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authorDenton Liu <liu.denton+github@gmail.com>2016-05-06 03:31:00 +0800
committerDenton Liu <liu.denton+github@gmail.com>2016-05-06 03:31:00 +0800
commitffade949defb36730a3ea6019a2a3524db446a2e (patch)
treed0d31cdfb5098e362c2ec4442c55891a44e37bcf /docs/solidity-by-example.rst
parent88bb63a50700b461ea59f281dee6663dc2d72e23 (diff)
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Fixed up formatting
Diffstat (limited to 'docs/solidity-by-example.rst')
-rw-r--r--docs/solidity-by-example.rst156
1 files changed, 94 insertions, 62 deletions
diff --git a/docs/solidity-by-example.rst b/docs/solidity-by-example.rst
index 59400f3f..6a3de0cd 100644
--- a/docs/solidity-by-example.rst
+++ b/docs/solidity-by-example.rst
@@ -39,18 +39,17 @@ of votes.
::
/// @title Voting with delegation.
- contract Ballot
- {
+ contract Ballot {
// This declares a new complex type which will
// be used for variables later.
// It will represent a single voter.
- struct Voter
- {
+ struct Voter {
uint weight; // weight is accumulated by delegation
bool voted; // if true, that person already voted
address delegate; // person delegated to
uint vote; // index of the voted proposal
}
+
// This is a type for a single proposal.
struct Proposal
{
@@ -59,21 +58,23 @@ of votes.
}
address public chairperson;
+
// This declares a state variable that
// stores a `Voter` struct for each possible address.
mapping(address => Voter) public voters;
+
// A dynamically-sized array of `Proposal` structs.
Proposal[] public proposals;
/// Create a new ballot to choose one of `proposalNames`.
- function Ballot(bytes32[] proposalNames)
- {
+ function Ballot(bytes32[] proposalNames) {
chairperson = msg.sender;
voters[chairperson].weight = 1;
+
// For each of the provided proposal names,
// create a new proposal object and add it
// to the end of the array.
- for (uint i = 0; i < proposalNames.length; i++)
+ for (uint i = 0; i < proposalNames.length; i++) {
// `Proposal({...})` creates a temporary
// Proposal object and `proposal.push(...)`
// appends it to the end of `proposals`.
@@ -81,60 +82,68 @@ of votes.
name: proposalNames[i],
voteCount: 0
}));
+ }
}
// Give `voter` the right to vote on this ballot.
// May only be called by `chairperson`.
- function giveRightToVote(address voter)
- {
- if (msg.sender != chairperson || voters[voter].voted)
+ function giveRightToVote(address voter) {
+ if (msg.sender != chairperson || voters[voter].voted) {
// `throw` terminates and reverts all changes to
// the state and to Ether balances. It is often
// a good idea to use this if functions are
// called incorrectly. But watch out, this
// will also consume all provided gas.
throw;
+ }
voters[voter].weight = 1;
}
/// Delegate your vote to the voter `to`.
- function delegate(address to)
- {
+ function delegate(address to) {
// assigns reference
Voter sender = voters[msg.sender];
if (sender.voted)
throw;
+
// Forward the delegation as long as
// `to` also delegated.
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.
- if (to == msg.sender)
+ if (to == msg.sender) {
throw;
+ }
+
// Since `sender` is a reference, this
// modifies `voters[msg.sender].voted`
sender.voted = true;
sender.delegate = to;
Voter delegate = voters[to];
- if (delegate.voted)
+ if (delegate.voted) {
// If the delegate already voted,
// directly add to the number of votes
proposals[delegate.vote].voteCount += sender.weight;
- else
+ }
+ else {
// If the delegate did not vote yet,
// add to her weight.
delegate.weight += sender.weight;
+ }
}
/// Give your vote (including votes delegated to you)
/// to proposal `proposals[proposal].name`.
- function vote(uint proposal)
- {
+ function vote(uint proposal) {
Voter sender = voters[msg.sender];
- if (sender.voted) throw;
+ if (sender.voted)
+ throw;
sender.voted = true;
sender.vote = proposal;
+
// If `proposal` is out of the range of the array,
// this will throw automatically and revert all
// changes.
@@ -147,10 +156,8 @@ of votes.
returns (uint winningProposal)
{
uint winningVoteCount = 0;
- for (uint p = 0; p < proposals.length; p++)
- {
- if (proposals[p].voteCount > winningVoteCount)
- {
+ for (uint p = 0; p < proposals.length; p++) {
+ if (proposals[p].voteCount > winningVoteCount) {
winningVoteCount = proposals[p].voteCount;
winningProposal = p;
}
@@ -223,8 +230,10 @@ activate themselves.
/// Create a simple auction with `_biddingTime`
/// seconds bidding time on behalf of the
/// beneficiary address `_beneficiary`.
- function SimpleAuction(uint _biddingTime,
- address _beneficiary) {
+ function SimpleAuction(
+ uint _biddingTime,
+ address _beneficiary
+ ) {
beneficiary = _beneficiary;
auctionStart = now;
biddingTime = _biddingTime;
@@ -238,16 +247,19 @@ activate themselves.
// No arguments are necessary, all
// information is already part of
// the transaction.
- if (now > auctionStart + biddingTime)
+ if (now > auctionStart + biddingTime) {
// Revert the call if the bidding
// period is over.
throw;
- if (msg.value <= highestBid)
+ }
+ if (msg.value <= highestBid) {
// If the bid is not higher, send the
// money back.
throw;
- if (highestBidder != 0)
+ }
+ if (highestBidder != 0) {
highestBidder.send(highestBid);
+ }
highestBidder = msg.sender;
highestBid = msg.value;
HighestBidIncreased(msg.sender, msg.value);
@@ -261,6 +273,7 @@ activate themselves.
if (ended)
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);
@@ -319,13 +332,12 @@ high or low invalid bids.
::
- contract BlindAuction
- {
- struct Bid
- {
+ contract BlindAuction {
+ struct Bid {
bytes32 blindedBid;
uint deposit;
}
+
address public beneficiary;
uint public auctionStart;
uint public biddingEnd;
@@ -346,10 +358,11 @@ high or low invalid bids.
modifier onlyBefore(uint _time) { if (now >= _time) throw; _ }
modifier onlyAfter(uint _time) { if (now <= _time) throw; _ }
- function BlindAuction(uint _biddingTime,
- uint _revealTime,
- address _beneficiary)
- {
+ function BlindAuction(
+ uint _biddingTime,
+ uint _revealTime,
+ address _beneficiary
+ ) {
beneficiary = _beneficiary;
auctionStart = now;
biddingEnd = now + _biddingTime;
@@ -377,29 +390,38 @@ high or low invalid bids.
/// Reveal your blinded bids. You will get a refund for all
/// correctly blinded invalid bids and for all bids except for
/// the totally highest.
- function reveal(uint[] _values, bool[] _fake,
- bytes32[] _secret)
+ function reveal(
+ uint[] _values,
+ bool[] _fake,
+ bytes32[] _secret
+ )
onlyAfter(biddingEnd)
onlyBefore(revealEnd)
{
uint length = bids[msg.sender].length;
- if (_values.length != length || _fake.length != length ||
- _secret.length != length)
+ if (
+ _values.length != length
+ || _fake.length != length
+ || _secret.length != length
+ ) {
throw;
+ }
+
uint refund;
- for (uint i = 0; i < length; i++)
- {
+ for (uint i = 0; i < length; i++) {
var bid = bids[msg.sender][i];
var (value, fake, secret) =
(_values[i], _fake[i], _secret[i]);
- if (bid.blindedBid != sha3(value, fake, secret))
+ if (bid.blindedBid != sha3(value, fake, secret)) {
// Bid was not actually revealed.
// Do not refund deposit.
continue;
+ }
refund += bid.deposit;
- if (!fake && bid.deposit >= value)
+ if (!fake && bid.deposit >= value) {
if (placeBid(msg.sender, value))
refund -= value;
+ }
// Make it impossible for the sender to re-claim
// the same deposit.
bid.blindedBid = 0;
@@ -413,11 +435,13 @@ high or low invalid bids.
function placeBid(address bidder, uint value) internal
returns (bool success)
{
- if (value <= highestBid)
+ if (value <= highestBid) {
return false;
- if (highestBidder != 0)
+ }
+ if (highestBidder != 0) {
// Refund the previously highest bidder.
highestBidder.send(highestBid);
+ }
highestBid = value;
highestBidder = bidder;
return true;
@@ -428,7 +452,8 @@ high or low invalid bids.
function auctionEnd()
onlyAfter(revealEnd)
{
- if (ended) throw;
+ if (ended)
+ throw;
AuctionEnded(highestBidder, highestBid);
// We send all the money we have, because some
// of the refunds might have failed.
@@ -436,7 +461,9 @@ high or low invalid bids.
ended = true;
}
- function () { throw; }
+ function () {
+ throw;
+ }
}
.. index:: purchase, remote purchase, escrow
@@ -449,39 +476,39 @@ Safe Remote Purchase
::
- contract Purchase
- {
+ contract Purchase {
uint public value;
address public seller;
address public buyer;
enum State { Created, Locked, Inactive }
State public state;
- function Purchase()
- {
+
+ function Purchase() {
seller = msg.sender;
value = msg.value / 2;
if (2 * value != msg.value) throw;
}
- modifier require(bool _condition)
- {
+
+ modifier require(bool _condition) {
if (!_condition) throw;
_
}
- modifier onlyBuyer()
- {
+
+ modifier onlyBuyer() {
if (msg.sender != buyer) throw;
_
}
- modifier onlySeller()
- {
+
+ modifier onlySeller() {
if (msg.sender != seller) throw;
_
}
- modifier inState(State _state)
- {
+
+ modifier inState(State _state) {
if (state != _state) throw;
_
}
+
event aborted();
event purchaseConfirmed();
event itemReceived();
@@ -497,6 +524,7 @@ Safe Remote Purchase
seller.send(this.balance);
state = State.Inactive;
}
+
/// Confirm the purchase as buyer.
/// Transaction has to include `2 * value` ether.
/// The ether will be locked until confirmReceived
@@ -509,6 +537,7 @@ Safe Remote Purchase
buyer = msg.sender;
state = State.Locked;
}
+
/// Confirm that you (the buyer) received the item.
/// This will release the locked ether.
function confirmReceived()
@@ -520,7 +549,10 @@ Safe Remote Purchase
seller.send(this.balance);
state = State.Inactive;
}
- function() { throw; }
+
+ function() {
+ throw;
+ }
}
********************