std/ExampleToken


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55

import "./Token";

contract ExampleToken is Token {
    uint256 tokenSupply;
    mapping (address => uint256) balances;
    mapping (address =>
        mapping (address => uint256)) approvedTransfers;

    function ExampleToken(address _initialOwner, uint256 _supply) {
        tokenSupply = _supply;
        balances[_initialOwner] = _supply;
    }

    function totalSupply() constant returns (uint256 supply) {
        return tokenSupply;
    }

    function balanceOf(address _owner) constant returns (uint256 balance) {
        return balances[_owner];
    }

    function transfer(address _to, uint256 _value) returns (bool success) {
        if (balances[msg.sender] >= _value) {
            balances[msg.sender] -= _value;
            balances[_to] += _value;
            Transfer(msg.sender, _to, _value);
            return true;
        }
        else {
            return false;
        }
    }

    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
        if (approvedTransfers[_from][msg.sender] >= _value) {
            approvedTransfers[_from][msg.sender] -= _value;
            balances[_to] += _value;
            Transfer(_from, _to, _value);
            return true;
        }
        else {
            return false;
        }
    }

    function approve(address _spender, uint256 _value) returns (bool success) {
        approvedTransfers[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }

    function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
        return approvedTransfers[_owner][_spender];
    }
}