go.opentelemetry.io/otel v1.37.0: attribute.FLOAT64

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify go.opentelemetry.io/otel/attribute.FLOAT64 in pkg:golang/go.opentelemetry.io/otel@v1.37.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel@v1.37.0
Demonstrate these symbols/APIs:
  - go.opentelemetry.io/otel/attribute.FLOAT64

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:37a392102e0b727b02b306ef948b83b1c4754b48515ee0933ef8fcb8d336918f","contract":["attribute.FLOAT64 is the Type constant representing 64-bit floating point values and has string representation FLOAT64.","attribute.Float64Value creates a Value with Type equal to attribute.FLOAT64.","attribute.Float64 and attribute.Key.Float64 create KeyValues whose Value has Type attribute.FLOAT64.","Value of Type attribute.FLOAT64 returns its underlying float64 through AsFloat64 and formatted string through Emit.","Type switch discriminates attribute.FLOAT64 from other attribute types."],"goal":"verify go.opentelemetry.io/otel/attribute.FLOAT64 in pkg:golang/go.opentelemetry.io/otel@v1.37.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel@v1.37.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/otel/attribute.FLOAT64"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel@v1.37.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel@v1.37.0","symbols":["go.opentelemetry.io/otel/attribute.FLOAT64"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require go.opentelemetry.io/otel v1.37.0

github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
go.opentelemetry.io/otel v1.37.0 h1:9zhNfelUvx0KBfu/gb+ZgeAfAgtWrfHJZcAqFC228wQ=
go.opentelemetry.io/otel v1.37.0/go.mod h1:ehE/umFRLnuLa/vSccNq9oS1ErUlkkK71gMcN34UG8I=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package main

import (
	"fmt"

	"go.opentelemetry.io/otel/attribute"
)

func main() {
	// Demonstrate attribute.FLOAT64 type constant
	targetType := attribute.FLOAT64
	fmt.Printf("Demonstrating attribute type: %s\n", targetType)

	// Create a Float64Value and verify its type matches attribute.FLOAT64
	val := attribute.Float64Value(3.14159)
	if val.Type() == attribute.FLOAT64 {
		fmt.Printf("Float64Value has expected type FLOAT64: %f\n", val.AsFloat64())
	}

	// Create a KeyValue using attribute.Float64 and inspect its Type
	kv := attribute.Float64("measurement.ratio", 0.95)
	if kv.Value.Type() == attribute.FLOAT64 {
		fmt.Printf("KeyValue '%s' carries FLOAT64 type with value: %s\n", kv.Key, kv.Value.Emit())
	}
}

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/otel/attribute.FLOAT64 in pkg:golang/go.opentelemetry.io/otel@v1.37.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel@v1.37.0"
  ],
  "symbols": [
    "go.opentelemetry.io/otel/attribute.FLOAT64"
  ]
}

package main

import (
	"fmt"
	"os"

	"go.opentelemetry.io/otel/attribute"
)

func main() {
	// Assertion 1: attribute.FLOAT64 is the Type constant representing 64-bit floating point values and has string representation FLOAT64.
	if attribute.FLOAT64.String() != "FLOAT64" {
		fmt.Fprintf(os.Stderr, "FAIL: expected attribute.FLOAT64.String() == 'FLOAT64', got '%s'\n", attribute.FLOAT64.String())
		os.Exit(1)
	}
	if attribute.FLOAT64 == attribute.INVALID || attribute.FLOAT64 == attribute.BOOL || attribute.FLOAT64 == attribute.INT64 || attribute.FLOAT64 == attribute.STRING || attribute.FLOAT64 == attribute.FLOAT64SLICE {
		fmt.Fprintf(os.Stderr, "FAIL: attribute.FLOAT64 conflicts with other types\n")
		os.Exit(1)
	}

	// Assertion 2: attribute.Float64Value creates a Value with Type equal to attribute.FLOAT64.
	val := attribute.Float64Value(3.14159)
	if val.Type() != attribute.FLOAT64 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Float64Value type to be attribute.FLOAT64, got %v\n", val.Type())
		os.Exit(1)
	}

	// Assertion 3: attribute.Float64 and attribute.Key.Float64 create KeyValues whose Value has Type attribute.FLOAT64.
	kv := attribute.Float64("metric.temperature", 23.75)
	if kv.Value.Type() != attribute.FLOAT64 {
		fmt.Fprintf(os.Stderr, "FAIL: expected attribute.Float64 Value.Type() to be attribute.FLOAT64, got %v\n", kv.Value.Type())
		os.Exit(1)
	}
	key := attribute.Key("metric.humidity")
	kvFromKey := key.Float64(65.2)
	if kvFromKey.Value.Type() != attribute.FLOAT64 {
		fmt.Fprintf(os.Stderr, "FAIL: expected Key.Float64 Value.Type() to be attribute.FLOAT64, got %v\n", kvFromKey.Value.Type())
		os.Exit(1)
	}

	// Assertion 4: Value of Type attribute.FLOAT64 returns its underlying float64 through AsFloat64 and formatted string through Emit.
	if f := val.AsFloat64(); f != 3.14159 {
		fmt.Fprintf(os.Stderr, "FAIL: expected AsFloat64() == 3.14159, got %v\n", f)
		os.Exit(1)
	}
	if e := val.Emit(); e != "3.14159" {
		fmt.Fprintf(os.Stderr, "FAIL: expected Emit() '3.14159', got '%s'\n", e)
		os.Exit(1)
	}

	// Assertion 5: Type switch discriminates attribute.FLOAT64 from other attribute types.
	classify := func(t attribute.Type) string {
		switch t {
		case attribute.FLOAT64:
			return "matched_float64"
		case attribute.BOOL:
			return "matched_bool"
		case attribute.INT64:
			return "matched_int64"
		case attribute.STRING:
			return "matched_string"
		default:
			return "matched_other"
		}
	}
	if classify(attribute.FLOAT64) != "matched_float64" {
		fmt.Fprintf(os.Stderr, "FAIL: type switch failed to match attribute.FLOAT64\n")
		os.Exit(1)
	}
	if classify(attribute.BOOL) != "matched_bool" {
		fmt.Fprintf(os.Stderr, "FAIL: type switch failed on BOOL\n")
		os.Exit(1)
	}
	if classify(attribute.INT64) != "matched_int64" {
		fmt.Fprintf(os.Stderr, "FAIL: type switch failed on INT64\n")
		os.Exit(1)
	}
	if classify(attribute.STRING) != "matched_string" {
		fmt.Fprintf(os.Stderr, "FAIL: type switch failed on STRING\n")
		os.Exit(1)
	}

	fmt.Println("PASS: all attribute.FLOAT64 contract assertions passed.")
}