The Role of Governance Tokens in Crypto Exchange Voting

The following example shows a simple Solidity contract for governance voting. This contract allows holders of a governance token to cast votes on proposals.

solidity

// SPDX-License-Identifier: MITpragma solidity ^0.8.0;

contract GovernanceVoting {
address public governanceToken;
uint256 public proposalIdCounter;
mapping(uint256 => Proposal) public proposals;
mapping(uint256 => mapping(address => bool)) public votes;

struct Proposal {
uint256 id;
string description;
uint256 voteCount;
bool active;
}

constructor(address _governanceToken) {
governanceToken = _governanceToken;
}

function createProposal(string memory _description) public {
proposalIdCounter++;
proposals[proposalIdCounter] = Proposal(proposalIdCounter, _description, 0, true);
}

function vote(uint256 _proposalId) public {
require(IERC20(governanceToken).balanceOf(msg.sender) > 0, “No governance tokens held”);
require(proposals[_proposalId].active, “Proposal is not active”);
require(!votes[_proposalId][msg.sender], “Already voted”);

proposals[_proposalId].voteCount++;
votes[_proposalId][msg.sender] = true;
}

function endProposal(uint256 _proposalId) public {
proposals[_proposalId].active = false;
}
}

interface IERC20 {
function balanceOf(address account) external view returns (uint256);
}

• Explanation:

  • createProposal: Allows token holders to create proposals.
  • vote: Enables governance token holders to cast votes if they have not already done so.
  • endProposal: Ends a proposal’s voting phase.