golang.org/x/text v0.3.6: language.BritishEnglish

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.BritishEnglish in pkg:golang/golang.org/x/text@v0.3.6
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/text@v0.3.6
Demonstrate these symbols/APIs:
  - golang.org/x/text/language.BritishEnglish
Required runtime conditions:
  - ecosystem: golang
  - language: go
  - packageManager: go@1.26.6
  - runtime: go@1.26.6

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:sha256:6877064501fbb0f8f168fdb6b424dbc0bf456ffee09042bced2a3a07c4919ea6","contract":["language.BritishEnglish has BCP 47 string tag en-GB","language.BritishEnglish base language decomposes to en with exact confidence","language.BritishEnglish region decomposes to GB with exact confidence","language.BritishEnglish parent tag resolves to en-001","language.Make and language.Parse parse en-GB to language.BritishEnglish","language.NewMatcher matches user language preferences to language.BritishEnglish"],"goal":"verify golang.org/x/text/language.BritishEnglish in pkg:golang/golang.org/x/text@v0.3.6","kind":"HOW","packages":["pkg:golang/golang.org/x/text@v0.3.6"],"schemaVersion":1,"symbols":["golang.org/x/text/language.BritishEnglish"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/golang.org/x/text@v0.3.6"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/text@v0.3.6","symbols":["golang.org/x/text/language.BritishEnglish"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.20

require golang.org/x/text v0.3.6

golang.org/x/text v0.3.6 h1:aRYxNxv6iGQlyVaZmk6ZgYEDa+Jg18DxebPSrd6bg1M=
golang.org/x/text v0.3.6/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() {
	tag := language.BritishEnglish
	fmt.Printf("Language Tag: %s\n", tag.String())

	base, _ := tag.Base()
	fmt.Printf("Base Language: %s\n", base.String())

	region, _ := tag.Region()
	fmt.Printf("Region: %s\n", region.String())

	parent := tag.Parent()
	fmt.Printf("Parent Tag: %s\n", parent.String())
}

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/text/language.BritishEnglish in pkg:golang/golang.org/x/text@v0.3.6",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/text@v0.3.6"
  ],
  "symbols": [
    "golang.org/x/text/language.BritishEnglish"
  ],
  "runtimeConditions": {
    "ecosystem": "golang",
    "language": "go",
    "packageManager": "go@1.26.6",
    "runtime": "go@1.26.6"
  }
}

package main

import (
	"fmt"
	"os"

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

func main() {
	// Assertion 1: language.BritishEnglish has BCP 47 string tag "en-GB"
	tag := language.BritishEnglish
	if got := tag.String(); got != "en-GB" {
		fmt.Fprintf(os.Stderr, "assertion 1 failed: tag.String() = %q, want %q\n", got, "en-GB")
		os.Exit(1)
	}

	// Assertion 2: language.BritishEnglish base language decomposes to "en" with exact confidence
	base, confBase := tag.Base()
	if base.String() != "en" {
		fmt.Fprintf(os.Stderr, "assertion 2 failed: base.String() = %q, want %q\n", base.String(), "en")
		os.Exit(1)
	}
	if confBase != language.Exact {
		fmt.Fprintf(os.Stderr, "assertion 2 failed: confBase = %v, want %v\n", confBase, language.Exact)
		os.Exit(1)
	}

	// Assertion 3: language.BritishEnglish region decomposes to "GB" with exact confidence
	region, confRegion := tag.Region()
	if region.String() != "GB" {
		fmt.Fprintf(os.Stderr, "assertion 3 failed: region.String() = %q, want %q\n", region.String(), "GB")
		os.Exit(1)
	}
	if confRegion != language.Exact {
		fmt.Fprintf(os.Stderr, "assertion 3 failed: confRegion = %v, want %v\n", confRegion, language.Exact)
		os.Exit(1)
	}

	// Assertion 4: language.BritishEnglish parent tag resolves to en-001
	parent := tag.Parent()
	if parent.String() != "en-001" {
		fmt.Fprintf(os.Stderr, "assertion 4 failed: parent = %v (%q), want \"en-001\"\n", parent, parent.String())
		os.Exit(1)
	}

	// Assertion 5: language.Make and language.Parse parse "en-GB" to language.BritishEnglish
	parsedMake := language.Make("en-GB")
	if parsedMake != language.BritishEnglish {
		fmt.Fprintf(os.Stderr, "assertion 5 failed: language.Make(\"en-GB\") = %v, want %v\n", parsedMake, language.BritishEnglish)
		os.Exit(1)
	}
	parsedTag, err := language.Parse("en-GB")
	if err != nil {
		fmt.Fprintf(os.Stderr, "assertion 5 failed: language.Parse(\"en-GB\") error: %v\n", err)
		os.Exit(1)
	}
	if parsedTag != language.BritishEnglish {
		fmt.Fprintf(os.Stderr, "assertion 5 failed: parsedTag = %v, want %v\n", parsedTag, language.BritishEnglish)
		os.Exit(1)
	}

	// Assertion 6: language.NewMatcher matches user language preferences to language.BritishEnglish
	matcher := language.NewMatcher([]language.Tag{
		language.BritishEnglish,
		language.German,
	})
	matchedTag, index, _ := matcher.Match(language.Make("en-GB"), language.Make("en"))
	if matchedTag != language.BritishEnglish || index != 0 {
		fmt.Fprintf(os.Stderr, "assertion 6 failed: matcher.Match returned tag=%v index=%d, want BritishEnglish index=0\n", matchedTag, index)
		os.Exit(1)
	}

	fmt.Println("All contract assertions passed.")
}