mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
Removed some problems in documentation examples.
This commit is contained in:
chriseth
parent
4be92c0c39
commit
f9c8a9b5ca
@ -28,8 +28,6 @@ functions and this is what this page is about.
|
||||
The use of **function modifiers** makes these
|
||||
restrictions highly readable.
|
||||
|
||||
.. {% include open_link gist="fe4ef267cbdeac151b98" %}
|
||||
|
||||
::
|
||||
|
||||
contract AccessRestriction {
|
||||
@ -167,8 +165,6 @@ function finishes.
|
||||
return. If you want to do that, make sure
|
||||
to call nextStage manually from those functions.
|
||||
|
||||
.. {% include open_link gist="0a221eaceb6d708bf271" %}
|
||||
|
||||
::
|
||||
|
||||
contract StateMachine {
|
||||
|
||||
@ -14,8 +14,6 @@ right now, we will go into more detail later.
|
||||
Storage
|
||||
=======
|
||||
|
||||
.. Gist: a4532ce30246847b371b
|
||||
|
||||
::
|
||||
|
||||
contract SimpleStorage {
|
||||
@ -63,8 +61,6 @@ Furthermore, anyone can send coins to each other without any need for
|
||||
registering with username and password - all you need is an Ethereum keypair.
|
||||
|
||||
|
||||
.. Gist: ad490694f3e5b3de47ab
|
||||
|
||||
::
|
||||
|
||||
contract Coin {
|
||||
|
||||
@ -34,8 +34,6 @@ At the end of the voting time, ``winningProposal()``
|
||||
will return the proposal with the largest number
|
||||
of votes.
|
||||
|
||||
.. Gist: 618560d3f740204d46a5
|
||||
|
||||
::
|
||||
|
||||
/// @title Voting with delegation.
|
||||
@ -108,9 +106,15 @@ of votes.
|
||||
|
||||
// Forward the delegation as long as
|
||||
// `to` also delegated.
|
||||
// In general, such loops are very dangerous,
|
||||
// because if they run too long, they might
|
||||
// need more gas that is available in a block.
|
||||
// In this case, the delegation will not be executed,
|
||||
// but in other situations, such loops might
|
||||
// cause a contract to get "stuck" completely.
|
||||
while (voters[to].delegate != address(0) &&
|
||||
voters[to].delegate != msg.sender) {
|
||||
to = voters[to].delegate;
|
||||
voters[to].delegate != msg.sender) {
|
||||
to = voters[to].delegate;
|
||||
}
|
||||
|
||||
// We found a loop in the delegation, not allowed.
|
||||
@ -199,8 +203,6 @@ contract has to be called manually for the
|
||||
beneficiary to receive his money - contracts cannot
|
||||
activate themselves.
|
||||
|
||||
.. {% include open_link gist="48cd2b65ff83bd04f7af" %}
|
||||
|
||||
::
|
||||
|
||||
contract SimpleAuction {
|
||||
@ -215,6 +217,9 @@ activate themselves.
|
||||
address public highestBidder;
|
||||
uint public highestBid;
|
||||
|
||||
// Allowed withdrawals of previous bids
|
||||
mapping(address => uint) pendingReturns;
|
||||
|
||||
// Set to true at the end, disallows any change
|
||||
bool ended;
|
||||
|
||||
@ -258,13 +263,29 @@ activate themselves.
|
||||
throw;
|
||||
}
|
||||
if (highestBidder != 0) {
|
||||
highestBidder.send(highestBid);
|
||||
// Sending back the money by simply using
|
||||
// highestBidder.send(highestBid) is a security risk
|
||||
// because it can be prevented by the caller by e.g.
|
||||
// raising the call stack to 1023. It is always safer
|
||||
// to let the recipient withdraw their money themselves.
|
||||
pendingReturns[highestBidder] += highestBid;
|
||||
}
|
||||
highestBidder = msg.sender;
|
||||
highestBid = msg.value;
|
||||
HighestBidIncreased(msg.sender, msg.value);
|
||||
}
|
||||
|
||||
/// Withdraw a bid that was overbid.
|
||||
function withdraw() {
|
||||
var amount = pendingReturns[msg.sender];
|
||||
// It is important to set this to zero because the recipient
|
||||
// can call this function again as part of the receiving call
|
||||
// before `send` returns.
|
||||
pendingReturns[msg.sender] = 0;
|
||||
if (!msg.sender.send(amount))
|
||||
throw; // If anything fails, this will revert the changes above
|
||||
}
|
||||
|
||||
/// End the auction and send the highest bid
|
||||
/// to the beneficiary.
|
||||
function auctionEnd() {
|
||||
@ -274,9 +295,8 @@ activate themselves.
|
||||
throw; // this function has already been called
|
||||
AuctionEnded(highestBidder, highestBid);
|
||||
|
||||
// We send all the money we have, because some
|
||||
// of the refunds might have failed.
|
||||
beneficiary.send(this.balance);
|
||||
if (!beneficiary.send(highestBid))
|
||||
throw;
|
||||
ended = true;
|
||||
}
|
||||
|
||||
@ -328,8 +348,6 @@ Bidders can confuse competition by placing several
|
||||
high or low invalid bids.
|
||||
|
||||
|
||||
.. {% include open_link gist="70528429c2cd867dd1d6" %}
|
||||
|
||||
::
|
||||
|
||||
contract BlindAuction {
|
||||
@ -349,6 +367,9 @@ high or low invalid bids.
|
||||
address public highestBidder;
|
||||
uint public highestBid;
|
||||
|
||||
// Allowed withdrawals of previous bids
|
||||
mapping(address => uint) pendingReturns;
|
||||
|
||||
event AuctionEnded(address winner, uint highestBid);
|
||||
|
||||
/// Modifiers are a convenient way to validate inputs to
|
||||
@ -426,7 +447,8 @@ high or low invalid bids.
|
||||
// the same deposit.
|
||||
bid.blindedBid = 0;
|
||||
}
|
||||
msg.sender.send(refund);
|
||||
if (!msg.sender.send(refund))
|
||||
throw;
|
||||
}
|
||||
|
||||
// This is an "internal" function which means that it
|
||||
@ -440,13 +462,24 @@ high or low invalid bids.
|
||||
}
|
||||
if (highestBidder != 0) {
|
||||
// Refund the previously highest bidder.
|
||||
highestBidder.send(highestBid);
|
||||
pendingReturns[highestBidder] += highestBid;
|
||||
}
|
||||
highestBid = value;
|
||||
highestBidder = bidder;
|
||||
return true;
|
||||
}
|
||||
|
||||
/// Withdraw a bid that was overbid.
|
||||
function withdraw() {
|
||||
var amount = pendingReturns[msg.sender];
|
||||
// It is important to set this to zero because the recipient
|
||||
// can call this function again as part of the receiving call
|
||||
// before `send` returns.
|
||||
pendingReturns[msg.sender] = 0;
|
||||
if (!msg.sender.send(amount))
|
||||
throw; // If anything fails, this will revert the changes above
|
||||
}
|
||||
|
||||
/// End the auction and send the highest bid
|
||||
/// to the beneficiary.
|
||||
function auctionEnd()
|
||||
@ -457,7 +490,8 @@ high or low invalid bids.
|
||||
AuctionEnded(highestBidder, highestBid);
|
||||
// We send all the money we have, because some
|
||||
// of the refunds might have failed.
|
||||
beneficiary.send(this.balance);
|
||||
if (!beneficiary.send(this.balance))
|
||||
throw;
|
||||
ended = true;
|
||||
}
|
||||
|
||||
@ -472,8 +506,6 @@ high or low invalid bids.
|
||||
Safe Remote Purchase
|
||||
********************
|
||||
|
||||
.. {% include open_link gist="b16e8e76a423b7671e99" %}
|
||||
|
||||
::
|
||||
|
||||
contract Purchase {
|
||||
@ -521,8 +553,9 @@ Safe Remote Purchase
|
||||
inState(State.Created)
|
||||
{
|
||||
aborted();
|
||||
seller.send(this.balance);
|
||||
state = State.Inactive;
|
||||
if (!seller.send(this.balance))
|
||||
throw;
|
||||
}
|
||||
|
||||
/// Confirm the purchase as buyer.
|
||||
@ -545,9 +578,14 @@ Safe Remote Purchase
|
||||
inState(State.Locked)
|
||||
{
|
||||
itemReceived();
|
||||
buyer.send(value); // We ignore the return value on purpose
|
||||
seller.send(this.balance);
|
||||
// It is important to change the state first because
|
||||
// otherwise, the contracts called using `send` below
|
||||
// can call in again here.
|
||||
state = State.Inactive;
|
||||
// This actually allows both the buyer and the seller to
|
||||
// block the refund.
|
||||
if (!buyer.send(value) || !seller.send(this.balance))
|
||||
throw;
|
||||
}
|
||||
|
||||
function() {
|
||||
|
||||
Loading…
Reference in New Issue
Block a user