CodeSampleX

Sample

icu_locale_core 2.3.0

Verified sample for cargo icu_locale_core 2.3.0. The contract ran on rust 1 · linux alpine/x64 · docker and passed: locale! and langid! macros construct…

sha256:3c31cb27180525dbaa5c060df99ab8aca362a01510a262fa9c981782ea0d7909

This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured. How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people. MIT-0

Execution evidence

The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.

Evidence basis
Signed contract pass
Verification receipts
1
Signing keys that built it
1
Declared environment linux · alpine · musl x64 cargo

Verification-run environments

Environment Contract Stages Run
rust 1 · linux alpine/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · cargo@1rust:1-alpine@sha256:a10e64dd139b…
2026-09-19

Case

HOW
Goal
verify pkg:cargo/icu_locale_core@2.3.0
Packages
Created
2026-09-18T16:42:58Z

Contract

  1. locale! and langid! macros construct Locale and LanguageIdentifier at compile time
  2. Locale and LanguageIdentifier parse valid BCP 47 strings and reject malformed input
  3. Subtags can be parsed, constructed with macros, and compared
  4. Locale supports modifying subtag components and formatting back to BCP 47 string
  5. Locale parses and normalizes unicode extensions

Files

  • Cargo.lock
  • Cargo.toml
  • PROMPT.md
  • csx.json
  • spec.json
  • src/lib.rs
  • test/contract.rs

Download the source artifact (tar.gz)

Source

Cargo.lock
# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
version = 4

[[package]]
name = "displaydoc"
version = "0.2.7"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c6232dd377dcc64799954cbd3a9bb882e9cdc1308ccd87b1c098f1fb2eaf82a8"
dependencies = [
 "proc-macro2",
 "quote",
 "syn",
]

[[package]]
name = "icu_locale_core"
version = "2.3.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d56e28588da92eee5c3201a6eff33fabdd49b62269c8938d4ff050ce4d900deb"
dependencies = [
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 "litemap",
 "serde",
 "tinystr",
 "writeable",
]

[[package]]
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version = "0.8.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "47d9d19d1d6efa0109d2f65ff4c85cddd50bd572e5a00127ab10987290bcefae"

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dependencies = [
 "unicode-ident",
]

[[package]]
name = "quote"
version = "1.0.47"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "1fbf4db142a473a8d80c26bbf18454ed458bf8d26c8219c331daecfdbd079001"
dependencies = [
 "proc-macro2",
]

[[package]]
name = "sample-icu-locale-core"
version = "1.0.0"
dependencies = [
 "icu_locale_core",
]

[[package]]
name = "serde"
version = "1.0.229"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "4148590afebada386688f18773da617792bf2ef03ffc1e4cbd2b1d45b023e0ba"
dependencies = [
 "serde_core",
 "serde_derive",
]

[[package]]
name = "serde_core"
version = "1.0.229"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "67dca2c9c51e58a4791a4b1ed58308b39c64224d349a935ab5039aa360942a48"
dependencies = [
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]

[[package]]
name = "serde_derive"
version = "1.0.229"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e7a5d71263a5a7d47b41f6b3f06ba276f10cc18b0931f1799f710578e2309348"
dependencies = [
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]

[[package]]
name = "syn"
version = "3.0.6"
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checksum = "8593e8e72159ed2257d083c7a454a85cbf854f37a0966d8d483aff8c8a3ebcee"
dependencies = [
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 "quote",
 "unicode-ident",
]

[[package]]
name = "tinystr"
version = "0.8.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "b1e27c91459209c2986af3dcf603a5a74a4368754ce37414f59acc971167f643"
dependencies = [
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 "serde_core",
 "zerovec",
]

[[package]]
name = "unicode-ident"
version = "1.0.26"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "d245f478577f809a851594d02313b640fb437e0bb33866753cff937863096954"

[[package]]
name = "writeable"
version = "0.6.4"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "3ad82d2a33cdc9674dc7465672f271e096168fcdbe0f799d9e6db8c5892679dc"

[[package]]
name = "zerofrom"
version = "0.1.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "0ec05a11813ea801ff6d75110ad09cd0824ddba17dfe17128ea0d5f68e6c5272"

[[package]]
name = "zerovec"
version = "0.11.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "bb0464e17806c1d976d5cba29399c7f08e516e279e2ba493f63123b5fca67dd8"
dependencies = [
 "serde",
 "zerofrom",
]
Cargo.toml
[package]
name = "sample-icu-locale-core"
version = "1.0.0"
edition = "2021"
publish = false

[dependencies]
icu_locale_core = { version = "=2.3.0", features = ["alloc"] }

[[bin]]
name = "contract"
path = "test/contract.rs"
PROMPT.md
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 pkg:cargo/icu_locale_core@2.3.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:cargo/icu_locale_core@2.3.0

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.
csx.json
{"case":{"caseId":"case:sha256:69967aca1e32d6be09a870354682454b491f75a9c536e279394875654f4648dc","contract":["locale! and langid! macros construct Locale and LanguageIdentifier at compile time","Locale and LanguageIdentifier parse valid BCP 47 strings and reject malformed input","Subtags can be parsed, constructed with macros, and compared","Locale supports modifying subtag components and formatting back to BCP 47 string","Locale parses and normalizes unicode extensions"],"goal":"verify pkg:cargo/icu_locale_core@2.3.0","kind":"HOW","packages":["pkg:cargo/icu_locale_core@2.3.0"],"schemaVersion":1},"contractCommand":["cargo","run","--offline"],"environment":{"arch":"x64","distro":"alpine","ecosystem":"cargo","libc":"musl","os":"linux","packageManager":"cargo","schemaVersion":1},"license":"MIT-0","packages":["pkg:cargo/icu_locale_core@2.3.0"],"schemaVersion":1,"subject":"pkg:cargo/icu_locale_core@2.3.0","verifierAdapter":"cargo@1"}
spec.json
{
  "schemaVersion": 1,
  "goal": "verify pkg:cargo/icu_locale_core@2.3.0",
  "kind": "HOW",
  "packages": [
    "pkg:cargo/icu_locale_core@2.3.0"
  ]
}
src/lib.rs
//! Clean-room verification sample for icu_locale_core.

pub use icu_locale_core::*;
test/contract.rs
use icu_locale_core::{langid, locale, Locale, LanguageIdentifier, ParseError};
use icu_locale_core::subtags::{language, region, script, variant, Language, Region, Script, Variant};

fn main() {
    // 1. locale! and langid! macros construct Locale and LanguageIdentifier at compile time
    let loc: Locale = locale!("en-US");
    assert_eq!(loc.id.language, language!("en"));
    assert_eq!(loc.id.region, Some(region!("US")));

    let lid: LanguageIdentifier = langid!("zh-Hans-CN");
    assert_eq!(lid.language, language!("zh"));
    assert_eq!(lid.script, Some(script!("Hans")));
    assert_eq!(lid.region, Some(region!("CN")));

    // 2. Locale and LanguageIdentifier parse valid BCP 47 strings and reject malformed input
    let parsed_loc: Locale = "ja-JP".parse().expect("valid locale");
    assert_eq!(parsed_loc.id.language, language!("ja"));
    assert_eq!(parsed_loc.id.region, Some(region!("JP")));

    let parsed_lid = LanguageIdentifier::try_from_str("fr-CA").expect("valid langid");
    assert_eq!(parsed_lid.language, language!("fr"));
    assert_eq!(parsed_lid.region, Some(region!("CA")));

    let invalid: Result<Locale, ParseError> = "not_valid!".parse();
    assert!(invalid.is_err());

    // 3. Subtags can be parsed, constructed with macros, and compared
    let lang: Language = language!("de");
    let reg: Region = "AT".parse().expect("valid region");
    let scr: Script = script!("Latn");
    let var: Variant = variant!("macos");
    assert_eq!(lang.as_str(), "de");
    assert_eq!(reg.as_str(), "AT");
    assert_eq!(scr.as_str(), "Latn");
    assert_eq!(var.as_str(), "macos");

    // 4. Modifying components of a Locale and formatting to string
    let mut modified_loc = locale!("en-US");
    modified_loc.id.region = Some(region!("GB"));
    assert_eq!(modified_loc.to_string(), "en-GB");
    assert_eq!(modified_loc, locale!("en-GB"));

    // 5. Locale parses and normalizes unicode extensions
    let ext_loc: Locale = "en-US-u-ca-hebrew".parse().expect("valid locale with extension");
    assert_eq!(ext_loc.id.language, language!("en"));
    assert_eq!(ext_loc.id.region, Some(region!("US")));
    assert!(ext_loc.normalizing_eq("EN-us-U-CA-Hebrew"));

    println!("All icu_locale_core contract assertions passed successfully.");
}

Origin Seeder

anonymous