golang.org/x/text v0.3.4: language.Exact

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 golang.org/x/text/language.Exact in pkg:golang/golang.org/x/text@v0.3.4
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/text@v0.3.4
Demonstrate these symbols/APIs:
  - golang.org/x/text/language.Exact

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:f01ab55ac8477b7cf0d36ec4f8da54e5f9ee9d1b1bd9d01d3b839593572f8e36","contract":["language.Exact is a Confidence constant whose string representation is \"Exact\"","language.Comprehends returns Exact confidence for identical language tags","Tag.Script returns Exact confidence when a script is explicitly specified","Tag.Region returns Exact confidence when a region is explicitly specified","Matcher.Match returns Exact confidence when an exact supported tag matches"],"goal":"verify golang.org/x/text/language.Exact in pkg:golang/golang.org/x/text@v0.3.4","kind":"HOW","packages":["pkg:golang/golang.org/x/text@v0.3.4"],"schemaVersion":1,"symbols":["golang.org/x/text/language.Exact"]},"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/golang.org/x/text@v0.3.4"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/text@v0.3.4","symbols":["golang.org/x/text/language.Exact"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.26.6

require golang.org/x/text v0.3.4

golang.org/x/text v0.3.4 h1:0YWbFKbhXG/wIiuHDSKpS0Iy7FSA+u45VtBMfQcFTTc=
golang.org/x/text v0.3.4/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

package main

import (
	"fmt"

	"golang.org/x/text/language"
)

func main() {
	// Exact confidence represents an exact match or an explicitly specified value.
	fmt.Printf("language.Exact value: %s (%d)\n", language.Exact, language.Exact)

	// Comprehends returns Exact when comparing identical language tags.
	conf := language.Comprehends(language.English, language.English)
	fmt.Printf("Comprehends(English, English): %s (is Exact: %t)\n", conf, conf == language.Exact)

	// Script returns Exact when a script was explicitly specified.
	srLatn := language.Make("sr-Latn")
	script, scriptConf := srLatn.Script()
	fmt.Printf("sr-Latn script: %s, confidence: %s (is Exact: %t)\n", script, scriptConf, scriptConf == language.Exact)

	// Region returns Exact when a region was explicitly specified.
	enUS := language.Make("en-US")
	region, regionConf := enUS.Region()
	fmt.Printf("en-US region: %s, confidence: %s (is Exact: %t)\n", region, regionConf, regionConf == language.Exact)

	// Matcher returns Exact when an exact supported tag matches.
	matcher := language.NewMatcher([]language.Tag{language.English, language.French, language.German})
	tag, _, matchConf := matcher.Match(language.English)
	fmt.Printf("Matcher matched: %s, confidence: %s (is Exact: %t)\n", tag, matchConf, matchConf == language.Exact)
}

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/text/language.Exact in pkg:golang/golang.org/x/text@v0.3.4",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/text@v0.3.4"
  ],
  "symbols": [
    "golang.org/x/text/language.Exact"
  ]
}

package main

import (
	"fmt"
	"os"

	"golang.org/x/text/language"
)

func main() {
	// 1. language.Exact is a Confidence constant whose string representation is "Exact"
	if got := language.Exact.String(); got != "Exact" {
		fmt.Fprintf(os.Stderr, "FAIL: expected 'Exact', got %q\n", got)
		os.Exit(1)
	}

	// 2. language.Comprehends returns Exact confidence for identical language tags
	if conf := language.Comprehends(language.English, language.English); conf != language.Exact {
		fmt.Fprintf(os.Stderr, "FAIL: Comprehends(English, English) expected Exact, got %v\n", conf)
		os.Exit(1)
	}

	// 3. Tag.Script returns Exact confidence when a script is explicitly specified
	srLatn := language.Make("sr-Latn")
	if _, conf := srLatn.Script(); conf != language.Exact {
		fmt.Fprintf(os.Stderr, "FAIL: sr-Latn Script() expected Exact confidence, got %v\n", conf)
		os.Exit(1)
	}

	// 4. Tag.Region returns Exact confidence when a region is explicitly specified
	enUS := language.Make("en-US")
	if _, conf := enUS.Region(); conf != language.Exact {
		fmt.Fprintf(os.Stderr, "FAIL: en-US Region() expected Exact confidence, got %v\n", conf)
		os.Exit(1)
	}

	// 5. Matcher.Match returns Exact confidence when an exact supported tag matches
	matcher := language.NewMatcher([]language.Tag{language.English, language.French, language.German})
	matchedTag, _, matchConf := matcher.Match(language.English)
	if matchConf != language.Exact {
		fmt.Fprintf(os.Stderr, "FAIL: Matcher.Match expected Exact confidence, got %v\n", matchConf)
		os.Exit(1)
	}
	if matchedTag != language.English {
		fmt.Fprintf(os.Stderr, "FAIL: Matcher.Match expected English, got %v\n", matchedTag)
		os.Exit(1)
	}

	fmt.Println("PASS: golang.org/x/text/language.Exact contract passed")
}