add flying tour, contributing

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collin 2020-08-17 20:21:24 -07:00
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README.md
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@ -13,19 +13,25 @@ Leo is a functional, statically-typed programming language built for writing pri
* [2.2a Build from Crates.io](#22a-build-from-cratesio)
* [2.2b Build from Source Code](#22b-build-from-source-code)
* [3. Quick Start](#3-quick-start)
* [3.1 Zero Knowledge in One Line](#31-zero-knowledge-in-one-line)
* [4. Flying Tour](#4-flying-tour)
* [5. License](#5-license)
* [4.1 Functions](#41-functions)
* [4.2 Testing](#42-testing)
* [4.3 Data Types](#43-data-types)
* [4.4 Circuits](#44-circuits)
* [4.5 Imports](#45-imports)
* [5. Contributing](#5-contributing)
* [6. License](#6-license)
## 1. Overview
Welcome to the Leo programming language.
Leo exists to provide a simple high-level language that compiles to a rank one constraint system (R1CS) circuit. With Leo, you can write circuits to support zero-knowledge tokens, private stable coins, and decentralized marketplaces.
Leo exists to provide a simple high-level language that compiles to a rank one constraint system (R1CS) circuit.
With Leo, you can write circuits to support zero-knowledge tokens, private stable coins, and decentralized marketplaces.
The syntax of Leo is influenced by JavaScript, Python, Scala, and Rust with a strong emphasis on readability and ease-of-use.
# 2. Build Guide
## 2. Build Guide
### 2.1 Install Rust
@ -59,7 +65,7 @@ leo
### 2.2b Build from Source Code
Alternatively, you can install snarkOS by building from the source code as follows:
Alternatively, you can install Leo by building from the source code as follows:
```bash
# Download the source code
@ -75,40 +81,131 @@ This will generate an executable under the `./target/release` directory. To run
./target/release/leo
```
# 3. Quick Start
## 3. Quick Start
Use the Leo CLI to create a new project
```bash
# create a new `hello_world` Leo project
leo new hello_world
cd hello_world
```
This creates a directory with the following structure:
```bash
hello_world/
├── Leo.toml # Your program manifest
├── inputs/
│ └── hello_world.in # Your program inputs
└── src/
└── main.leo # Your program file
```
Let's run the project.
## 3.1 Zero Knowledge in one line
```bash
# build & setup & prove & verify
leo run
```
This command will compile the program, generate keys for a trusted setup, fetch inputs, generate a proof and verify it.
The `leo new` command creates a new Leo project with a given name.
The `leo run` command will compile the main program, generate keys for a trusted setup, fetch inputs, generate a proof and verify it.
Congratulations! You've just run your first Leo program.
## 4. Flying Tour
# 4. Flying Tour
The best way to get to know Leo is by writing some code. We will fly through a high level overview of a Leo file.
If you want to gain a deeper understanding of the Leo language, then check out the [developer docs](https://developer.aleo.org/developer/getting_started/overview)
WIP
# 5. License
**Square Root Example**: Let's prove that we know the square root of a number.
**`src/main.leo`**
```rust // change this to leo
function main(a: u32, b: u32) -> bool {
return square_root(a, b)
}
function square_root(a: u32, b: u32) -> bool {
return a * a == b
}
test function test_square_root() {
let a: u32 = 5;
let b: u32 = 25;
let result = square_root(a, b);
console.assert(result == true);
}
```
### 4.1 Functions
The `main` function is the entrypoint of a Leo program.
`leo run` will provide private inputs directly to the function for proving and store the program result in an output file.
The `square_root` function is called by `main` with private inputs `a` and `b` which are both unsigned `u32` integers.
### 4.2 Testing
A naive way to test `square_root` would be to execute `leo run` several times on different inputs and check the output of the program each time.
Luckily, we can write unit tests in Leo using the `test function` syntax.
In `test_square_root` we can sanity check our code without having to load in private inputs from a file every time.
Want to upgrade your test function into an integration test?
In Leo you can add a test context annotation that loads different sets of private inputs to make your test suite even more robust.
The last line of `test_square_root` uses the console function `console.assert`.
This function along with `console.log`, `console.debug`, and `console.error` provide developers with tools that are run without
affecting the underlying constraint system.
### 4.3 Data Types
Leo supports boolean, unsigned integer, signed integer, field, group element, and address data types.
Collections of data types can be created in the form of static arrays and tuples.
### 4.4 Circuits
**Circuits Example**
**`src/main.leo`**
```rust
circuit Point {
x: u32,
y: u32,
static function new() -> Self {
return Self {
x: 0,
y: 0,
}
}
function add() -> u32 {
return self.x + self.y
}
}
function main() {
let mut p = Point::new();
p.x = 4u32;
p.y = 6u32;
let sum = p.add();
console.log("The sum is {}", sum);
}
```
Circuits in leo are similar to structures in other object-oriented languages.
They provide a composite data type that can store primitive values and provide functions for instantiation and computation.
The `static` keyword modifies the `new` function so it can be called without instantiating the circuit.
Leo introduces `Self` and `self` keywords to access circuit member values.
### 4.5 Imports
Imports fetch other circuits and functions and bring them into the current file scope.
Leo supports imports for dependencies that are declared locally or in an imported package.
Importing packages can be accomplished using the `leo add` command in the CLI.
## 5. Contributing
Please see our guidelines in the [developer docs](https://developer.aleo.org/developer/additional_material/contributing)
Thank you for helping make Leo better!
## 6. License
[![License: GPL v3](https://img.shields.io/badge/License-GPLv3-blue.svg)](./LICENSE.md)