# Noir
> https://aztec.network/noir/

## Getting Started
> https://noir-lang.org/index.html

- Noir is a domain specific language for creating and verifying proofs. It's design choices are influenced heavily by Rust.
- `nargo` is a command line tool for interacting with Noir programs (e.g. compiling, proving, verifying and more).
- Alternatively, the interactions can also be performed in TypeScript.
- [Install](https://noir-lang.org/getting_started/nargo/installation.html#option-2-compile-from-source):
- Install [Git](https://git-scm.com/book/en/v2/Getting-Started-Installing-Git) and [Rust](https://www.rust-lang.org/tools/install).
- Download Noir's source code from Github by running:
`git clone [e-mail]:noir-lang/noir.git`
- Change directory into the Noir project by running:
`cd noir`
- Option 2.1: Install Executable with WASM backend
Install Nargo by running:
`cargo install --locked --path=crates/nargo --no-default-features --features plonk_bn254_wasm`
- Option 2.2: [Install Executable with Native Backend](https://noir-lang.org/getting_started/nargo/installation.html#option-22-install-executable-with-native-backend)
- Check if the installation was successful by running `nargo --help`

### Notes
___

#### General Commands to Know
> https://noir-lang.org/getting_started/nargo/commands.html

- The `nargo` command (same a `nargo help` / `nargo -h` / `nargo --help`) brings up the menue.
- `nargo new`
- <pkg name>
- nargo check
- Generate `Prover.toml` and Verifier.toml files for specifying prover and verifier.
- nargo excecute
- <witness_name>
- nargo prove
- <proof_name>
- nargo verify
- <proof>
- nargo codegen-verifier
- Generate a Solidity verifier smart contract for the program.
- nargo compile
- <circuit_name>

#### Hello World Program
> https://noir-lang.org/getting_started/hello_world.html

- `nargo new hello_world`
- In production, the common practice is to name the project folder as `circuits` for better identifiability when sitting alongside other folders in the codebase (e.g. `contracts`, `scripts`, `test`).
- Program inputs in Noir are private by default (e.g. `x`), but can be labeled public using the keyword `pub` (e.g. `y`).
- `cd hello_world` & `cargo check`
- Fill in input values for execution in the `Prover.toml` file.
- `constrain x != y;`
- example:

x = "1"
y = "2"

- `nargo prove` <proof_name>
- `nargo verify` <proof_name>