CodeSampleX

Sample

syn 2.0.119: syn

Verified sample for cargo syn 2.0.119: syn. The contract ran on rust 1 · linux alpine/x64 · docker and passed: syn::parse_str parses a function definition…

sha256:f0879ce958dd1d8340f3fe39fb2cc07e6deaf9715e7534bfe06addf300878f95

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…
2026-09-17

Case

HOW
Goal
verify syn in pkg:cargo/syn@2.0.119
Packages
Symbols
  • syn
Created
2026-09-17T03:02:07Z

Contract

  1. syn::parse_str parses a function definition into an ItemFn with signature and visibility
  2. syn::parse_str parses a struct definition with derive attributes into a DeriveInput
  3. syn::parse_str parses arithmetic binary expressions into an Expr
  4. syn::parse_str parses reference and generic types into a Type
  5. syn::parse_str parses variable let bindings into a Stmt
  6. syn::parse_file parses full Rust source code with multiple items into a File

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 = "proc-macro2"
version = "1.0.107"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "985e7ec9bb745e6ce6535b544d84d6cd6f7ad8bd711c398938ae983b91a766d9"
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-syn"
version = "1.0.0"
dependencies = [
 "syn",
]

[[package]]
name = "syn"
version = "2.0.119"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "872831b642d1a07999a962a351ed35b955ea2cfc8f3862091e2a240a84f17297"
dependencies = [
 "proc-macro2",
 "quote",
 "unicode-ident",
]

[[package]]
name = "unicode-ident"
version = "1.0.25"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ab72a15cf68d77cb0987d3684aa8a45c5ef827e8cb49ee2f30bfd7ba2feb519f"
Cargo.toml
[package]
name = "sample-syn"
version = "1.0.0"
edition = "2021"
publish = false

[dependencies]
syn = { version = "=2.0.119", features = ["full", "extra-traits"] }

[[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 syn in pkg:cargo/syn@2.0.119
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:cargo/syn@2.0.119
Demonstrate these symbols/APIs:
  - syn

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:ccbf6465d2bd45c608e3330a27e53a069f4147ea18177c22a77ef81cc2f1b8eb","contract":["syn::parse_str parses a function definition into an ItemFn with signature and visibility","syn::parse_str parses a struct definition with derive attributes into a DeriveInput","syn::parse_str parses arithmetic binary expressions into an Expr","syn::parse_str parses reference and generic types into a Type","syn::parse_str parses variable let bindings into a Stmt","syn::parse_file parses full Rust source code with multiple items into a File"],"goal":"verify syn in pkg:cargo/syn@2.0.119","kind":"HOW","packages":["pkg:cargo/syn@2.0.119"],"schemaVersion":1,"symbols":["syn"]},"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/syn@2.0.119"],"schemaVersion":1,"subject":"pkg:cargo/syn@2.0.119","symbols":["syn"],"verifierAdapter":"cargo@1"}
spec.json
{
  "schemaVersion": 1,
  "goal": "verify syn in pkg:cargo/syn@2.0.119",
  "kind": "HOW",
  "packages": [
    "pkg:cargo/syn@2.0.119"
  ],
  "symbols": [
    "syn"
  ]
}
src/lib.rs
//! Clean-room verification sample for syn.

pub use syn::*;
test/contract.rs
use syn::{parse_str, BinOp, Data, DeriveInput, Expr, File, ItemFn, Stmt, Type, Visibility};

fn main() {
    // 1. syn::parse_str parses a function definition into an ItemFn with signature and visibility
    let fn_code = "pub fn add(a: i32, b: i32) -> i32 { a + b }";
    let parsed_fn: ItemFn = parse_str(fn_code).expect("failed to parse ItemFn");
    assert_eq!(parsed_fn.sig.ident.to_string(), "add");
    assert_eq!(parsed_fn.sig.inputs.len(), 2);
    assert!(matches!(parsed_fn.vis, Visibility::Public(_)));

    // 2. syn::parse_str parses a struct definition with derive attributes into a DeriveInput
    let struct_code = r#"
        #[derive(Debug, Clone)]
        pub struct Point {
            pub x: f64,
            pub y: f64,
        }
    "#;
    let parsed_struct: DeriveInput = parse_str(struct_code).expect("failed to parse DeriveInput");
    assert_eq!(parsed_struct.ident.to_string(), "Point");
    assert_eq!(parsed_struct.attrs.len(), 1);
    if let Data::Struct(data_struct) = &parsed_struct.data {
        assert_eq!(data_struct.fields.len(), 2);
    } else {
        panic!("expected struct data");
    }

    // 3. syn::parse_str parses arithmetic binary expressions into an Expr
    let expr_code = "a * 2 + b";
    let parsed_expr: Expr = parse_str(expr_code).expect("failed to parse Expr");
    if let Expr::Binary(bin) = &parsed_expr {
        assert!(matches!(bin.op, BinOp::Add(_)));
    } else {
        panic!("expected binary expression");
    }

    // 4. syn::parse_str parses reference and generic types into a Type
    let type_code = "&'a mut Vec<String>";
    let parsed_type: Type = parse_str(type_code).expect("failed to parse Type");
    if let Type::Reference(type_ref) = &parsed_type {
        assert!(type_ref.mutability.is_some());
        assert_eq!(type_ref.lifetime.as_ref().unwrap().ident.to_string(), "a");
    } else {
        panic!("expected reference type");
    }

    // 5. syn::parse_str parses variable let bindings into a Stmt
    let stmt_code = "let x: i32 = 42;";
    let parsed_stmt: Stmt = parse_str(stmt_code).expect("failed to parse Stmt");
    if let Stmt::Local(local) = &parsed_stmt {
        assert!(local.init.is_some());
    } else {
        panic!("expected local let statement");
    }

    // 6. syn::parse_file parses full Rust source code with multiple items into a File
    let file_code = r#"
        use std::collections::HashMap;

        fn helper() -> bool { true }

        struct State {
            count: usize,
        }
    "#;
    let parsed_file: File = syn::parse_file(file_code).expect("failed to parse File");
    assert_eq!(parsed_file.items.len(), 3);

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

Origin Seeder

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