Modules on Aptos

Aptos allows for permissionless publishing of modules within a package as well as upgrading those that have appropriate compatibility policy set.

A module contains several structs and functions, much like Rust.

During package publishing time, a few constraints are maintained:

• Both Structs and public function signatures are published as immutable.
• Only when a module is being published for the first time, and not during an upgrade, will the VM search for and execute an init_module(account: &signer) function. The signer of the account that is publishing the module is passed into the init_module function of the contract. This function must be private and not return any value.