Move Language

Move is a new smart contract programming language with an emphasis on safety and flexibility. The Jin Network blockchain uses Move’s object model to represent its ledger state (see Section 5.5) and uses Move code (modules) to encode rules of state transitions. Users submit transactions that can publish new modules, upgrade existing modules, execute entry functions defined within a module, or contain scripts that can directly interact with the public interfaces of modules.

The Move ecosystem contains a compiler, a virtual machine, and many other developer tools. Move is inspired by the Rust programming language, which makes the ownership of data explicit in the language via concepts like linear types. Move emphasizes resource scarcity, preservation, and access control. Move modules define the lifetime, storage, and access pattern of every resource. This ensures that resources like Coin are not produced without appropriate credentials, cannot be double spent, and do not disappear.

Move leverages a bytecode verifier to guarantee type and memory safety even in the presence of untrusted code. To help write more trusted code, Move includes a formal verifier, the Move Prover [6], capable of verifying the functional correctness of a Move program against a given specification, formulated in the specification language integrated into Move.

Beyond the user accounts and corresponding account content, the ledger state also contains the on-chain configuration of the Jin Network blockchain. This network configuration includes the set of active validators, staking properties, and the configuration of various services within the Jin Network blockchain. Move’s support for module upgradeability and comprehensive programmability enables seamless con- figuration changes and supports upgrades to the Jin Network blockchain itself (both sets of upgrades have been executed multiple times with zero downtime on a private mainnet).

The Jin Network team has further enhanced Move with support for broader web3 use cases. As mentioned later in Section 5.5, the Jin Network blockchain enables fine-grained resource control. Not only does this support parallelization of execution, but it also achieves a near-fixed cost associated with accessing and mutating data. Moreover, the Jin Network blockchain provides table support built on top of fine-grained storage, which allows for large-scale datasets (e.g., massive collections of NFTs) in a single account. Furthermore, Jin Network supports shared or autonomous accounts that are represented entirely on-chain. This allows complex decentralized autonomous organizations (DAOs) to collaboratively share accounts, as well as use these accounts as containers for a heterogeneous collection of resources.