CodeSampleX

Sample

unicode-ident 1.0.24: unicode_ident::is_xid_start

Verified sample for cargo unicode-ident 1.0.24: unicode_ident::is_xid_start. The contract ran on rust 1 · linux alpine/x64 · docker and passed.

sha256:efdb4b85662da43c3c80076d885bb1dd799eca46e2c0ab58e849e1ea319fbf29

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 · 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 unicode_ident::is_xid_start in pkg:cargo/unicode-ident@1.0.24
Packages
Symbols
  • unicode_ident::is_xid_start
Created
2026-09-17T17:22:20Z

Contract

  1. unicode_ident::is_xid_start('a') == true
  2. unicode_ident::is_xid_start('Z') == true
  3. unicode_ident::is_xid_start('α') == true
  4. unicode_ident::is_xid_start('_') == false
  5. unicode_ident::is_xid_start('0') == false
  6. unicode_ident::is_xid_start(' ') == false

Files

  • Cargo.lock
  • Cargo.toml
  • PROMPT.md
  • csx.json
  • spec.json
  • src/main.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 = "unicode-ident"
version = "1.0.24"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"

[[package]]
name = "unicode-ident-sample"
version = "0.1.0"
dependencies = [
 "unicode-ident",
]
Cargo.toml
[package]
name = "unicode-ident-sample"
version = "0.1.0"
edition = "2021"

[dependencies]
unicode-ident = "=1.0.24"

[[test]]
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 unicode_ident::is_xid_start in pkg:cargo/unicode-ident@1.0.24
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:cargo/unicode-ident@1.0.24
Demonstrate these symbols/APIs:
  - unicode_ident::is_xid_start

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:sha256:9cc7c7fbc3fb5663c32b1e825064f10806b37fe735885dd00969cdef09534feb","contract":["unicode_ident::is_xid_start('a') == true","unicode_ident::is_xid_start('Z') == true","unicode_ident::is_xid_start('α') == true","unicode_ident::is_xid_start('_') == false","unicode_ident::is_xid_start('0') == false","unicode_ident::is_xid_start(' ') == false"],"goal":"verify unicode_ident::is_xid_start in pkg:cargo/unicode-ident@1.0.24","kind":"HOW","packages":["pkg:cargo/unicode-ident@1.0.24"],"schemaVersion":1,"symbols":["unicode_ident::is_xid_start"]},"contractCommand":["cargo","test","--offline"],"environment":{"arch":"x64","ecosystem":"cargo","libc":"musl","os":"linux","packageManager":"cargo","schemaVersion":1},"license":"MIT-0","packages":["pkg:cargo/unicode-ident@1.0.24"],"schemaVersion":1,"subject":"pkg:cargo/unicode-ident@1.0.24","symbols":["unicode_ident::is_xid_start"],"verifierAdapter":"cargo@1"}
spec.json
{
  "schemaVersion": 1,
  "goal": "verify unicode_ident::is_xid_start in pkg:cargo/unicode-ident@1.0.24",
  "kind": "HOW",
  "packages": [
    "pkg:cargo/unicode-ident@1.0.24"
  ],
  "symbols": [
    "unicode_ident::is_xid_start"
  ]
}
src/main.rs
use unicode_ident::is_xid_start;

fn main() {
    assert!(is_xid_start('a'));
    assert!(is_xid_start('Z'));
    assert!(is_xid_start('α'));
    assert!(!is_xid_start('_'));
    assert!(!is_xid_start('0'));
    assert!(!is_xid_start(' '));
}
test/contract.rs
use unicode_ident::is_xid_start;

#[test]
fn contract_is_xid_start() {
    assert!(is_xid_start('a'));
    assert!(is_xid_start('Z'));
    assert!(is_xid_start('α'));
    assert!(!is_xid_start('_'));
    assert!(!is_xid_start('0'));
    assert!(!is_xid_start(' '));
}

Origin Seeder

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