EVM/MoveVM Cheatsheet

Quickly compare Solidity and Move, and understand how the EVM and MoveVM differ in design and execution.

High-Level Overview

Feature	Ethereum	Supra Move
Smart Contracts	Solidity, EVM	Move, MoveVM
Benefits	Mature, wide adoption	Scalability, low latency, Optimal fees
Transaction Fees	Variable, can be high	Lower and more predictable
Account Addresses	160-bit	256-bit
Account Structure	Balance in a single field, uses nonce	Modules and resources, uses sequence number
Data Storage	Patricia Merkle Trees	Global storage with resources and modules
Storage Mindset	Contract-based storage	Account & Resources centric mindset for code and data
Parallelization	Limited due to shared storage space	Enhanced parallel execution due to resource model
Type Safety	Contract types provide basic type safety	Module structs and generics offer robust type safety
Unique Features	Wide ecosystem, EVM compatibility	Native VRF, Automation, Oracle price feeds

Comparing Token Standards

Aspect	Ethereum/Solidity	Supra Move
Token Structure	Each token is its own contract	Every token uses typed Coin with single, reusable contract
Token Standard	Must conform to standards like ERC20; implementations vary	Uniform interface and implementation for all tokens
Balance Storage	Balances stored in contract using mapping structure	Resource-Oriented: Balances stored as resource in user’s account
Transfer Mechanism	Tokens can be transferred without receiver’s permission	Tokens require receiver’s explicit consent for transfer
Safety	Depends on implementation quality	Resources cannot be arbitrarily created, ensuring token integrity

Comparing EVM and Move VM

Aspect	EVM (Ethereum Virtual Machine)	Move VM (Supra Move Virtual Machine)
Data Storage	Data stored in smart contract’s storage space	Data stored across smart contracts, user accounts, and objects
Parallelization	Limited parallel execution due to shared storage	Enhanced parallel execution enabled by flexible split storage
VM and Language Integration	Separate layers for EVM and languages (Solidity)	Seamless integration between VM layer and Move language
Critical Network Operations	Complex implementation of network operations	Critical operations natively implemented in Move
Function Calling	Dynamic dispatch allows arbitrary contract calls	Static dispatch focuses on security and predictable behavior
Type Safety	Contract types provide basic type safety	Module structs and generics offer robust type safety
Transaction Safety	Uses nonces for transaction ordering	Uses sequence numbers for transaction ordering
Object Accessibility	Objects bound to smart contract scope	Guaranteed global accessibility of objects

Module Structure & Initialization

Ethereum (Solidity)


// SPDX-License-Identifier: MITpragma solidity ^0.8.0;
contract MyContract {    address public owner;    uint256 public value;
    constructor(uint256 _initialValue) {        owner = msg.sender;        value = _initialValue;    }
    modifier onlyOwner() {        require(msg.sender == owner, "Not owner");        _;    }}

Supra Move


module my_address::my_contract {    use supra_framework::signer;    use supra_framework::account;    use std::error;
    struct ContractData has key {        owner: address,        value: u64,    }
    const E_NOT_OWNER: u64 = 1;
    // Called once when module is published    fun init_module(account: &signer) {        let owner = signer::address_of(account);        move_to(account, ContractData {            owner,            value: 0,        });    }
    // Manual initialization function    public entry fun initialize(account: &signer, initial_value: u64) {        let addr = signer::address_of(account);        move_to(account, ContractData {            owner: addr,            value: initial_value,        });    }}

Key Differences:

Supra Move: Uses init_module for automatic initialization or explicit initialization functions
Ethereum: Uses constructors that run once during deployment
Supra Move: Resources are stored under user accounts, not contract addresses
Ethereum: State stored in contract storage slots

Functions

Ethereum (Solidity)


contract Functions {    uint256 private _value;
    // Public function (external callable)    function setValue(uint256 newValue) public {        _value = newValue;    }
    // View function (read-only)    function getValue() public view returns (uint256) {        return _value;    }
    // Pure function (no state access)    function add(uint256 a, uint256 b) public pure returns (uint256) {        return a + b;    }
    // Internal function    function _internalHelper() internal pure returns (uint256) {        return 42;    }
    // Payable function    function deposit() public payable {        // Function can receive Ether    }}

Supra Move


module my_address::functions {    use supra_framework::signer;
    struct Storage has key {        value: u64,    }
    // Public entry function (blockchain callable)    public entry fun set_value(account: &signer, new_value: u64) acquires Storage {        let addr = signer::address_of(account);        let storage = borrow_global_mut<Storage>(addr);        storage.value = new_value;    }
    // View function (read-only)    #[view]    public fun get_value(addr: address): u64 acquires Storage {        borrow_global<Storage>(addr).value    }
    // Public function (can be called by other modules)    public fun add(a: u64, b: u64): u64 {        a + b    }
    // Private function (module internal only)    fun internal_helper(): u64 {        42    }
    // Function that can receive coins    public entry fun deposit(account: &signer, amount: u64) {        // Use coin framework for transfers        // coin::transfer<SupraCoin>(account, target, amount);    }}

Key Differences:

Supra Move: Uses #[view] for read-only functions, public entry for blockchain calls
Ethereum: Uses view, pure, public, external modifiers
Supra Move: acquires keyword, declares which resources the function accesses
Ethereum: Automatic state access without declaration

Basic Types

Ethereum (Solidity)


contract BasicTypes {    // Integers    uint8 smallNumber;      // 0 to 255    uint256 bigNumber;      // 0 to 2^256-1    int256 signedNumber;    // -2^255 to 2^255-1
    // Boolean    bool isActive;
    // Address    address userAddress;
    // Bytes    bytes32 hash;    bytes dynamicBytes;
    // String    string text;
    // Arrays    uint256[] dynamicArray;    uint256[5] fixedArray;
    // Mapping    mapping(address => uint256) balances;
    // Struct    struct User {        string name;        uint256 age;    }}

Supra Move


module my_address::basic_types {    use std::string::{Self, String};    use std::vector;    use aptos_std::table::{Self, Table};
    struct BasicTypes has key {        // Integers (unsigned only)        small_number: u8,       // 0 to 255        medium_number: u64,     // 0 to 2^64-1        big_number: u128,       // 0 to 2^128-1        huge_number: u256,      // 0 to 2^256-1
        // Boolean        is_active: bool,
        // Address        user_address: address,
        // Vector (dynamic array)        dynamic_array: vector<u64>,
        // String        text: String,
        // Table (like mapping)        balances: Table<address, u64>,    }
    // Struct    struct User has store, drop {        name: String,        age: u64,    }}

Structs and Resources

Ethereum (Solidity)


contract StructsExample {    struct Token {        string name;        uint256 totalSupply;        mapping(address => uint256) balances;    }
    Token public token;
    constructor() {        token.name = "MyToken";        token.totalSupply = 1000000;    }
    function transfer(address to, uint256 amount) public {        require(token.balances[msg.sender] >= amount, "Insufficient balance");        token.balances[msg.sender] -= amount;        token.balances[to] += amount;    }}

Supra Move


module my_address::token {    use supra_framework::signer;    use aptos_std::table::{Self, Table};    use std::string::String;    use std::error;
    // Resource stored under account    struct Token has key {        name: String,        total_supply: u64,        balances: Table<address, u64>,    }
    const E_INSUFFICIENT_BALANCE: u64 = 1;
    public entry fun initialize(account: &signer, name: String, total_supply: u64) {        move_to(account, Token {            name,            total_supply,            balances: table::new(),        });    }
    public entry fun transfer(        account: &signer,        to: address,        amount: u64    ) acquires Token {        let from = signer::address_of(account);        let token = borrow_global_mut<Token>(@my_address);
        let from_balance = table::borrow_mut(&mut token.balances, from);        assert!(*from_balance >= amount, error::invalid_argument(E_INSUFFICIENT_BALANCE));
        *from_balance = *from_balance - amount;
        if (table::contains(&token.balances, to)) {            let to_balance = table::borrow_mut(&mut token.balances, to);            *to_balance = *to_balance + amount;        } else {            table::add(&mut token.balances, to, amount);        };    }}

Key Differences:

Supra Move: Resources have abilities (key, store, drop, copy)
Ethereum: Structs are simple data containers
Supra Move: Resources ensure linear type safety
Ethereum: No built-in protection against double-spending

Events

Ethereum (Solidity)


contract Events {    event Transfer(        address indexed from,        address indexed to,        uint256 value    );
    event Approval(        address indexed owner,        address indexed spender,        uint256 value    );
    function transfer(address to, uint256 amount) public {        // Transfer logic...
        emit Transfer(msg.sender, to, amount);    }}

Supra Move


module my_address::events {    use supra_framework::event;    use supra_framework::signer;
    #[event]    struct TransferEvent has drop, store {        from: address,        to: address,        value: u64,    }
    #[event]    struct ApprovalEvent has drop, store {        owner: address,        spender: address,        value: u64,    }
    public entry fun transfer(account: &signer, to: address, amount: u64) {        let from = signer::address_of(account);
        // Transfer logic...
        event::emit(TransferEvent {            from,            to,            value: amount,        });    }}

Key Differences:

Supra Move: Events are structs with #[event] attribute
Ethereum: Events are declared with event keyword
Supra Move: Uses event::emit() to emit events
Ethereum: Uses emit keyword
Supra Move: No indexed parameters concept
Ethereum: Supports indexed parameters for filtering

Storage & State Management

Ethereum (Solidity)


contract Storage {    // State variables stored in contract storage    uint256 private _totalSupply;    mapping(address => uint256) private _balances;
    function updateBalance(address user, uint256 amount) internal {        _balances[user] = amount;    }
    function getBalance(address user) public view returns (uint256) {        return _balances[user];    }}

Supra Move


module my_address::storage {    use supra_framework::signer;    use aptos_std::table::{Self, Table};
    struct TokenStorage has key {        total_supply: u64,        balances: Table<address, u64>,    }
    public entry fun initialize(account: &signer) {        move_to(account, TokenStorage {            total_supply: 0,            balances: table::new(),        });    }
    fun update_balance(storage: &mut TokenStorage, user: address, amount: u64) {        if (table::contains(&storage.balances, user)) {            *table::borrow_mut(&mut storage.balances, user) = amount;        } else {            table::add(&mut storage.balances, user, amount);        };    }
    #[view]    public fun get_balance(addr: address, user: address): u64 acquires TokenStorage {        let storage = borrow_global<TokenStorage>(addr);        if (table::contains(&storage.balances, user)) {            *table::borrow(&storage.balances, user)        } else {            0        }    }}

Key Differences:

Supra Move: Resources stored under specific account addresses
Ethereum: State stored in contract’s storage slots
Supra Move: Must explicitly declare resource access with acquires
Ethereum: Automatic state access

Testing

Ethereum (Solidity with Hardhat)


const { expect } = require("chai");
describe("Token", function () {    it("Should transfer tokens correctly", async function () {        const Token = await ethers.getContractFactory("Token");        const token = await Token.deploy();
        await token.transfer(addr1.address, 100);        expect(await token.balanceOf(addr1.address)).to.equal(100);    });});

Supra Move


#[test_only]module my_address::token_tests {    use my_address::token;    use supra_framework::account;    use std::signer;
    #[test(account = @0x123)]    public entry fun test_transfer(account: signer) {        let addr = signer::address_of(&account);        account::create_account_for_test(addr);
        token::initialize(&account, string::utf8(b"Test"), 1000);        token::transfer(&account, @0x456, 100);
        assert!(token::get_balance(addr, @0x456) == 100, 1);    }}

Deployment

Ethereum


# Using Hardhatnpx hardhat compilenpx hardhat run scripts/deploy.js --network mainnet

Supra Move


# Compile and publish modulesupra move tool publish \  --package-dir /path/to/project \  --rpc-url https://rpc-testnet.supra.com

Account Structure & Transaction Model

Ethereum Account Model


// Ethereum accounts have:// - Address (160-bit)// - Balance (single ETH balance)// - Nonce (for transaction ordering)// - Contract code (for contract accounts)// - Storage (key-value store)
contract Example {    mapping(address => uint256) balances;
    function transfer(address to, uint256 amount) public {        require(balances[msg.sender] >= amount);        balances[msg.sender] -= amount;        balances[to] += amount;    }}

Supra Move Account Model


// Supra accounts have:// - Address (256-bit)// - Sequence number (for transaction ordering)// - Resources (typed data structures)// - Modules (code)
module my_address::example {    use supra_framework::coin;    use supra_framework::supra_coin::SupraCoin;
    // Each account can hold resources directly    public entry fun transfer(from: &signer, to: address, amount: u64) {        coin::transfer<SupraCoin>(from, to, amount);    }}

Recap

Feature	Ethereum/Solidity	Supra Move
Type System	Dynamic typing, runtime checks	Static typing, compile-time safety
Resource Management	Manual memory management	Automatic resource lifecycle
Upgrades	Proxy patterns, complex	Module upgrades, simpler
State Storage	Contract storage	Account resources
Safety	Runtime safety	Compile-time + runtime safety
Arrays	Fixed/dynamic arrays	Vectors
Mappings	Built-in mappings	Table data structure
Events	Built-in event system	Struct-based events
Testing	External frameworks	Built-in testing