- The `Observer` methods in `go.opentelemetry.io/otel/metric` accept a `"go.opentelemetry.io/otel/attribute".Set` instead of the variadic `"go.opentelemetry.io/otel/attribute".KeyValue`. (#3947)
 
 ### Fixed
 

example/prometheus/main.go

@@ -50,25 +50,25 @@ func main() {
 	// Start the prometheus HTTP server and pass the exporter Collector to it
 	go serveMetrics()
 
-	attrs := []attribute.KeyValue{
+	attrs := attribute.NewSet(
 		attribute.Key("A").String("B"),
 		attribute.Key("C").String("D"),
-	}
+	)
 
 	// This is the equivalent of prometheus.NewCounterVec
 	counter, err := meter.Float64Counter("foo", instrument.WithDescription("a simple counter"))
 	if err != nil {
 		log.Fatal(err)
 	}
-	counter.Add(ctx, 5, attrs...)
+	counter.AddWithAttributes(ctx, 5, attrs)
 
 	gauge, err := meter.Float64ObservableGauge("bar", instrument.WithDescription("a fun little gauge"))
 	if err != nil {
 		log.Fatal(err)
 	}
 	_, err = meter.RegisterCallback(func(_ context.Context, o api.Observer) error {
 		n := -10. + rng.Float64()*(90.) // [-10, 100)
-		o.ObserveFloat64(gauge, n, attrs...)
+		o.ObserveFloat64WithAttributes(gauge, n, attrs)
 		return nil
 	}, gauge)
 	if err != nil {
@@ -80,10 +80,10 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	histogram.Record(ctx, 23, attrs...)
-	histogram.Record(ctx, 7, attrs...)
-	histogram.Record(ctx, 101, attrs...)
-	histogram.Record(ctx, 105, attrs...)
+	histogram.RecordWithAttributes(ctx, 23, attrs)
+	histogram.RecordWithAttributes(ctx, 7, attrs)
+	histogram.RecordWithAttributes(ctx, 101, attrs)
+	histogram.RecordWithAttributes(ctx, 105, attrs)
 
 	ctx, _ = signal.NotifyContext(ctx, os.Interrupt)
 	<-ctx.Done()

example/view/main.go

@@ -64,25 +64,25 @@ func main() {
 	// Start the prometheus HTTP server and pass the exporter Collector to it
 	go serveMetrics()
 
-	attrs := []attribute.KeyValue{
+	attrs := attribute.NewSet(
 		attribute.Key("A").String("B"),
 		attribute.Key("C").String("D"),
-	}
+	)
 
 	counter, err := meter.Float64Counter("foo", instrument.WithDescription("a simple counter"))
 	if err != nil {
 		log.Fatal(err)
 	}
-	counter.Add(ctx, 5, attrs...)
+	counter.AddWithAttributes(ctx, 5, attrs)
 
 	histogram, err := meter.Float64Histogram("custom_histogram", instrument.WithDescription("a histogram with custom buckets and rename"))
 	if err != nil {
 		log.Fatal(err)
 	}
-	histogram.Record(ctx, 136, attrs...)
-	histogram.Record(ctx, 64, attrs...)
-	histogram.Record(ctx, 701, attrs...)
-	histogram.Record(ctx, 830, attrs...)
+	histogram.RecordWithAttributes(ctx, 136, attrs)
+	histogram.RecordWithAttributes(ctx, 64, attrs)
+	histogram.RecordWithAttributes(ctx, 701, attrs)
+	histogram.RecordWithAttributes(ctx, 830, attrs)
 
 	ctx, _ = signal.NotifyContext(ctx, os.Interrupt)
 	<-ctx.Done()