ERC23 tokens

ETC23_tokens.sol

pragma solidity ^0.4.9;

contract Owned {
    function owned() { owner = msg.sender; }
    address owner;
    modifier onlyOwner {
        if (msg.sender != owner)
            throw;
        _;
    }
}

/*
 * ERC20 interface
 * see https://github.com/ethereum/EIPs/issues/20
 */
 
 /*
 * Math operations with safety checks
 */
contract SafeMath {
  function safeMul(uint a, uint b) internal returns (uint) {
    uint c = a * b;
    assert(a == 0 || c / a == b);
    return c;
  }

  function safeDiv(uint a, uint b) internal returns (uint) {
    assert(b > 0);
    uint c = a / b;
    assert(a == b * c + a % b);
    return c;
  }

  function safeSub(uint a, uint b) internal returns (uint) {
    assert(b <= a);
    return a - b;
  }

  function safeAdd(uint a, uint b) internal returns (uint) {
    uint c = a + b;
    assert(c>=a && c>=b);
    return c;
  }

  function max64(uint64 a, uint64 b) internal constant returns (uint64) {
    return a >= b ? a : b;
  }

  function min64(uint64 a, uint64 b) internal constant returns (uint64) {
    return a < b ? a : b;
  }

  function max256(uint256 a, uint256 b) internal constant returns (uint256) {
    return a >= b ? a : b;
  }

  function min256(uint256 a, uint256 b) internal constant returns (uint256) {
    return a < b ? a : b;
  }

  function assert(bool assertion) internal {
    if (!assertion) {
      throw;
    }
  }
}

contract ERC20 {
  uint public totalSupply;
  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);
}

 /*
 * Contract that is working with ERC23 tokens
 * it will take only specified tokents and prevent accident token transfers from another ERC23 contracts
 * like every contract is throwing accident ether transactions
 */
 
 contract contractReciever is Owned{
     
    //supported token contracts are stored here
    mapping (address => bool) supportedTokens;
    
    //contract creator can add supported tokens
    function addToken(address _token) onlyOwner{
        supportedTokens[_token]=true;
    }
    
    function fallbackToken(address _from, uint _value){
    
        if(supportedTokens[msg.sender])
        {
            //on token transfer handler code here
        }
        //throw any accident transfers of not supported tokens
        else{ throw; }
    }
 }


 /*
 * ERC23 token by Dexaran
 *
 * https://github.com/... 
 */
 
contract StandardToken is ERC20, SafeMath {

  mapping(address => uint) balances;
  mapping (address => mapping (address => uint)) allowed;

  function transfer(address _to, uint _value) returns (bool success) {
    balances[msg.sender] = safeSub(balances[msg.sender], _value);
    balances[_to] = safeAdd(balances[_to], _value);
    Transfer(msg.sender, _to, _value);
    return true;
  }
  
  function transferToContract(address _to, uint _value) returns (bool success) {
    balances[msg.sender] = safeSub(balances[msg.sender], _value);
    balances[_to] = safeAdd(balances[_to], _value);
    contractReciever reciever = contractReciever(_to);
    reciever.fallbackToken(msg.sender, _value);
    Transfer(msg.sender, _to, _value);
    return true;
  }

  function transferFrom(address _from, address _to, uint _value) returns (bool success) {
    var _allowance = allowed[_from][msg.sender];

    // Check is not needed because safeSub(_allowance, _value) will already throw if this condition is not met
    // if (_value > _allowance) throw;

    balances[_to] = safeAdd(balances[_to], _value);
    balances[_from] = safeSub(balances[_from], _value);
    allowed[_from][msg.sender] = safeSub(_allowance, _value);
    Transfer(_from, _to, _value);
    return true;
  }

  function balanceOf(address _owner) constant returns (uint balance) {
    return balances[_owner];
  }

  function approve(address _spender, uint _value) returns (bool success) {
    allowed[msg.sender][_spender] = _value;
    Approval(msg.sender, _spender, _value);
    return true;
  }

  function allowance(address _owner, address _spender) constant returns (uint remaining) {
    return allowed[_owner][_spender];
  }

}