diff --git a/contracts/ERC20.sol b/contracts/ERC20.sol new file mode 100644 index 000000000..e053284db --- /dev/null +++ b/contracts/ERC20.sol @@ -0,0 +1,12 @@ +contract ERC20 { + function totalSupply() constant returns (uint); + function balanceOf(address who) constant returns (uint); + function allowance(address owner, address spender) constant returns (uint); + + function transfer(address to, uint value) returns (bool ok); + function transferFrom(address from, address to, uint value) returns (bool ok); + function approve(address spender, uint value) returns (bool ok); + + event Transfer(address indexed from, address indexed to, uint value); + event Approval(address indexed owner, address indexed spender, uint value); +} diff --git a/contracts/Token.sol b/contracts/Token.sol new file mode 100644 index 000000000..d672d3097 --- /dev/null +++ b/contracts/Token.sol @@ -0,0 +1,65 @@ +// Source: https://github.com/nexusdev/erc20 +// Flat file implementation of `dappsys/token/base.sol::DSTokenBase` + +// Everything throws instead of returning false on failure. +import 'ERC20.sol'; + +contract Token is ERC20 +{ + mapping( address => uint ) _balances; + mapping( address => mapping( address => uint ) ) _approvals; + uint _supply; + + function Token( uint initial_balance ) { + _balances[msg.sender] = initial_balance; + _supply = initial_balance; + } + function totalSupply() constant returns (uint supply) { + return _supply; + } + function balanceOf( address who ) constant returns (uint value) { + return _balances[who]; + } + function transfer( address to, uint value) returns (bool ok) { + if( _balances[msg.sender] < value ) { + throw; + } + if( !safeToAdd(_balances[to], value) ) { + throw; + } + _balances[msg.sender] -= value; + _balances[to] += value; + Transfer( msg.sender, to, value ); + return true; + } + function transferFrom( address from, address to, uint value) returns (bool ok) { + // if you don't have enough balance, throw + if( _balances[from] < value ) { + throw; + } + // if you don't have approval, throw + if( _approvals[from][msg.sender] < value ) { + throw; + } + if( !safeToAdd(_balances[to], value) ) { + throw; + } + // transfer and return true + _approvals[from][msg.sender] -= value; + _balances[from] -= value; + _balances[to] += value; + Transfer( from, to, value ); + return true; + } + function approve(address spender, uint value) returns (bool ok) { + _approvals[msg.sender][spender] = value; + Approval( msg.sender, spender, value ); + return true; + } + function allowance(address owner, address spender) constant returns (uint _allowance) { + return _approvals[owner][spender]; + } + function safeToAdd(uint a, uint b) internal returns (bool) { + return (a + b >= a); + } +}