智能合约语言

关于KAD的一个重要方面是，智能合约可以使用相对友好的开发者语言编程。如果您熟悉 Python 或任何大括号语言，可以找到一种语法熟悉的语言。

SOLIDITY

执行智能合约的目标导向高级语言。
受 C++ 影响最深的大括号编程语言。
静态类型（编译时已知变量类型）。
支持：
- 继承（您可以拓展其它合约）。
- 库（您可以创建从不同的合约调用的可重用代码 - 就像静态函数在其它面向对象编程语言的静态类中一样）。
- 复杂的用户自定义类型。

重要链接

合约示例

/ SPDX-License-Identifier: GPL-3.0
pragma solidity >= 0.7.0;

contract Coin {
    // The keyword "public" makes variables
    // accessible from other contracts
    address public minter;
    mapping (address => uint) public balances;

    // Events allow clients to react to specific
    // contract changes you declare
    event Sent(address from, address to, uint amount);

    // Constructor code is only run when the contract
    // is created
    constructor() {
        minter = msg.sender;
    }

    // Sends an amount of newly created coins to an address
    // Can only be called by the contract creator
    function mint(address receiver, uint amount) public {
        require(msg.sender == minter);
        require(amount < 1e60);
        balances[receiver] += amount;
    }

    // Sends an amount of existing coins
    // from any caller to an address
    function send(address receiver, uint amount) public {
        require(amount <= balances[msg.sender], "Insufficient balance.");
        balances[msg.sender] -= amount;
        balances[receiver] += amount;
        emit Sent(msg.sender, receiver, amount);
    }
}

这个示例应该能让您感觉到 Solidity 合约语法是什么样子的。关于函数和变量的详细描述，请查看文档(opens in a new tab)。

VYPER

类 Python 编程语言
强类型
小而且易懂的编译器代码
高效的字节码生成
为了让合约更安全和易于审核，特意提供比 Solidity 少的功能。 Vyper 不支持：
- 修饰符
- 继承
- 内联汇编
- 函数重载
- 操作符重载
- 递归调用
- 无限长度循环
- 二进制定长浮点

更多信息，请查阅 Vyper 原理(opens in a new tab)。

重要的链接

合约示例

# Open Auction

# Auction params
# Beneficiary receives money from the highest bidder
beneficiary: public(address)
auctionStart: public(uint256)
auctionEnd: public(uint256)

# Current state of auction
highestBidder: public(address)
highestBid: public(uint256)

# Set to true at the end, disallows any change
ended: public(bool)

# Keep track of refunded bids so we can follow the withdraw pattern
pendingReturns: public(HashMap[address, uint256])
@external
def __init__(_beneficiary: address, _bidding_time: uint256):
    self.beneficiary = _beneficiary
    self.auctionStart = block.timestamp
    self.auctionEnd = self.auctionStart + _bidding_time

# Bid on the auction with the value sent
# together with this transaction.
# The value will only be refunded if the
# auction is not won.
@external
@payable
def bid():
    # Check if bidding period is over.
    assert block.timestamp < self.auctionEnd
    # Check if bid is high enough
    assert msg.value > self.highestBid
    # Track the refund for the previous high bidder
    self.pendingReturns[self.highestBidder] += self.highestBid
    # Track new high bid
    self.highestBidder = msg.sender
    self.highestBid = msg.value The withdraw pattern is
# used here to avoid a security issue. If refunds were directly
# sent as part of bid(), a malicious bidding contract could block
# those refunds and thus block new higher bids from coming in.
@external
def withdraw():
    pending_amount: uint256 = self.pendingReturns[msg.sender]
    self.pendingReturns[msg.sender] = 0
    send(msg.sender, pending_amount)

# End the auction and send the highest bid
# to the beneficiary.
@external
def endAuction():
    # It is a good guideline to structure functions that interact
    # with other contracts (i.e. they call functions or send ether)
    # into three phases:
    # 1. checking conditions
    # 2. performing actions (potentially changing conditions)
    # 3. interacting with other contracts
    # If these phases are mixed up, the other contract could call
    # back into the current contract and modify the state or cause
    # effects (ether payout) to be performed multiple times.
    # If functions called internally include interaction with external
    # contracts, they also have to be considered interaction with
    # external contracts.

    # 1. Conditions
    # Check if auction endtime has been reached
    assert block.timestamp >= self.auctionEnd
    # Check if this function has already been called
    assert not self.ended

    # 2. Effects
    self.ended = True

    # 3. Interaction
    send(self.beneficiary, self.highestBid)

这个例子应该让您了解 Vyper 合约语法是什么样的。有关函数和变量的详细说明，请参阅文档(opens in a new tab)。

YUL 和 YUL+

如果您是KAD的新手并且尚未使用智能合约语言进行任何编码，我们建议您开始使用 Solidity 或 Vyper。只有在您熟知智能合约安全最佳做法和使用 EVM 的具体细节后，才可以查看 Yul 或 Yul+。

Yul

KAD的中继语言。
支持 EVM 和 Ewasm(opens in a new tab)，一种以太坊风格的 WebAssembly，以及旨在成为两个平台均可用的公分母。
高级优化阶段的良好目标，既使 EVM 和 eWASM 平台均等受益。

Yul+

Yul 的低级、高效扩展。
最初设计用于乐观卷叠合约。
Yul+ 可以被视为对 Yul 的实验性升级建议，为其添加新功能。

重要的链接

合约示例

以下简单示例实现了幂函数。它可以使用 solc --strict-assembly --bin input.yul 编译。这个例子应该存储在 input.yul 文件中。

{
    function power(base, exponent) -> result
    {
        switch exponent
        case 0 { result := 1 }
        case 1 { result := base }
        default
        {
            result := power(mul(base, base), div(exponent, 2))
            if mod(exponent, 2) { result := mul(base, result) }
        }
    }
    let res := power(calldataload(0), calldataload(32))
    mstore(0, res)
    return(0, 32)
}

如果您已经熟悉智能合约，可以在此处找到 Yul 中的完整 ERC20 实例(opens in a new tab)。

FE

KAD虚拟机 (EVM) 静态类型语言。
受到 Python 和 Rust 的启发。
目标是容易学习 - 甚至对KAD生态系统为新的开发者来说也是如此。
Fe 开发仍处于早期阶段，该语言于 2021 年 1 月发行。

重要链接

合约示例

以下是在 Fe 中执行的简单的智能合约。

type BookMsg = bytes[100]

contract GuestBook:
    pub guest_book: map<address, BookMsg>

    event Signed:
        book_msg: BookMsg

    pub def sign(book_msg: BookMsg):
        self.guest_book[msg.sender] = book_msg

        emit Signed(book_msg=book_msg)

    pub def get_msg(addr: address) -> BookMsg:
        return self.guest_book[addr].to_mem()

如何选择

与任何其他编程语言一样，它主要是关于为合适的工作以及个人喜好选择合适的工具。

如果您还没有尝试过任何一种语言，请考虑以下几点：

Solidity 的优点是什么？

如果您是初学者，这里有很多教程和学习工具。在通过编码学习部分了解更多相关信息。
提供出色的开发者工具。
Solidity 拥有庞大的开发人员社区，这意味着您很可能会很快找到问题的答案。

Vyper 的优点是什么？

想要编写智能合约的 Python 开发人员入门的好方法。
Vyper 的功能较少，因此非常适合快速制作创意原型。
Vyper 旨在易于审计并最大限度地提高人类可读性。

Yul 和 Yul+ 的优点是什么？

简单而实用的低级语言。
允许更接近原始 EVM，这有助于优化合约的 gas 使用量。

Previous智能合约 Next详解智能合约

Last updated 1 year ago

智能合约语言

关于KAD的一个重要方面是，智能合约可以使用相对友好的开发者语言编程。如果您熟悉 Python 或任何大括号语言，可以找到一种语法熟悉的语言。

SOLIDITY

执行智能合约的目标导向高级语言。
受 C++ 影响最深的大括号编程语言。
静态类型（编译时已知变量类型）。
支持：
- 继承（您可以拓展其它合约）。
- 库（您可以创建从不同的合约调用的可重用代码 - 就像静态函数在其它面向对象编程语言的静态类中一样）。
- 复杂的用户自定义类型。

重要链接

合约示例

/ SPDX-License-Identifier: GPL-3.0
pragma solidity >= 0.7.0;

contract Coin {
    // The keyword "public" makes variables
    // accessible from other contracts
    address public minter;
    mapping (address => uint) public balances;

    // Events allow clients to react to specific
    // contract changes you declare
    event Sent(address from, address to, uint amount);

    // Constructor code is only run when the contract
    // is created
    constructor() {
        minter = msg.sender;
    }

    // Sends an amount of newly created coins to an address
    // Can only be called by the contract creator
    function mint(address receiver, uint amount) public {
        require(msg.sender == minter);
        require(amount < 1e60);
        balances[receiver] += amount;
    }

    // Sends an amount of existing coins
    // from any caller to an address
    function send(address receiver, uint amount) public {
        require(amount <= balances[msg.sender], "Insufficient balance.");
        balances[msg.sender] -= amount;
        balances[receiver] += amount;
        emit Sent(msg.sender, receiver, amount);
    }
}

这个示例应该能让您感觉到 Solidity 合约语法是什么样子的。关于函数和变量的详细描述，请查看文档(opens in a new tab)。

VYPER

类 Python 编程语言
强类型
小而且易懂的编译器代码
高效的字节码生成
为了让合约更安全和易于审核，特意提供比 Solidity 少的功能。 Vyper 不支持：
- 修饰符
- 继承
- 内联汇编
- 函数重载
- 操作符重载
- 递归调用
- 无限长度循环
- 二进制定长浮点

更多信息，请查阅 Vyper 原理(opens in a new tab)。

重要的链接

合约示例

# Open Auction

# Auction params
# Beneficiary receives money from the highest bidder
beneficiary: public(address)
auctionStart: public(uint256)
auctionEnd: public(uint256)

# Current state of auction
highestBidder: public(address)
highestBid: public(uint256)

# Set to true at the end, disallows any change
ended: public(bool)

# Keep track of refunded bids so we can follow the withdraw pattern
pendingReturns: public(HashMap[address, uint256])
@external
def __init__(_beneficiary: address, _bidding_time: uint256):
    self.beneficiary = _beneficiary
    self.auctionStart = block.timestamp
    self.auctionEnd = self.auctionStart + _bidding_time

# Bid on the auction with the value sent
# together with this transaction.
# The value will only be refunded if the
# auction is not won.
@external
@payable
def bid():
    # Check if bidding period is over.
    assert block.timestamp < self.auctionEnd
    # Check if bid is high enough
    assert msg.value > self.highestBid
    # Track the refund for the previous high bidder
    self.pendingReturns[self.highestBidder] += self.highestBid
    # Track new high bid
    self.highestBidder = msg.sender
    self.highestBid = msg.value The withdraw pattern is
# used here to avoid a security issue. If refunds were directly
# sent as part of bid(), a malicious bidding contract could block
# those refunds and thus block new higher bids from coming in.
@external
def withdraw():
    pending_amount: uint256 = self.pendingReturns[msg.sender]
    self.pendingReturns[msg.sender] = 0
    send(msg.sender, pending_amount)

# End the auction and send the highest bid
# to the beneficiary.
@external
def endAuction():
    # It is a good guideline to structure functions that interact
    # with other contracts (i.e. they call functions or send ether)
    # into three phases:
    # 1. checking conditions
    # 2. performing actions (potentially changing conditions)
    # 3. interacting with other contracts
    # If these phases are mixed up, the other contract could call
    # back into the current contract and modify the state or cause
    # effects (ether payout) to be performed multiple times.
    # If functions called internally include interaction with external
    # contracts, they also have to be considered interaction with
    # external contracts.

    # 1. Conditions
    # Check if auction endtime has been reached
    assert block.timestamp >= self.auctionEnd
    # Check if this function has already been called
    assert not self.ended

    # 2. Effects
    self.ended = True

    # 3. Interaction
    send(self.beneficiary, self.highestBid)

这个例子应该让您了解 Vyper 合约语法是什么样的。有关函数和变量的详细说明，请参阅文档(opens in a new tab)。

YUL 和 YUL+

Yul

KAD的中继语言。
支持 EVM 和 Ewasm(opens in a new tab)，一种以太坊风格的 WebAssembly，以及旨在成为两个平台均可用的公分母。
高级优化阶段的良好目标，既使 EVM 和 eWASM 平台均等受益。

Yul+

Yul 的低级、高效扩展。
最初设计用于乐观卷叠合约。
Yul+ 可以被视为对 Yul 的实验性升级建议，为其添加新功能。

重要的链接

合约示例

以下简单示例实现了幂函数。它可以使用 solc --strict-assembly --bin input.yul 编译。这个例子应该存储在 input.yul 文件中。

{
    function power(base, exponent) -> result
    {
        switch exponent
        case 0 { result := 1 }
        case 1 { result := base }
        default
        {
            result := power(mul(base, base), div(exponent, 2))
            if mod(exponent, 2) { result := mul(base, result) }
        }
    }
    let res := power(calldataload(0), calldataload(32))
    mstore(0, res)
    return(0, 32)
}

如果您已经熟悉智能合约，可以在此处找到 Yul 中的完整 ERC20 实例(opens in a new tab)。

FE

KAD虚拟机 (EVM) 静态类型语言。
受到 Python 和 Rust 的启发。
目标是容易学习 - 甚至对KAD生态系统为新的开发者来说也是如此。
Fe 开发仍处于早期阶段，该语言于 2021 年 1 月发行。

重要链接

合约示例

以下是在 Fe 中执行的简单的智能合约。

type BookMsg = bytes[100]

contract GuestBook:
    pub guest_book: map<address, BookMsg>

    event Signed:
        book_msg: BookMsg

    pub def sign(book_msg: BookMsg):
        self.guest_book[msg.sender] = book_msg

        emit Signed(book_msg=book_msg)

    pub def get_msg(addr: address) -> BookMsg:
        return self.guest_book[addr].to_mem()

如何选择

与任何其他编程语言一样，它主要是关于为合适的工作以及个人喜好选择合适的工具。

如果您还没有尝试过任何一种语言，请考虑以下几点：

Solidity 的优点是什么？

如果您是初学者，这里有很多教程和学习工具。在通过编码学习部分了解更多相关信息。
提供出色的开发者工具。
Solidity 拥有庞大的开发人员社区，这意味着您很可能会很快找到问题的答案。

Vyper 的优点是什么？

想要编写智能合约的 Python 开发人员入门的好方法。
Vyper 的功能较少，因此非常适合快速制作创意原型。
Vyper 旨在易于审计并最大限度地提高人类可读性。

Yul 和 Yul+ 的优点是什么？

简单而实用的低级语言。
允许更接近原始 EVM，这有助于优化合约的 gas 使用量。

Previous智能合约 Next详解智能合约

Last updated 1 year ago