Introducing Polylang

What is Polylang?

Polylang is a statically (and strongly typed) smart contract programming language, with syntax and features influenced by languages such as JavaScript and TypeScript, used by Polybase (opens in a new tab) for writing smart contracts¹ whereby proofs can be generated that state transitions follow the contract's rules, and which compiles down to Zero-Knowledge (opens in a new tab) programs that are verified using zk-STARKs.

Zero-Knowledge provides two main benefits:

• Provable computation - proves that the code ran as designed, and therefore the output can be trusted.
• Privacy - the user can prove that they possess certain information without revealing the information itself.

Refer to the page on Zero-Knowledge for more details.

Overview

Using Polylang, you can define contract fields, and add methods (functions associated with the contract) that operate on the data (fields).

An example of a typical smart contract in Polylang is:

contract Person {
    id: string;
    name: string;
    age: number;
 
    // create a new record for this smart contract
    constructor (id: string, name: string, age: number) {
        this.id = id;
        this.name = name;
        this.age = age;
    }
 
    // update the name for this record
    setName(newName: string) {
        this.name = newName;
    }
 
    // update the age for this record
    setAge(newAge: number) {
        this.age = age;
    }
}

The code above defines a smart contract called Person which defines a set of fields associated with Person. In this case, we have three fields:

• the id field which uniquely identifies a "record" of this contract
• a name field for storing the name of the person
• an age field for storing the age of the person

Like other smart contract languages, Polylang allows the updating of a contract's state by calling functions/methods on the contract. In the contract above, we have defined a couple of functions that can update the name and age fields of the contract.

Using Polylang

Polylang is open-source and implemented in Rust. It can be used as a CLI or as a library (crate). Head to the next section to get started with Polylang.

Examples

For full-fledged and runnable examples, please refer to the examples (opens in a new tab) in the Polylang repository.