rust-scratchpad

A personal sandbox for experimenting with Rust language features, patterns, and standard library APIs. Uses only the Rust standard library with one exception — the rayon crate for data parallelism.

Project Structure

rust-scratchpad/
├── Cargo.toml           # Package manifest (edition 2024, depends on `rayon`)
├── config.txt           # Sample file used by the file_io example
├── src/
│   └── lib.rs           # Library crate root (currently empty)
└── examples/
    ├── concurrency_and_shared_state.rs
    ├── file_io_and_error_handling.rs
    ├── iterators.rs
    ├── parallelism.rs
    └── secure_file_uploader.rs

Examples

Each example is a standalone binary you can run with cargo run --example <name>.

Example	Topic	Key Concepts
concurrency_and_shared_state	Multi-threading	Arc, Mutex, mpsc channels, thread spawning, error handling across threads
file_io_and_error_handling	File I/O	File / BufReader, custom Result aliases, Box<dyn Error>, line-by-line reading
iterators	Iterator chaining	filter_map, map, filter, collect, directory traversal with read_dir
parallelism	Data parallelism	rayon::par_iter, parallel map, hash computation in parallel
secure_file_uploader	Type-safe state machines	Phantom types, compile-time state transitions (Pending → Validated | Failed), the type-state pattern in Rust

Usage

Run any example with:

cargo run --example <example_name>

For example:

# Demonstrates shared state and message passing between threads
cargo run --example concurrency_and_shared_state

# Reads config.txt and prints each line
cargo run --example file_io_and_error_handling

# Iterator chaining to filter and transform directory entries
cargo run --example iterators

# Computes hashes in parallel using the Rayon crate
cargo run --example parallelism

# Simulates a file upload workflow with compile-time state guarantees
cargo run --example secure_file_uploader

Build everything (library + all examples) without running:

cargo build

About

This is a learning/scratchpad repository. Each example focuses on a specific Rust concept or standard library feature. The src/lib.rs crate is intentionally minimal — the real content lives in the examples.