# Workspaces

When the code base is getting larger, you might need to work on **multiple crates on the same project**. Rust supports this via Workspaces. You can **build, run tests or generate docs for all crates** at once by running `cargo` commands from the project root.

⭐️ When working on multiple crates same time, there is a higher possibility to having shared dependencies on crates. To prevent downloading and compiling the same dependency multiple times, Rust uses a **shared build directory** under the project root, while running `cargo build` from the project root.

```rust
// # Think we run
mkdir greetings
touch greetings/Cargo.toml
cargo new greetings/lib
cargo new --bin greetings/examples/hello

// # That generates,
.
├── Cargo.toml
├── examples
│  └── hello
│     ├── Cargo.toml
│     └── src
│        └── main.rs
└── lib
   ├── Cargo.toml
   └── src
      └── lib.rs

// # Think we modify following files

// 01. greetings/Cargo.toml
[workspace]
members = [
    "lib",
    "examples/hello"
]

// 02.1 greetings/lib/Cargo.toml
[package]
name = "greetings"
version = "0.1.0"
authors = ["Dumindu Madunuwan"]

[dependencies]

// 02.2 greetings/lib/src/lib.rs
pub fn hello() {
    println!("Hello, world!");
}

// 03.1 greetings/examples/hello/Cargo.toml
[package]
name = "hello"
version = "0.1.0"
authors = ["Dumindu Madunuwan"]

[dependencies]
greetings = { path = "../../lib" }

// 03.2 greetings/examples/hello/src/main.rs
extern crate greetings;

fn main() {
    greetings::hello();
}
```

> 🔎 [rust-lang/rust source folder](https://github.com/rust-lang/rust/tree/master/src) is a good example for a workspace.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://learning-rust.gitbook.io/book/lets-get-it-started/workspaces.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.