Contract Name:
Achievements
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./utils/Bytecode.sol";
/**
@title A key-value storage with auto-generated keys for storing chunks of data with a lower write & read cost.
@author Agustin Aguilar <[email protected]>
Readme: https://github.com/0xsequence/sstore2#readme
*/
library SSTORE2 {
error WriteError();
/**
@notice Stores `_data` and returns `pointer` as key for later retrieval
@dev The pointer is a contract address with `_data` as code
@param _data to be written
@return pointer Pointer to the written `_data`
*/
function write(bytes memory _data) internal returns (address pointer) {
// Append 00 to _data so contract can't be called
// Build init code
bytes memory code = Bytecode.creationCodeFor(
abi.encodePacked(
hex'00',
_data
)
);
// Deploy contract using create
assembly { pointer := create(0, add(code, 32), mload(code)) }
// Address MUST be non-zero
if (pointer == address(0)) revert WriteError();
}
/**
@notice Reads the contents of the `_pointer` code as data, skips the first byte
@dev The function is intended for reading pointers generated by `write`
@param _pointer to be read
@return data read from `_pointer` contract
*/
function read(address _pointer) internal view returns (bytes memory) {
return Bytecode.codeAt(_pointer, 1, type(uint256).max);
}
/**
@notice Reads the contents of the `_pointer` code as data, skips the first byte
@dev The function is intended for reading pointers generated by `write`
@param _pointer to be read
@param _start number of bytes to skip
@return data read from `_pointer` contract
*/
function read(address _pointer, uint256 _start) internal view returns (bytes memory) {
return Bytecode.codeAt(_pointer, _start + 1, type(uint256).max);
}
/**
@notice Reads the contents of the `_pointer` code as data, skips the first byte
@dev The function is intended for reading pointers generated by `write`
@param _pointer to be read
@param _start number of bytes to skip
@param _end index before which to end extraction
@return data read from `_pointer` contract
*/
function read(address _pointer, uint256 _start, uint256 _end) internal view returns (bytes memory) {
return Bytecode.codeAt(_pointer, _start + 1, _end + 1);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
library Bytecode {
error InvalidCodeAtRange(uint256 _size, uint256 _start, uint256 _end);
/**
@notice Generate a creation code that results on a contract with `_code` as bytecode
@param _code The returning value of the resulting `creationCode`
@return creationCode (constructor) for new contract
*/
function creationCodeFor(bytes memory _code) internal pure returns (bytes memory) {
/*
0x00 0x63 0x63XXXXXX PUSH4 _code.length size
0x01 0x80 0x80 DUP1 size size
0x02 0x60 0x600e PUSH1 14 14 size size
0x03 0x60 0x6000 PUSH1 00 0 14 size size
0x04 0x39 0x39 CODECOPY size
0x05 0x60 0x6000 PUSH1 00 0 size
0x06 0xf3 0xf3 RETURN
<CODE>
*/
return abi.encodePacked(
hex"63",
uint32(_code.length),
hex"80_60_0E_60_00_39_60_00_F3",
_code
);
}
/**
@notice Returns the size of the code on a given address
@param _addr Address that may or may not contain code
@return size of the code on the given `_addr`
*/
function codeSize(address _addr) internal view returns (uint256 size) {
assembly { size := extcodesize(_addr) }
}
/**
@notice Returns the code of a given address
@dev It will fail if `_end < _start`
@param _addr Address that may or may not contain code
@param _start number of bytes of code to skip on read
@param _end index before which to end extraction
@return oCode read from `_addr` deployed bytecode
Forked from: https://gist.github.com/KardanovIR/fe98661df9338c842b4a30306d507fbd
*/
function codeAt(address _addr, uint256 _start, uint256 _end) internal view returns (bytes memory oCode) {
uint256 csize = codeSize(_addr);
if (csize == 0) return bytes("");
if (_start > csize) return bytes("");
if (_end < _start) revert InvalidCodeAtRange(csize, _start, _end);
unchecked {
uint256 reqSize = _end - _start;
uint256 maxSize = csize - _start;
uint256 size = maxSize < reqSize ? maxSize : reqSize;
assembly {
// allocate output byte array - this could also be done without assembly
// by using o_code = new bytes(size)
oCode := mload(0x40)
// new "memory end" including padding
mstore(0x40, add(oCode, and(add(add(size, 0x20), 0x1f), not(0x1f))))
// store length in memory
mstore(oCode, size)
// actually retrieve the code, this needs assembly
extcodecopy(_addr, add(oCode, 0x20), _start, size)
}
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)
pragma solidity ^0.8.0;
import "../IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Enumerable is IERC721 {
/**
* @dev Returns the total amount of tokens stored by the contract.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns a token ID owned by `owner` at a given `index` of its token list.
* Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
*/
function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);
/**
* @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
* Use along with {totalSupply} to enumerate all tokens.
*/
function tokenByIndex(uint256 index) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC721.sol";
/**
* @title ERC-721 Non-Fungible Token Standard, optional metadata extension
* @dev See https://eips.ethereum.org/EIPS/eip-721
*/
interface IERC721Metadata is IERC721 {
/**
* @dev Returns the token collection name.
*/
function name() external view returns (string memory);
/**
* @dev Returns the token collection symbol.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
*/
function tokenURI(uint256 tokenId) external view returns (string memory);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC721/IERC721.sol)
pragma solidity ^0.8.0;
import "../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface IERC721 is IERC165 {
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function ownerOf(uint256 tokenId) external view returns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(address from, address to, uint256 tokenId) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
* or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
* understand this adds an external call which potentially creates a reentrancy vulnerability.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 tokenId) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/
function setApprovalForAll(address operator, bool approved) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/
function getApproved(uint256 tokenId) external view returns (address operator);
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/
function isApprovedForAll(address owner, address operator) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)
pragma solidity ^0.8.0;
/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/
interface IERC721Receiver {
/**
* @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
* by `operator` from `from`, this function is called.
*
* It must return its Solidity selector to confirm the token transfer.
* If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
*
* The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
*/
function onERC721Received(
address operator,
address from,
uint256 tokenId,
bytes calldata data
) external returns (bytes4);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/cryptography/ECDSA.sol)
pragma solidity ^0.8.0;
import "../Strings.sol";
/**
* @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
*
* These functions can be used to verify that a message was signed by the holder
* of the private keys of a given address.
*/
library ECDSA {
enum RecoverError {
NoError,
InvalidSignature,
InvalidSignatureLength,
InvalidSignatureS,
InvalidSignatureV // Deprecated in v4.8
}
function _throwError(RecoverError error) private pure {
if (error == RecoverError.NoError) {
return; // no error: do nothing
} else if (error == RecoverError.InvalidSignature) {
revert("ECDSA: invalid signature");
} else if (error == RecoverError.InvalidSignatureLength) {
revert("ECDSA: invalid signature length");
} else if (error == RecoverError.InvalidSignatureS) {
revert("ECDSA: invalid signature 's' value");
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature` or error string. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*
* Documentation for signature generation:
* - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
* - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
*
* _Available since v4.3._
*/
function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
if (signature.length == 65) {
bytes32 r;
bytes32 s;
uint8 v;
// ecrecover takes the signature parameters, and the only way to get them
// currently is to use assembly.
/// @solidity memory-safe-assembly
assembly {
r := mload(add(signature, 0x20))
s := mload(add(signature, 0x40))
v := byte(0, mload(add(signature, 0x60)))
}
return tryRecover(hash, v, r, s);
} else {
return (address(0), RecoverError.InvalidSignatureLength);
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature`. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*/
function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, signature);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
*
* See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
*
* _Available since v4.3._
*/
function tryRecover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address, RecoverError) {
bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
uint8 v = uint8((uint256(vs) >> 255) + 27);
return tryRecover(hash, v, r, s);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
*
* _Available since v4.2._
*/
function recover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, r, vs);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `v`,
* `r` and `s` signature fields separately.
*
* _Available since v4.3._
*/
function tryRecover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address, RecoverError) {
// EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
// unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
// the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
// signatures from current libraries generate a unique signature with an s-value in the lower half order.
//
// If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
// with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
// vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
// these malleable signatures as well.
if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
return (address(0), RecoverError.InvalidSignatureS);
}
// If the signature is valid (and not malleable), return the signer address
address signer = ecrecover(hash, v, r, s);
if (signer == address(0)) {
return (address(0), RecoverError.InvalidSignature);
}
return (signer, RecoverError.NoError);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `v`,
* `r` and `s` signature fields separately.
*/
function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, v, r, s);
_throwError(error);
return recovered;
}
/**
* @dev Returns an Ethereum Signed Message, created from a `hash`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/
function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32 message) {
// 32 is the length in bytes of hash,
// enforced by the type signature above
/// @solidity memory-safe-assembly
assembly {
mstore(0x00, "\x19Ethereum Signed Message:\n32")
mstore(0x1c, hash)
message := keccak256(0x00, 0x3c)
}
}
/**
* @dev Returns an Ethereum Signed Message, created from `s`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/
function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
}
/**
* @dev Returns an Ethereum Signed Typed Data, created from a
* `domainSeparator` and a `structHash`. This produces hash corresponding
* to the one signed with the
* https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
* JSON-RPC method as part of EIP-712.
*
* See {recover}.
*/
function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32 data) {
/// @solidity memory-safe-assembly
assembly {
let ptr := mload(0x40)
mstore(ptr, "\x19\x01")
mstore(add(ptr, 0x02), domainSeparator)
mstore(add(ptr, 0x22), structHash)
data := keccak256(ptr, 0x42)
}
}
/**
* @dev Returns an Ethereum Signed Data with intended validator, created from a
* `validator` and `data` according to the version 0 of EIP-191.
*
* See {recover}.
*/
function toDataWithIntendedValidatorHash(address validator, bytes memory data) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19\x00", validator, data));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
enum Rounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds up instead
* of rounding down.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b - 1) / b can overflow on addition, so we distribute.
return a == 0 ? 0 : (a - 1) / b + 1;
}
/**
* @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
* @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
* with further edits by Uniswap Labs also under MIT license.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
unchecked {
// 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
// use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = prod1 * 2^256 + prod0.
uint256 prod0; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
prod0 := mul(x, y)
prod1 := sub(sub(mm, prod0), lt(mm, prod0))
}
// Handle non-overflow cases, 256 by 256 division.
if (prod1 == 0) {
// Solidity will revert if denominator == 0, unlike the div opcode on its own.
// The surrounding unchecked block does not change this fact.
// See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
return prod0 / denominator;
}
// Make sure the result is less than 2^256. Also prevents denominator == 0.
require(denominator > prod1, "Math: mulDiv overflow");
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [prod1 prod0].
uint256 remainder;
assembly {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
prod1 := sub(prod1, gt(remainder, prod0))
prod0 := sub(prod0, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
// See https://cs.stackexchange.com/q/138556/92363.
// Does not overflow because the denominator cannot be zero at this stage in the function.
uint256 twos = denominator & (~denominator + 1);
assembly {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [prod1 prod0] by twos.
prod0 := div(prod0, twos)
// Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from prod1 into prod0.
prod0 |= prod1 * twos;
// Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
// that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv = 1 mod 2^4.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
// in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2^8
inverse *= 2 - denominator * inverse; // inverse mod 2^16
inverse *= 2 - denominator * inverse; // inverse mod 2^32
inverse *= 2 - denominator * inverse; // inverse mod 2^64
inverse *= 2 - denominator * inverse; // inverse mod 2^128
inverse *= 2 - denominator * inverse; // inverse mod 2^256
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
// less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
// is no longer required.
result = prod0 * inverse;
return result;
}
}
/**
* @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
uint256 result = mulDiv(x, y, denominator);
if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
result += 1;
}
return result;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
*
* Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
*/
function sqrt(uint256 a) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
// For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
//
// We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
// `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
//
// This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
// → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
// → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
//
// Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
uint256 result = 1 << (log2(a) >> 1);
// At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
// since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
// every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
// into the expected uint128 result.
unchecked {
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
return min(result, a / result);
}
}
/**
* @notice Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 128;
}
if (value >> 64 > 0) {
value >>= 64;
result += 64;
}
if (value >> 32 > 0) {
value >>= 32;
result += 32;
}
if (value >> 16 > 0) {
value >>= 16;
result += 16;
}
if (value >> 8 > 0) {
value >>= 8;
result += 8;
}
if (value >> 4 > 0) {
value >>= 4;
result += 4;
}
if (value >> 2 > 0) {
value >>= 2;
result += 2;
}
if (value >> 1 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10 ** 64) {
value /= 10 ** 64;
result += 64;
}
if (value >= 10 ** 32) {
value /= 10 ** 32;
result += 32;
}
if (value >= 10 ** 16) {
value /= 10 ** 16;
result += 16;
}
if (value >= 10 ** 8) {
value /= 10 ** 8;
result += 8;
}
if (value >= 10 ** 4) {
value /= 10 ** 4;
result += 4;
}
if (value >= 10 ** 2) {
value /= 10 ** 2;
result += 2;
}
if (value >= 10 ** 1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256, rounded down, of a positive value.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 16;
}
if (value >> 64 > 0) {
value >>= 64;
result += 8;
}
if (value >> 32 > 0) {
value >>= 32;
result += 4;
}
if (value >> 16 > 0) {
value >>= 16;
result += 2;
}
if (value >> 8 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 256, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard signed math utilities missing in the Solidity language.
*/
library SignedMath {
/**
* @dev Returns the largest of two signed numbers.
*/
function max(int256 a, int256 b) internal pure returns (int256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two signed numbers.
*/
function min(int256 a, int256 b) internal pure returns (int256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two signed numbers without overflow.
* The result is rounded towards zero.
*/
function average(int256 a, int256 b) internal pure returns (int256) {
// Formula from the book "Hacker's Delight"
int256 x = (a & b) + ((a ^ b) >> 1);
return x + (int256(uint256(x) >> 255) & (a ^ b));
}
/**
* @dev Returns the absolute unsigned value of a signed value.
*/
function abs(int256 n) internal pure returns (uint256) {
unchecked {
// must be unchecked in order to support `n = type(int256).min`
return uint256(n >= 0 ? n : -n);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)
pragma solidity ^0.8.0;
import "./math/Math.sol";
import "./math/SignedMath.sol";
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _SYMBOLS = "0123456789abcdef";
uint8 private constant _ADDRESS_LENGTH = 20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
unchecked {
uint256 length = Math.log10(value) + 1;
string memory buffer = new string(length);
uint256 ptr;
/// @solidity memory-safe-assembly
assembly {
ptr := add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assembly
assembly {
mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
}
value /= 10;
if (value == 0) break;
}
return buffer;
}
}
/**
* @dev Converts a `int256` to its ASCII `string` decimal representation.
*/
function toString(int256 value) internal pure returns (string memory) {
return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
unchecked {
return toHexString(value, Math.log256(value) + 1);
}
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = _SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/
function toHexString(address addr) internal pure returns (string memory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
/**
* @dev Returns true if the two strings are equal.
*/
function equal(string memory a, string memory b) internal pure returns (bool) {
return keccak256(bytes(a)) == keccak256(bytes(b));
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import "@0xsequence/sstore2/contracts/SSTORE2.sol";
import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
import "solady/src/utils/LibString.sol";
import "solady/src/utils/Base64.sol";
import "./LeetCollectiveGuarded.sol";
import "./LeetERC721.sol";
/**
* @title Claim your achievements within 1337 ecosystem
* @author hoanh.eth
* @author snjolfur.eth
*/
contract Achievements is ERC721L, LeetCollectiveGuarded {
bool public isOpen;
bool public useExternalURI;
string public externalURI;
using ECDSA for bytes32;
address private _offchainSigner;
mapping(bytes32 => bool) private _claimed;
Achievement[] private _achievements;
uint256[] private _tokens;
error AlreadyClaimed();
error ClaimClosed();
error InvalidExternalURI();
error InvalidPayload();
error InvalidOffchainSigner();
error TraitsMustBePairs();
struct Achievement {
address image;
string name;
string description;
string[] traits;
}
constructor(string memory name, string memory symbol, address collective)
ERC721L(name, symbol, "Achievements within the 1337 ecosystem")
LeetCollectiveGuarded(collective)
{}
function toggleClaim() external serOrOwner {
isOpen = !isOpen;
}
function toggleExternalURI() external serOrOwner {
useExternalURI = !useExternalURI;
}
function setOffchainSigner(address addr) external serOrOwner {
_offchainSigner = addr;
}
function setExternalURI(string memory url) external serOrOwner {
externalURI = url;
}
function hasClaim(address addr, uint256 achievementID) public view returns (bool) {
bytes32 msgHash = keccak256(abi.encodePacked(addr, achievementID));
return _claimed[msgHash];
}
function add(bytes memory image, string memory name, string memory description, string[] calldata traits)
public
serOrOwner
{
if (traits.length % 2 != 0) revert TraitsMustBePairs();
Achievement memory achievement;
achievement.image = SSTORE2.write(image);
achievement.name = name;
achievement.description = description;
achievement.traits = traits;
_achievements.push(achievement);
}
function change(
uint256 achievementID,
bytes calldata image,
string calldata name,
string calldata description,
string[] calldata traits
) external serOrOwner {
if (traits.length % 2 != 0) revert TraitsMustBePairs();
Achievement memory old = _achievements[achievementID];
bytes memory existing = SSTORE2.read(old.image);
if (_isDifferent(existing, image)) {
_achievements[achievementID].image = SSTORE2.write(image);
}
if (_isDifferent(bytes(old.name), bytes(name))) {
_achievements[achievementID].name = name;
}
if (_isDifferent(bytes(old.description), bytes(description))) {
_achievements[achievementID].description = description;
}
while (_achievements[achievementID].traits.length > traits.length) {
// Remove traits from existing list if the new trait list is shorter
_achievements[achievementID].traits.pop();
}
uint256 i = 0;
while (i < _achievements[achievementID].traits.length) {
// Set the new keys and values if they changed of slots that already exist
if (_isDifferent(bytes(_achievements[achievementID].traits[i]), bytes(traits[i]))) {
_achievements[achievementID].traits[i] = traits[i];
}
if (_isDifferent(bytes(_achievements[achievementID].traits[i + 1]), bytes(traits[i + 1]))) {
_achievements[achievementID].traits[i + 1] = traits[i + 1];
}
i = i + 2;
}
while (i < traits.length) {
// Add new traits if the new trait list is longer
_achievements[achievementID].traits.push(traits[i]);
_achievements[achievementID].traits.push(traits[i + 1]);
i = i + 2;
}
}
function _isDifferent(bytes memory a, bytes memory b) internal pure returns (bool) {
return a.length != b.length || keccak256(a) != keccak256(b);
}
function achievementsCount() external view returns (uint256) {
return _achievements.length;
}
function getAchievements(uint256 offset, uint256 count) external view returns (string memory) {
if (offset >= _achievements.length) revert IndexOutOfBounds();
if (offset + count > _achievements.length) revert IndexOutOfBounds();
string memory json = "[";
string memory image;
string memory attributes;
uint256 j;
uint256 i = offset;
unchecked {
uint256 end = offset + count;
while (i < end) {
Achievement memory achievement = _achievements[i];
image = _getImage(achievement.image);
attributes = "";
j = 0;
while (j < achievement.traits.length) {
if (keccak256(abi.encodePacked(achievement.traits[j])) != keccak256(abi.encodePacked(""))) {
attributes = string.concat(
attributes, _buildMetadata(achievement.traits[j], achievement.traits[j + 1]), ","
);
}
j = j + 2;
}
attributes = string.concat(attributes, _buildMetadata("name", achievement.name));
string memory achievementJson = string.concat(
'{"name": "',
achievement.name,
'", "id":',
LibString.toString(i),
', "description":"',
achievement.description,
'","image":"data:image/svg+xml;base64,',
image,
'","attributes": [',
attributes,
"]}"
);
json = string.concat(json, achievementJson);
if (i != end - 1) {
json = string.concat(json, ",");
}
++i;
}
}
json = string.concat(json, "]");
return json;
}
function claim(uint256 achievementID, bytes memory signature) public {
if (!isOpen) revert ClaimClosed();
if (!_isValidPayload(achievementID, signature)) revert InvalidPayload();
if (_achievements.length <= achievementID) revert IndexOutOfBounds();
bytes32 msgHash = keccak256(abi.encodePacked(msg.sender, achievementID));
if (_claimed[msgHash]) revert AlreadyClaimed();
_claimed[msgHash] = true;
_tokens.push(achievementID);
_mint(msg.sender);
}
function tokenURI(uint256 tokenID) public view virtual override(IERC721Metadata) returns (string memory) {
if (!_exists(tokenID)) revert TokenDoesNotExist();
Achievement memory achievement = _achievements[_tokens[tokenID]];
string memory image = _getImage(achievement.image);
string memory animationURL = string.concat('"data:image/svg+xml;base64,', image, '",');
if (useExternalURI) {
if (bytes(externalURI).length == 0) revert InvalidExternalURI();
animationURL = string.concat('"', externalURI, LibString.toString(tokenID), '",');
}
string memory attributes = "";
uint256 i = 0;
while (i < achievement.traits.length) {
if (keccak256(abi.encodePacked(achievement.traits[i])) != keccak256(abi.encodePacked(""))) {
attributes =
string.concat(attributes, _buildMetadata(achievement.traits[i], achievement.traits[i + 1]), ",");
}
i = i + 2;
}
attributes = string.concat(attributes, _buildMetadata("name", achievement.name));
bytes memory json = abi.encodePacked(
'{"name": "',
achievement.name,
'", "description":"',
achievement.description,
'","image":"data:image/svg+xml;base64,',
image,
'","animation_url":',
animationURL,
'"attributes": [',
attributes,
"]}"
);
return string(abi.encodePacked("data:application/json,", json));
}
function _getImage(address image) internal view returns (string memory) {
return Base64.encode(
abi.encodePacked(
'<svg width="100%" height="100%" viewBox="0 0 20000 20000" xmlns="http://www.w3.org/2000/svg">',
"<style>svg{background-color:transparent;background-image:url(data:image/png;base64,",
Base64.encode(SSTORE2.read(image)),
");background-repeat:no-repeat;background-size:contain;background-position:center;image-rendering:-webkit-optimize-contrast;-ms-interpolation-mode:nearest-neighbor;image-rendering:-moz-crisp-edges;image-rendering:pixelated;}</style></svg>"
)
);
}
function _isValidPayload(uint256 tokenID, bytes memory signature) internal view returns (bool) {
if (_offchainSigner == address(0)) {
revert InvalidOffchainSigner();
}
bytes32 msgHash = keccak256(abi.encodePacked(msg.sender, tokenID));
bytes32 signedHash = keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", msgHash));
return signedHash.recover(signature) == _offchainSigner;
}
}
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.20;
interface ILeetCollective {
function nameOf(address member) external view returns (string memory);
function roleOf(address member) external view returns (uint16);
function roleNameOf(address member) external view returns (string memory);
}
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.20;
import {ILeetCollective} from "./ILeetCollective.sol";
import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
abstract contract LeetCollectiveGuarded is Ownable {
ILeetCollective internal _collective;
error Unauthorized();
constructor(address collective) {
_collective = ILeetCollective(collective);
}
function leetCollectiveAddress() public view returns (address) {
return address(_collective);
}
function setLeetCollective(address collective) external serOrOwner {
_collective = ILeetCollective(collective);
}
modifier serOrOwner() {
uint16 role = _collective.roleOf(msg.sender);
if (role != 532 && owner() != msg.sender) revert Unauthorized();
_;
}
modifier onlySer() {
uint16 role = _collective.roleOf(msg.sender);
if (role != 532) revert Unauthorized();
_;
}
modifier serOrForce() {
uint16 role = _collective.roleOf(msg.sender);
if (role != 532 && role != 1337) revert Unauthorized();
_;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import {IERC721} from "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import {IERC721Receiver} from "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
import {IERC721Metadata} from "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
import {IERC721Enumerable} from "@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol";
import {IERC165, ERC165} from "@openzeppelin/contracts/utils/introspection/ERC165.sol";
abstract contract ERC721L is ERC165, IERC721, IERC721Metadata, IERC721Enumerable {
// =============================================================
// Fields
// =============================================================
string private _name;
string private _description;
string private _symbol;
// Mapping from token ID to owner address
address[] internal _owners;
mapping(uint256 => address) private _tokenApprovals;
mapping(address => mapping(address => bool)) private _operatorApprovals;
// =============================================================
// Errors
// =============================================================
error TokenDoesNotExist();
error TokenAlreadyMinted();
error NotAllowedToMint();
error NotTokenOwnerNorApproved();
error NotTokenOwner();
error TokenOwner();
error ZeroAddressInvalidArgument();
error NotAllowedToApprove();
error IndexOutOfBounds();
error TransferToNonERC721Receiver();
constructor(string memory name_, string memory symbol_, string memory description_) {
_name = name_;
_description = description_;
_symbol = symbol_;
}
// =============================================================
// Opensea
// =============================================================
function contractURI() public view returns (string memory) {
string memory json = string.concat('{"name": "', _name, '","description":"', _description, '"}');
return string.concat("data:application/json;utf8,", json);
}
// =============================================================
// IERC721
// =============================================================
function balanceOf(address owner) public view virtual override returns (uint256) {
if (owner == address(0)) revert ZeroAddressInvalidArgument();
uint256 count;
uint256 i;
do {
if (owner == _owners[i]) ++count;
++i;
} while (i < _owners.length);
return count;
}
function ownerOf(uint256 tokenId) public view virtual override returns (address) {
if (_owners.length <= tokenId) revert TokenDoesNotExist();
address owner = _owners[tokenId];
if (owner == address(0)) revert TokenDoesNotExist();
return owner;
}
function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public virtual override {
_checkApprovedOrOwner(tokenId);
ERC721L.transferFrom(from, to, tokenId);
// Check that `to` is an ERC721Receiver if it is a contract
uint256 size;
assembly {
// This opcode returns the size of the code on an address.
// It is 0 for external accounts (non-contracts)
size := extcodesize(to)
}
if (size > 0) {
try IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data) returns (bytes4 retval) {
if (retval != IERC721Receiver.onERC721Received.selector) {
revert TransferToNonERC721Receiver();
}
} catch (bytes memory reason) {
if (reason.length == 0) {
revert TransferToNonERC721Receiver();
} else {
assembly {
revert(add(32, reason), mload(reason))
}
}
}
}
}
function safeTransferFrom(address from, address to, uint256 tokenId) public virtual override {
safeTransferFrom(from, to, tokenId, "");
}
function transferFrom(address from, address to, uint256 tokenId) public virtual override {
_checkApprovedOrOwner(tokenId);
if (_owners[tokenId] != from) revert NotTokenOwner();
if (to == address(0)) revert ZeroAddressInvalidArgument();
// Clear approvals from the previous owner
delete _tokenApprovals[tokenId];
_owners[tokenId] = to;
emit Transfer(from, to, tokenId);
}
function approve(address to, uint256 tokenId) public virtual override {
address owner = _owners[tokenId];
if (owner == to) revert TokenOwner();
if (msg.sender != owner && !isApprovedForAll(owner, msg.sender)) {
revert NotTokenOwnerNorApproved();
}
_tokenApprovals[tokenId] = to;
emit Approval(owner, to, tokenId);
}
function setApprovalForAll(address operator, bool approved) public virtual override {
if (operator == msg.sender) revert NotAllowedToApprove();
_operatorApprovals[msg.sender][operator] = approved;
emit ApprovalForAll(msg.sender, operator, approved);
}
function getApproved(uint256 tokenId) public view virtual override returns (address) {
if (_owners[tokenId] == address(0)) revert TokenDoesNotExist();
return _tokenApprovals[tokenId];
}
function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
return _operatorApprovals[owner][operator];
}
// =============================================================
// IERC165
// =============================================================
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
return interfaceId == type(IERC721).interfaceId || interfaceId == type(IERC721Metadata).interfaceId
|| super.supportsInterface(interfaceId);
}
// =============================================================
// IERC721Metadata
// =============================================================
function name() public view virtual override returns (string memory) {
return _name;
}
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
// =============================================================
// IERC721Enumerable
// =============================================================
function totalSupply() public view virtual override returns (uint256) {
return _owners.length;
}
function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
if (index >= _owners.length) revert IndexOutOfBounds();
return index;
}
function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256 tokenId) {
if (index >= _owners.length) revert IndexOutOfBounds();
uint256 count;
uint256 i;
do {
if (owner == _owners[i]) {
if (count == index) return i;
++count;
}
++i;
} while (i < _owners.length);
revert IndexOutOfBounds();
}
// =============================================================
// Internal
// =============================================================
function _exists(uint256 tokenId) internal view virtual returns (bool) {
return tokenId < _owners.length && _owners[tokenId] != address(0);
}
function _checkApprovedOrOwner(uint256 tokenId) internal view virtual {
address owner = ERC721L.ownerOf(tokenId);
if (!(msg.sender == owner || getApproved(tokenId) == msg.sender || isApprovedForAll(owner, msg.sender))) {
revert NotTokenOwnerNorApproved();
}
}
/*
* @notice Add a new token without minting it
*/
function _add() internal virtual {
_owners.push();
}
function _mint(address to) internal virtual returns (uint256 tokenId) {
if (to == address(0)) revert ZeroAddressInvalidArgument();
tokenId = _owners.length;
_owners.push(to);
emit Transfer(address(0), to, tokenId);
}
function _mintToken(address to, uint256 tokenId) internal virtual {
if (to == address(0)) revert ZeroAddressInvalidArgument();
if (_owners.length <= tokenId) revert TokenDoesNotExist();
if (_owners[tokenId] != address(0)) revert TokenAlreadyMinted();
_owners[tokenId] = to;
emit Transfer(address(0), to, tokenId);
}
function _burn(uint256 tokenId) internal virtual {
address owner = _owners[tokenId];
delete _tokenApprovals[tokenId];
_owners[tokenId] = address(0);
emit Transfer(owner, address(0), tokenId);
}
function _buildMetadata(string memory key, string memory value) internal pure returns (string memory trait) {
return string.concat('{"trait_type":"', key, '","value": "', value, '"}');
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
/// @notice Library to encode strings in Base64.
/// @author Solady (https://github.com/vectorized/solady/blob/main/src/utils/Base64.sol)
/// @author Modified from Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/Base64.sol)
/// @author Modified from (https://github.com/Brechtpd/base64/blob/main/base64.sol) by Brecht Devos - <[email protected]>.
library Base64 {
/// @dev Encodes `data` using the base64 encoding described in RFC 4648.
/// See: https://datatracker.ietf.org/doc/html/rfc4648
/// @param fileSafe Whether to replace '+' with '-' and '/' with '_'.
/// @param noPadding Whether to strip away the padding.
function encode(bytes memory data, bool fileSafe, bool noPadding)
internal
pure
returns (string memory result)
{
/// @solidity memory-safe-assembly
assembly {
let dataLength := mload(data)
if dataLength {
// Multiply by 4/3 rounded up.
// The `shl(2, ...)` is equivalent to multiplying by 4.
let encodedLength := shl(2, div(add(dataLength, 2), 3))
// Set `result` to point to the start of the free memory.
result := mload(0x40)
// Store the table into the scratch space.
// Offsetted by -1 byte so that the `mload` will load the character.
// We will rewrite the free memory pointer at `0x40` later with
// the allocated size.
// The magic constant 0x0670 will turn "-_" into "+/".
mstore(0x1f, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdef")
mstore(0x3f, xor("ghijklmnopqrstuvwxyz0123456789-_", mul(iszero(fileSafe), 0x0670)))
// Skip the first slot, which stores the length.
let ptr := add(result, 0x20)
let end := add(ptr, encodedLength)
// Run over the input, 3 bytes at a time.
for {} 1 {} {
data := add(data, 3) // Advance 3 bytes.
let input := mload(data)
// Write 4 bytes. Optimized for fewer stack operations.
mstore8(0, mload(and(shr(18, input), 0x3F)))
mstore8(1, mload(and(shr(12, input), 0x3F)))
mstore8(2, mload(and(shr(6, input), 0x3F)))
mstore8(3, mload(and(input, 0x3F)))
mstore(ptr, mload(0x00))
ptr := add(ptr, 4) // Advance 4 bytes.
if iszero(lt(ptr, end)) { break }
}
mstore(0x40, add(end, 0x20)) // Allocate the memory.
// Equivalent to `o = [0, 2, 1][dataLength % 3]`.
let o := div(2, mod(dataLength, 3))
// Offset `ptr` and pad with '='. We can simply write over the end.
mstore(sub(ptr, o), shl(240, 0x3d3d))
// Set `o` to zero if there is padding.
o := mul(iszero(iszero(noPadding)), o)
mstore(sub(ptr, o), 0) // Zeroize the slot after the string.
mstore(result, sub(encodedLength, o)) // Store the length.
}
}
}
/// @dev Encodes `data` using the base64 encoding described in RFC 4648.
/// Equivalent to `encode(data, false, false)`.
function encode(bytes memory data) internal pure returns (string memory result) {
result = encode(data, false, false);
}
/// @dev Encodes `data` using the base64 encoding described in RFC 4648.
/// Equivalent to `encode(data, fileSafe, false)`.
function encode(bytes memory data, bool fileSafe)
internal
pure
returns (string memory result)
{
result = encode(data, fileSafe, false);
}
/// @dev Decodes base64 encoded `data`.
///
/// Supports:
/// - RFC 4648 (both standard and file-safe mode).
/// - RFC 3501 (63: ',').
///
/// Does not support:
/// - Line breaks.
///
/// Note: For performance reasons,
/// this function will NOT revert on invalid `data` inputs.
/// Outputs for invalid inputs will simply be undefined behaviour.
/// It is the user's responsibility to ensure that the `data`
/// is a valid base64 encoded string.
function decode(string memory data) internal pure returns (bytes memory result) {
/// @solidity memory-safe-assembly
assembly {
let dataLength := mload(data)
if dataLength {
let decodedLength := mul(shr(2, dataLength), 3)
for {} 1 {} {
// If padded.
if iszero(and(dataLength, 3)) {
let t := xor(mload(add(data, dataLength)), 0x3d3d)
// forgefmt: disable-next-item
decodedLength := sub(
decodedLength,
add(iszero(byte(30, t)), iszero(byte(31, t)))
)
break
}
// If non-padded.
decodedLength := add(decodedLength, sub(and(dataLength, 3), 1))
break
}
result := mload(0x40)
// Write the length of the bytes.
mstore(result, decodedLength)
// Skip the first slot, which stores the length.
let ptr := add(result, 0x20)
let end := add(ptr, decodedLength)
// Load the table into the scratch space.
// Constants are optimized for smaller bytecode with zero gas overhead.
// `m` also doubles as the mask of the upper 6 bits.
let m := 0xfc000000fc00686c7074787c8084888c9094989ca0a4a8acb0b4b8bcc0c4c8cc
mstore(0x5b, m)
mstore(0x3b, 0x04080c1014181c2024282c3034383c4044484c5054585c6064)
mstore(0x1a, 0xf8fcf800fcd0d4d8dce0e4e8ecf0f4)
for {} 1 {} {
// Read 4 bytes.
data := add(data, 4)
let input := mload(data)
// Write 3 bytes.
// forgefmt: disable-next-item
mstore(ptr, or(
and(m, mload(byte(28, input))),
shr(6, or(
and(m, mload(byte(29, input))),
shr(6, or(
and(m, mload(byte(30, input))),
shr(6, mload(byte(31, input)))
))
))
))
ptr := add(ptr, 3)
if iszero(lt(ptr, end)) { break }
}
mstore(0x40, add(end, 0x20)) // Allocate the memory.
mstore(end, 0) // Zeroize the slot after the bytes.
mstore(0x60, 0) // Restore the zero slot.
}
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
/// @notice Library for converting numbers into strings and other string operations.
/// @author Solady (https://github.com/vectorized/solady/blob/main/src/utils/LibString.sol)
/// @author Modified from Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/LibString.sol)
library LibString {
/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/* CUSTOM ERRORS */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
/// @dev The `length` of the output is too small to contain all the hex digits.
error HexLengthInsufficient();
/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/* CONSTANTS */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
/// @dev The constant returned when the `search` is not found in the string.
uint256 internal constant NOT_FOUND = type(uint256).max;
/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/* DECIMAL OPERATIONS */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
/// @dev Returns the base 10 decimal representation of `value`.
function toString(uint256 value) internal pure returns (string memory str) {
/// @solidity memory-safe-assembly
assembly {
// The maximum value of a uint256 contains 78 digits (1 byte per digit), but
// we allocate 0xa0 bytes to keep the free memory pointer 32-byte word aligned.
// We will need 1 word for the trailing zeros padding, 1 word for the length,
// and 3 words for a maximum of 78 digits.
str := add(mload(0x40), 0x80)
// Update the free memory pointer to allocate.
mstore(0x40, add(str, 0x20))
// Zeroize the slot after the string.
mstore(str, 0)
// Cache the end of the memory to calculate the length later.
let end := str
let w := not(0) // Tsk.
// We write the string from rightmost digit to leftmost digit.
// The following is essentially a do-while loop that also handles the zero case.
for { let temp := value } 1 {} {
str := add(str, w) // `sub(str, 1)`.
// Write the character to the pointer.
// The ASCII index of the '0' character is 48.
mstore8(str, add(48, mod(temp, 10)))
// Keep dividing `temp` until zero.
temp := div(temp, 10)
if iszero(temp) { break }
}
let length := sub(end, str)
// Move the pointer 32 bytes leftwards to make room for the length.
str := sub(str, 0x20)
// Store the length.
mstore(str, length)
}
}
/// @dev Returns the base 10 decimal representation of `value`.
function toString(int256 value) internal pure returns (string memory str) {
if (value >= 0) {
return toString(uint256(value));
}
unchecked {
str = toString(uint256(-value));
}
/// @solidity memory-safe-assembly
assembly {
// We still have some spare memory space on the left,
// as we have allocated 3 words (96 bytes) for up to 78 digits.
let length := mload(str) // Load the string length.
mstore(str, 0x2d) // Store the '-' character.
str := sub(str, 1) // Move back the string pointer by a byte.
mstore(str, add(length, 1)) // Update the string length.
}
}
/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/* HEXADECIMAL OPERATIONS */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
/// @dev Returns the hexadecimal representation of `value`,
/// left-padded to an input length of `length` bytes.
/// The output is prefixed with "0x" encoded using 2 hexadecimal digits per byte,
/// giving a total length of `length * 2 + 2` bytes.
/// Reverts if `length` is too small for the output to contain all the digits.
function toHexString(uint256 value, uint256 length) internal pure returns (string memory str) {
str = toHexStringNoPrefix(value, length);
/// @solidity memory-safe-assembly
assembly {
let strLength := add(mload(str), 2) // Compute the length.
mstore(str, 0x3078) // Write the "0x" prefix.
str := sub(str, 2) // Move the pointer.
mstore(str, strLength) // Write the length.
}
}
/// @dev Returns the hexadecimal representation of `value`,
/// left-padded to an input length of `length` bytes.
/// The output is prefixed with "0x" encoded using 2 hexadecimal digits per byte,
/// giving a total length of `length * 2` bytes.
/// Reverts if `length` is too small for the output to contain all the digits.
function toHexStringNoPrefix(uint256 value, uint256 length)
internal
pure
returns (string memory str)
{
/// @solidity memory-safe-assembly
assembly {
// We need 0x20 bytes for the trailing zeros padding, `length * 2` bytes
// for the digits, 0x02 bytes for the prefix, and 0x20 bytes for the length.
// We add 0x20 to the total and round down to a multiple of 0x20.
// (0x20 + 0x20 + 0x02 + 0x20) = 0x62.
str := add(mload(0x40), and(add(shl(1, length), 0x42), not(0x1f)))
// Allocate the memory.
mstore(0x40, add(str, 0x20))
// Zeroize the slot after the string.
mstore(str, 0)
// Cache the end to calculate the length later.
let end := str
// Store "0123456789abcdef" in scratch space.
mstore(0x0f, 0x30313233343536373839616263646566)
let start := sub(str, add(length, length))
let w := not(1) // Tsk.
let temp := value
// We write the string from rightmost digit to leftmost digit.
// The following is essentially a do-while loop that also handles the zero case.
for {} 1 {} {
str := add(str, w) // `sub(str, 2)`.
mstore8(add(str, 1), mload(and(temp, 15)))
mstore8(str, mload(and(shr(4, temp), 15)))
temp := shr(8, temp)
if iszero(xor(str, start)) { break }
}
if temp {
// Store the function selector of `HexLengthInsufficient()`.
mstore(0x00, 0x2194895a)
// Revert with (offset, size).
revert(0x1c, 0x04)
}
// Compute the string's length.
let strLength := sub(end, str)
// Move the pointer and write the length.
str := sub(str, 0x20)
mstore(str, strLength)
}
}
/// @dev Returns the hexadecimal representation of `value`.
/// The output is prefixed with "0x" and encoded using 2 hexadecimal digits per byte.
/// As address are 20 bytes long, the output will left-padded to have
/// a length of `20 * 2 + 2` bytes.
function toHexString(uint256 value) internal pure returns (string memory str) {
str = toHexStringNoPrefix(value);
/// @solidity memory-safe-assembly
assembly {
let strLength := add(mload(str), 2) // Compute the length.
mstore(str, 0x3078) // Write the "0x" prefix.
str := sub(str, 2) // Move the pointer.
mstore(str, strLength) // Write the length.
}
}
/// @dev Returns the hexadecimal representation of `value`.
/// The output is prefixed with "0x".
/// The output excludes leading "0" from the `toHexString` output.
/// `0x00: "0x0", 0x01: "0x1", 0x12: "0x12", 0x123: "0x123"`.
function toMinimalHexString(uint256 value) internal pure returns (string memory str) {
str = toHexStringNoPrefix(value);
/// @solidity memory-safe-assembly
assembly {
let o := eq(byte(0, mload(add(str, 0x20))), 0x30) // Whether leading zero is present.
let strLength := add(mload(str), 2) // Compute the length.
mstore(add(str, o), 0x3078) // Write the "0x" prefix, accounting for leading zero.
str := sub(add(str, o), 2) // Move the pointer, accounting for leading zero.
mstore(str, sub(strLength, o)) // Write the length, accounting for leading zero.
}
}
/// @dev Returns the hexadecimal representation of `value`.
/// The output excludes leading "0" from the `toHexStringNoPrefix` output.
/// `0x00: "0", 0x01: "1", 0x12: "12", 0x123: "123"`.
function toMinimalHexStringNoPrefix(uint256 value) internal pure returns (string memory str) {
str = toHexStringNoPrefix(value);
/// @solidity memory-safe-assembly
assembly {
let o := eq(byte(0, mload(add(str, 0x20))), 0x30) // Whether leading zero is present.
let strLength := mload(str) // Get the length.
str := add(str, o) // Move the pointer, accounting for leading zero.
mstore(str, sub(strLength, o)) // Write the length, accounting for leading zero.
}
}
/// @dev Returns the hexadecimal representation of `value`.
/// The output is encoded using 2 hexadecimal digits per byte.
/// As address are 20 bytes long, the output will left-padded to have
/// a length of `20 * 2` bytes.
function toHexStringNoPrefix(uint256 value) internal pure returns (string memory str) {
/// @solidity memory-safe-assembly
assembly {
// We need 0x20 bytes for the trailing zeros padding, 0x20 bytes for the length,
// 0x02 bytes for the prefix, and 0x40 bytes for the digits.
// The next multiple of 0x20 above (0x20 + 0x20 + 0x02 + 0x40) is 0xa0.
str := add(mload(0x40), 0x80)
// Allocate the memory.
mstore(0x40, add(str, 0x20))
// Zeroize the slot after the string.
mstore(str, 0)
// Cache the end to calculate the length later.
let end := str
// Store "0123456789abcdef" in scratch space.
mstore(0x0f, 0x30313233343536373839616263646566)
let w := not(1) // Tsk.
// We write the string from rightmost digit to leftmost digit.
// The following is essentially a do-while loop that also handles the zero case.
for { let temp := value } 1 {} {
str := add(str, w) // `sub(str, 2)`.
mstore8(add(str, 1), mload(and(temp, 15)))
mstore8(str, mload(and(shr(4, temp), 15)))
temp := shr(8, temp)
if iszero(temp) { break }
}
// Compute the string's length.
let strLength := sub(end, str)
// Move the pointer and write the length.
str := sub(str, 0x20)
mstore(str, strLength)
}
}
/// @dev Returns the hexadecimal representation of `value`.
/// The output is prefixed with "0x", encoded using 2 hexadecimal digits per byte,
/// and the alphabets are capitalized conditionally according to
/// https://eips.ethereum.org/EIPS/eip-55
function toHexStringChecksummed(address value) internal pure returns (string memory str) {
str = toHexString(value);
/// @solidity memory-safe-assembly
assembly {
let mask := shl(6, div(not(0), 255)) // `0b010000000100000000 ...`
let o := add(str, 0x22)
let hashed := and(keccak256(o, 40), mul(34, mask)) // `0b10001000 ... `
let t := shl(240, 136) // `0b10001000 << 240`
for { let i := 0 } 1 {} {
mstore(add(i, i), mul(t, byte(i, hashed)))
i := add(i, 1)
if eq(i, 20) { break }
}
mstore(o, xor(mload(o), shr(1, and(mload(0x00), and(mload(o), mask)))))
o := add(o, 0x20)
mstore(o, xor(mload(o), shr(1, and(mload(0x20), and(mload(o), mask)))))
}
}
/// @dev Returns the hexadecimal representation of `value`.
/// The output is prefixed with "0x" and encoded using 2 hexadecimal digits per byte.
function toHexString(address value) internal pure returns (string memory str) {
str = toHexStringNoPrefix(value);
/// @solidity memory-safe-assembly
assembly {
let strLength := add(mload(str), 2) // Compute the length.
mstore(str, 0x3078) // Write the "0x" prefix.
str := sub(str, 2) // Move the pointer.
mstore(str, strLength) // Write the length.
}
}
/// @dev Returns the hexadecimal representation of `value`.
/// The output is encoded using 2 hexadecimal digits per byte.
function toHexStringNoPrefix(address value) internal pure returns (string memory str) {
/// @solidity memory-safe-assembly
assembly {
str := mload(0x40)
// Allocate the memory.
// We need 0x20 bytes for the trailing zeros padding, 0x20 bytes for the length,
// 0x02 bytes for the prefix, and 0x28 bytes for the digits.
// The next multiple of 0x20 above (0x20 + 0x20 + 0x02 + 0x28) is 0x80.
mstore(0x40, add(str, 0x80))
// Store "0123456789abcdef" in scratch space.
mstore(0x0f, 0x30313233343536373839616263646566)
str := add(str, 2)
mstore(str, 40)
let o := add(str, 0x20)
mstore(add(o, 40), 0)
value := shl(96, value)
// We write the string from rightmost digit to leftmost digit.
// The following is essentially a do-while loop that also handles the zero case.
for { let i := 0 } 1 {} {
let p := add(o, add(i, i))
let temp := byte(i, value)
mstore8(add(p, 1), mload(and(temp, 15)))
mstore8(p, mload(shr(4, temp)))
i := add(i, 1)
if eq(i, 20) { break }
}
}
}
/// @dev Returns the hex encoded string from the raw bytes.
/// The output is encoded using 2 hexadecimal digits per byte.
function toHexString(bytes memory raw) internal pure returns (string memory str) {
str = toHexStringNoPrefix(raw);
/// @solidity memory-safe-assembly
assembly {
let strLength := add(mload(str), 2) // Compute the length.
mstore(str, 0x3078) // Write the "0x" prefix.
str := sub(str, 2) // Move the pointer.
mstore(str, strLength) // Write the length.
}
}
/// @dev Returns the hex encoded string from the raw bytes.
/// The output is encoded using 2 hexadecimal digits per byte.
function toHexStringNoPrefix(bytes memory raw) internal pure returns (string memory str) {
/// @solidity memory-safe-assembly
assembly {
let length := mload(raw)
str := add(mload(0x40), 2) // Skip 2 bytes for the optional prefix.
mstore(str, add(length, length)) // Store the length of the output.
// Store "0123456789abcdef" in scratch space.
mstore(0x0f, 0x30313233343536373839616263646566)
let o := add(str, 0x20)
let end := add(raw, length)
for {} iszero(eq(raw, end)) {} {
raw := add(raw, 1)
mstore8(add(o, 1), mload(and(mload(raw), 15)))
mstore8(o, mload(and(shr(4, mload(raw)), 15)))
o := add(o, 2)
}
mstore(o, 0) // Zeroize the slot after the string.
mstore(0x40, add(o, 0x20)) // Allocate the memory.
}
}
/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/* RUNE STRING OPERATIONS */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
/// @dev Returns the number of UTF characters in the string.
function runeCount(string memory s) internal pure returns (uint256 result) {
/// @solidity memory-safe-assembly
assembly {
if mload(s) {
mstore(0x00, div(not(0), 255))
mstore(0x20, 0x0202020202020202020202020202020202020202020202020303030304040506)
let o := add(s, 0x20)
let end := add(o, mload(s))
for { result := 1 } 1 { result := add(result, 1) } {
o := add(o, byte(0, mload(shr(250, mload(o)))))
if iszero(lt(o, end)) { break }
}
}
}
}
/// @dev Returns if this string is a 7-bit ASCII string.
/// (i.e. all characters codes are in [0..127])
function is7BitASCII(string memory s) internal pure returns (bool result) {
/// @solidity memory-safe-assembly
assembly {
let mask := shl(7, div(not(0), 255))
result := 1
let n := mload(s)
if n {
let o := add(s, 0x20)
let end := add(o, n)
let last := mload(end)
mstore(end, 0)
for {} 1 {} {
if and(mask, mload(o)) {
result := 0
break
}
o := add(o, 0x20)
if iszero(lt(o, end)) { break }
}
mstore(end, last)
}
}
}
/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/* BYTE STRING OPERATIONS */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
// For performance and bytecode compactness, all indices of the following operations
// are byte (ASCII) offsets, not UTF character offsets.
/// @dev Returns `subject` all occurrences of `search` replaced with `replacement`.
function replace(string memory subject, string memory search, string memory replacement)
internal
pure
returns (string memory result)
{
/// @solidity memory-safe-assembly
assembly {
let subjectLength := mload(subject)
let searchLength := mload(search)
let replacementLength := mload(replacement)
subject := add(subject, 0x20)
search := add(search, 0x20)
replacement := add(replacement, 0x20)
result := add(mload(0x40), 0x20)
let subjectEnd := add(subject, subjectLength)
if iszero(gt(searchLength, subjectLength)) {
let subjectSearchEnd := add(sub(subjectEnd, searchLength), 1)
let h := 0
if iszero(lt(searchLength, 0x20)) { h := keccak256(search, searchLength) }
let m := shl(3, sub(0x20, and(searchLength, 0x1f)))
let s := mload(search)
for {} 1 {} {
let t := mload(subject)
// Whether the first `searchLength % 32` bytes of
// `subject` and `search` matches.
if iszero(shr(m, xor(t, s))) {
if h {
if iszero(eq(keccak256(subject, searchLength), h)) {
mstore(result, t)
result := add(result, 1)
subject := add(subject, 1)
if iszero(lt(subject, subjectSearchEnd)) { break }
continue
}
}
// Copy the `replacement` one word at a time.
for { let o := 0 } 1 {} {
mstore(add(result, o), mload(add(replacement, o)))
o := add(o, 0x20)
if iszero(lt(o, replacementLength)) { break }
}
result := add(result, replacementLength)
subject := add(subject, searchLength)
if searchLength {
if iszero(lt(subject, subjectSearchEnd)) { break }
continue
}
}
mstore(result, t)
result := add(result, 1)
subject := add(subject, 1)
if iszero(lt(subject, subjectSearchEnd)) { break }
}
}
let resultRemainder := result
result := add(mload(0x40), 0x20)
let k := add(sub(resultRemainder, result), sub(subjectEnd, subject))
// Copy the rest of the string one word at a time.
for {} lt(subject, subjectEnd) {} {
mstore(resultRemainder, mload(subject))
resultRemainder := add(resultRemainder, 0x20)
subject := add(subject, 0x20)
}
result := sub(result, 0x20)
let last := add(add(result, 0x20), k) // Zeroize the slot after the string.
mstore(last, 0)
mstore(0x40, add(last, 0x20)) // Allocate the memory.
mstore(result, k) // Store the length.
}
}
/// @dev Returns the byte index of the first location of `search` in `subject`,
/// searching from left to right, starting from `from`.
/// Returns `NOT_FOUND` (i.e. `type(uint256).max`) if the `search` is not found.
function indexOf(string memory subject, string memory search, uint256 from)
internal
pure
returns (uint256 result)
{
/// @solidity memory-safe-assembly
assembly {
for { let subjectLength := mload(subject) } 1 {} {
if iszero(mload(search)) {
if iszero(gt(from, subjectLength)) {
result := from
break
}
result := subjectLength
break
}
let searchLength := mload(search)
let subjectStart := add(subject, 0x20)
result := not(0) // Initialize to `NOT_FOUND`.
subject := add(subjectStart, from)
let end := add(sub(add(subjectStart, subjectLength), searchLength), 1)
let m := shl(3, sub(0x20, and(searchLength, 0x1f)))
let s := mload(add(search, 0x20))
if iszero(and(lt(subject, end), lt(from, subjectLength))) { break }
if iszero(lt(searchLength, 0x20)) {
for { let h := keccak256(add(search, 0x20), searchLength) } 1 {} {
if iszero(shr(m, xor(mload(subject), s))) {
if eq(keccak256(subject, searchLength), h) {
result := sub(subject, subjectStart)
break
}
}
subject := add(subject, 1)
if iszero(lt(subject, end)) { break }
}
break
}
for {} 1 {} {
if iszero(shr(m, xor(mload(subject), s))) {
result := sub(subject, subjectStart)
break
}
subject := add(subject, 1)
if iszero(lt(subject, end)) { break }
}
break
}
}
}
/// @dev Returns the byte index of the first location of `search` in `subject`,
/// searching from left to right.
/// Returns `NOT_FOUND` (i.e. `type(uint256).max`) if the `search` is not found.
function indexOf(string memory subject, string memory search)
internal
pure
returns (uint256 result)
{
result = indexOf(subject, search, 0);
}
/// @dev Returns the byte index of the first location of `search` in `subject`,
/// searching from right to left, starting from `from`.
/// Returns `NOT_FOUND` (i.e. `type(uint256).max`) if the `search` is not found.
function lastIndexOf(string memory subject, string memory search, uint256 from)
internal
pure
returns (uint256 result)
{
/// @solidity memory-safe-assembly
assembly {
for {} 1 {} {
result := not(0) // Initialize to `NOT_FOUND`.
let searchLength := mload(search)
if gt(searchLength, mload(subject)) { break }
let w := result
let fromMax := sub(mload(subject), searchLength)
if iszero(gt(fromMax, from)) { from := fromMax }
let end := add(add(subject, 0x20), w)
subject := add(add(subject, 0x20), from)
if iszero(gt(subject, end)) { break }
// As this function is not too often used,
// we shall simply use keccak256 for smaller bytecode size.
for { let h := keccak256(add(search, 0x20), searchLength) } 1 {} {
if eq(keccak256(subject, searchLength), h) {
result := sub(subject, add(end, 1))
break
}
subject := add(subject, w) // `sub(subject, 1)`.
if iszero(gt(subject, end)) { break }
}
break
}
}
}
/// @dev Returns the byte index of the first location of `search` in `subject`,
/// searching from right to left.
/// Returns `NOT_FOUND` (i.e. `type(uint256).max`) if the `search` is not found.
function lastIndexOf(string memory subject, string memory search)
internal
pure
returns (uint256 result)
{
result = lastIndexOf(subject, search, uint256(int256(-1)));
}
/// @dev Returns whether `subject` starts with `search`.
function startsWith(string memory subject, string memory search)
internal
pure
returns (bool result)
{
/// @solidity memory-safe-assembly
assembly {
let searchLength := mload(search)
// Just using keccak256 directly is actually cheaper.
// forgefmt: disable-next-item
result := and(
iszero(gt(searchLength, mload(subject))),
eq(
keccak256(add(subject, 0x20), searchLength),
keccak256(add(search, 0x20), searchLength)
)
)
}
}
/// @dev Returns whether `subject` ends with `search`.
function endsWith(string memory subject, string memory search)
internal
pure
returns (bool result)
{
/// @solidity memory-safe-assembly
assembly {
let searchLength := mload(search)
let subjectLength := mload(subject)
// Whether `search` is not longer than `subject`.
let withinRange := iszero(gt(searchLength, subjectLength))
// Just using keccak256 directly is actually cheaper.
// forgefmt: disable-next-item
result := and(
withinRange,
eq(
keccak256(
// `subject + 0x20 + max(subjectLength - searchLength, 0)`.
add(add(subject, 0x20), mul(withinRange, sub(subjectLength, searchLength))),
searchLength
),
keccak256(add(search, 0x20), searchLength)
)
)
}
}
/// @dev Returns `subject` repeated `times`.
function repeat(string memory subject, uint256 times)
internal
pure
returns (string memory result)
{
/// @solidity memory-safe-assembly
assembly {
let subjectLength := mload(subject)
if iszero(or(iszero(times), iszero(subjectLength))) {
subject := add(subject, 0x20)
result := mload(0x40)
let output := add(result, 0x20)
for {} 1 {} {
// Copy the `subject` one word at a time.
for { let o := 0 } 1 {} {
mstore(add(output, o), mload(add(subject, o)))
o := add(o, 0x20)
if iszero(lt(o, subjectLength)) { break }
}
output := add(output, subjectLength)
times := sub(times, 1)
if iszero(times) { break }
}
mstore(output, 0) // Zeroize the slot after the string.
let resultLength := sub(output, add(result, 0x20))
mstore(result, resultLength) // Store the length.
// Allocate the memory.
mstore(0x40, add(result, add(resultLength, 0x20)))
}
}
}
/// @dev Returns a copy of `subject` sliced from `start` to `end` (exclusive).
/// `start` and `end` are byte offsets.
function slice(string memory subject, uint256 start, uint256 end)
internal
pure
returns (string memory result)
{
/// @solidity memory-safe-assembly
assembly {
let subjectLength := mload(subject)
if iszero(gt(subjectLength, end)) { end := subjectLength }
if iszero(gt(subjectLength, start)) { start := subjectLength }
if lt(start, end) {
result := mload(0x40)
let resultLength := sub(end, start)
mstore(result, resultLength)
subject := add(subject, start)
let w := not(0x1f)
// Copy the `subject` one word at a time, backwards.
for { let o := and(add(resultLength, 0x1f), w) } 1 {} {
mstore(add(result, o), mload(add(subject, o)))
o := add(o, w) // `sub(o, 0x20)`.
if iszero(o) { break }
}
// Zeroize the slot after the string.
mstore(add(add(result, 0x20), resultLength), 0)
// Allocate memory for the length and the bytes,
// rounded up to a multiple of 32.
mstore(0x40, add(result, and(add(resultLength, 0x3f), w)))
}
}
}
/// @dev Returns a copy of `subject` sliced from `start` to the end of the string.
/// `start` is a byte offset.
function slice(string memory subject, uint256 start)
internal
pure
returns (string memory result)
{
result = slice(subject, start, uint256(int256(-1)));
}
/// @dev Returns all the indices of `search` in `subject`.
/// The indices are byte offsets.
function indicesOf(string memory subject, string memory search)
internal
pure
returns (uint256[] memory result)
{
/// @solidity memory-safe-assembly
assembly {
let subjectLength := mload(subject)
let searchLength := mload(search)
if iszero(gt(searchLength, subjectLength)) {
subject := add(subject, 0x20)
search := add(search, 0x20)
result := add(mload(0x40), 0x20)
let subjectStart := subject
let subjectSearchEnd := add(sub(add(subject, subjectLength), searchLength), 1)
let h := 0
if iszero(lt(searchLength, 0x20)) { h := keccak256(search, searchLength) }
let m := shl(3, sub(0x20, and(searchLength, 0x1f)))
let s := mload(search)
for {} 1 {} {
let t := mload(subject)
// Whether the first `searchLength % 32` bytes of
// `subject` and `search` matches.
if iszero(shr(m, xor(t, s))) {
if h {
if iszero(eq(keccak256(subject, searchLength), h)) {
subject := add(subject, 1)
if iszero(lt(subject, subjectSearchEnd)) { break }
continue
}
}
// Append to `result`.
mstore(result, sub(subject, subjectStart))
result := add(result, 0x20)
// Advance `subject` by `searchLength`.
subject := add(subject, searchLength)
if searchLength {
if iszero(lt(subject, subjectSearchEnd)) { break }
continue
}
}
subject := add(subject, 1)
if iszero(lt(subject, subjectSearchEnd)) { break }
}
let resultEnd := result
// Assign `result` to the free memory pointer.
result := mload(0x40)
// Store the length of `result`.
mstore(result, shr(5, sub(resultEnd, add(result, 0x20))))
// Allocate memory for result.
// We allocate one more word, so this array can be recycled for {split}.
mstore(0x40, add(resultEnd, 0x20))
}
}
}
/// @dev Returns a arrays of strings based on the `delimiter` inside of the `subject` string.
function split(string memory subject, string memory delimiter)
internal
pure
returns (string[] memory result)
{
uint256[] memory indices = indicesOf(subject, delimiter);
/// @solidity memory-safe-assembly
assembly {
let w := not(0x1f)
let indexPtr := add(indices, 0x20)
let indicesEnd := add(indexPtr, shl(5, add(mload(indices), 1)))
mstore(add(indicesEnd, w), mload(subject))
mstore(indices, add(mload(indices), 1))
let prevIndex := 0
for {} 1 {} {
let index := mload(indexPtr)
mstore(indexPtr, 0x60)
if iszero(eq(index, prevIndex)) {
let element := mload(0x40)
let elementLength := sub(index, prevIndex)
mstore(element, elementLength)
// Copy the `subject` one word at a time, backwards.
for { let o := and(add(elementLength, 0x1f), w) } 1 {} {
mstore(add(element, o), mload(add(add(subject, prevIndex), o)))
o := add(o, w) // `sub(o, 0x20)`.
if iszero(o) { break }
}
// Zeroize the slot after the string.
mstore(add(add(element, 0x20), elementLength), 0)
// Allocate memory for the length and the bytes,
// rounded up to a multiple of 32.
mstore(0x40, add(element, and(add(elementLength, 0x3f), w)))
// Store the `element` into the array.
mstore(indexPtr, element)
}
prevIndex := add(index, mload(delimiter))
indexPtr := add(indexPtr, 0x20)
if iszero(lt(indexPtr, indicesEnd)) { break }
}
result := indices
if iszero(mload(delimiter)) {
result := add(indices, 0x20)
mstore(result, sub(mload(indices), 2))
}
}
}
/// @dev Returns a concatenated string of `a` and `b`.
/// Cheaper than `string.concat()` and does not de-align the free memory pointer.
function concat(string memory a, string memory b)
internal
pure
returns (string memory result)
{
/// @solidity memory-safe-assembly
assembly {
let w := not(0x1f)
result := mload(0x40)
let aLength := mload(a)
// Copy `a` one word at a time, backwards.
for { let o := and(add(aLength, 0x20), w) } 1 {} {
mstore(add(result, o), mload(add(a, o)))
o := add(o, w) // `sub(o, 0x20)`.
if iszero(o) { break }
}
let bLength := mload(b)
let output := add(result, aLength)
// Copy `b` one word at a time, backwards.
for { let o := and(add(bLength, 0x20), w) } 1 {} {
mstore(add(output, o), mload(add(b, o)))
o := add(o, w) // `sub(o, 0x20)`.
if iszero(o) { break }
}
let totalLength := add(aLength, bLength)
let last := add(add(result, 0x20), totalLength)
// Zeroize the slot after the string.
mstore(last, 0)
// Stores the length.
mstore(result, totalLength)
// Allocate memory for the length and the bytes,
// rounded up to a multiple of 32.
mstore(0x40, and(add(last, 0x1f), w))
}
}
/// @dev Returns a copy of the string in either lowercase or UPPERCASE.
/// WARNING! This function is only compatible with 7-bit ASCII strings.
function toCase(string memory subject, bool toUpper)
internal
pure
returns (string memory result)
{
/// @solidity memory-safe-assembly
assembly {
let length := mload(subject)
if length {
result := add(mload(0x40), 0x20)
subject := add(subject, 1)
let flags := shl(add(70, shl(5, toUpper)), 0x3ffffff)
let w := not(0)
for { let o := length } 1 {} {
o := add(o, w)
let b := and(0xff, mload(add(subject, o)))
mstore8(add(result, o), xor(b, and(shr(b, flags), 0x20)))
if iszero(o) { break }
}
result := mload(0x40)
mstore(result, length) // Store the length.
let last := add(add(result, 0x20), length)
mstore(last, 0) // Zeroize the slot after the string.
mstore(0x40, add(last, 0x20)) // Allocate the memory.
}
}
}
/// @dev Returns a lowercased copy of the string.
/// WARNING! This function is only compatible with 7-bit ASCII strings.
function lower(string memory subject) internal pure returns (string memory result) {
result = toCase(subject, false);
}
/// @dev Returns an UPPERCASED copy of the string.
/// WARNING! This function is only compatible with 7-bit ASCII strings.
function upper(string memory subject) internal pure returns (string memory result) {
result = toCase(subject, true);
}
/// @dev Escapes the string to be used within HTML tags.
function escapeHTML(string memory s) internal pure returns (string memory result) {
/// @solidity memory-safe-assembly
assembly {
let end := add(s, mload(s))
result := add(mload(0x40), 0x20)
// Store the bytes of the packed offsets and strides into the scratch space.
// `packed = (stride << 5) | offset`. Max offset is 20. Max stride is 6.
mstore(0x1f, 0x900094)
mstore(0x08, 0xc0000000a6ab)
// Store ""&'<>" into the scratch space.
mstore(0x00, shl(64, 0x2671756f743b26616d703b262333393b266c743b2667743b))
for {} iszero(eq(s, end)) {} {
s := add(s, 1)
let c := and(mload(s), 0xff)
// Not in `["\"","'","&","<",">"]`.
if iszero(and(shl(c, 1), 0x500000c400000000)) {
mstore8(result, c)
result := add(result, 1)
continue
}
let t := shr(248, mload(c))
mstore(result, mload(and(t, 0x1f)))
result := add(result, shr(5, t))
}
let last := result
mstore(last, 0) // Zeroize the slot after the string.
result := mload(0x40)
mstore(result, sub(last, add(result, 0x20))) // Store the length.
mstore(0x40, add(last, 0x20)) // Allocate the memory.
}
}
/// @dev Escapes the string to be used within double-quotes in a JSON.
/// If `addDoubleQuotes` is true, the result will be enclosed in double-quotes.
function escapeJSON(string memory s, bool addDoubleQuotes)
internal
pure
returns (string memory result)
{
/// @solidity memory-safe-assembly
assembly {
let end := add(s, mload(s))
result := add(mload(0x40), 0x20)
if addDoubleQuotes {
mstore8(result, 34)
result := add(1, result)
}
// Store "\\u0000" in scratch space.
// Store "0123456789abcdef" in scratch space.
// Also, store `{0x08:"b", 0x09:"t", 0x0a:"n", 0x0c:"f", 0x0d:"r"}`.
// into the scratch space.
mstore(0x15, 0x5c75303030303031323334353637383961626364656662746e006672)
// Bitmask for detecting `["\"","\\"]`.
let e := or(shl(0x22, 1), shl(0x5c, 1))
for {} iszero(eq(s, end)) {} {
s := add(s, 1)
let c := and(mload(s), 0xff)
if iszero(lt(c, 0x20)) {
if iszero(and(shl(c, 1), e)) {
// Not in `["\"","\\"]`.
mstore8(result, c)
result := add(result, 1)
continue
}
mstore8(result, 0x5c) // "\\".
mstore8(add(result, 1), c)
result := add(result, 2)
continue
}
if iszero(and(shl(c, 1), 0x3700)) {
// Not in `["\b","\t","\n","\f","\d"]`.
mstore8(0x1d, mload(shr(4, c))) // Hex value.
mstore8(0x1e, mload(and(c, 15))) // Hex value.
mstore(result, mload(0x19)) // "\\u00XX".
result := add(result, 6)
continue
}
mstore8(result, 0x5c) // "\\".
mstore8(add(result, 1), mload(add(c, 8)))
result := add(result, 2)
}
if addDoubleQuotes {
mstore8(result, 34)
result := add(1, result)
}
let last := result
mstore(last, 0) // Zeroize the slot after the string.
result := mload(0x40)
mstore(result, sub(last, add(result, 0x20))) // Store the length.
mstore(0x40, add(last, 0x20)) // Allocate the memory.
}
}
/// @dev Escapes the string to be used within double-quotes in a JSON.
function escapeJSON(string memory s) internal pure returns (string memory result) {
result = escapeJSON(s, false);
}
/// @dev Returns whether `a` equals `b`.
function eq(string memory a, string memory b) internal pure returns (bool result) {
/// @solidity memory-safe-assembly
assembly {
result := eq(keccak256(add(a, 0x20), mload(a)), keccak256(add(b, 0x20), mload(b)))
}
}
/// @dev Returns whether `a` equals `b`. For short strings up to 32 bytes.
function eqs(string memory a, bytes32 b) internal pure returns (bool result) {
/// @solidity memory-safe-assembly
assembly {
// These should be evaluated on compile time, as far as possible.
let x := and(b, add(not(b), 1))
let r := or(shl(8, iszero(b)), shl(7, iszero(iszero(shr(128, x)))))
r := or(r, shl(6, iszero(iszero(shr(64, shr(r, x))))))
r := or(r, shl(5, lt(0xffffffff, shr(r, x))))
r := or(r, shl(4, lt(0xffff, shr(r, x))))
r := or(r, shl(3, lt(0xff, shr(r, x))))
result := gt(eq(mload(a), sub(32, shr(3, r))), shr(r, xor(b, mload(add(a, 0x20)))))
}
}
/// @dev Packs a single string with its length into a single word.
/// Returns `bytes32(0)` if the length is zero or greater than 31.
function packOne(string memory a) internal pure returns (bytes32 result) {
/// @solidity memory-safe-assembly
assembly {
// We don't need to zero right pad the string,
// since this is our own custom non-standard packing scheme.
result :=
mul(
// Load the length and the bytes.
mload(add(a, 0x1f)),
// `length != 0 && length < 32`. Abuses underflow.
// Assumes that the length is valid and within the block gas limit.
lt(sub(mload(a), 1), 0x1f)
)
}
}
/// @dev Unpacks a string packed using {packOne}.
/// Returns the empty string if `packed` is `bytes32(0)`.
/// If `packed` is not an output of {packOne}, the output behaviour is undefined.
function unpackOne(bytes32 packed) internal pure returns (string memory result) {
/// @solidity memory-safe-assembly
assembly {
// Grab the free memory pointer.
result := mload(0x40)
// Allocate 2 words (1 for the length, 1 for the bytes).
mstore(0x40, add(result, 0x40))
// Zeroize the length slot.
mstore(result, 0)
// Store the length and bytes.
mstore(add(result, 0x1f), packed)
// Right pad with zeroes.
mstore(add(add(result, 0x20), mload(result)), 0)
}
}
/// @dev Packs two strings with their lengths into a single word.
/// Returns `bytes32(0)` if combined length is zero or greater than 30.
function packTwo(string memory a, string memory b) internal pure returns (bytes32 result) {
/// @solidity memory-safe-assembly
assembly {
let aLength := mload(a)
// We don't need to zero right pad the strings,
// since this is our own custom non-standard packing scheme.
result :=
mul(
// Load the length and the bytes of `a` and `b`.
or(
shl(shl(3, sub(0x1f, aLength)), mload(add(a, aLength))),
mload(sub(add(b, 0x1e), aLength))
),
// `totalLength != 0 && totalLength < 31`. Abuses underflow.
// Assumes that the lengths are valid and within the block gas limit.
lt(sub(add(aLength, mload(b)), 1), 0x1e)
)
}
}
/// @dev Unpacks strings packed using {packTwo}.
/// Returns the empty strings if `packed` is `bytes32(0)`.
/// If `packed` is not an output of {packTwo}, the output behaviour is undefined.
function unpackTwo(bytes32 packed)
internal
pure
returns (string memory resultA, string memory resultB)
{
/// @solidity memory-safe-assembly
assembly {
// Grab the free memory pointer.
resultA := mload(0x40)
resultB := add(resultA, 0x40)
// Allocate 2 words for each string (1 for the length, 1 for the byte). Total 4 words.
mstore(0x40, add(resultB, 0x40))
// Zeroize the length slots.
mstore(resultA, 0)
mstore(resultB, 0)
// Store the lengths and bytes.
mstore(add(resultA, 0x1f), packed)
mstore(add(resultB, 0x1f), mload(add(add(resultA, 0x20), mload(resultA))))
// Right pad with zeroes.
mstore(add(add(resultA, 0x20), mload(resultA)), 0)
mstore(add(add(resultB, 0x20), mload(resultB)), 0)
}
}
/// @dev Directly returns `a` without copying.
function directReturn(string memory a) internal pure {
assembly {
// Assumes that the string does not start from the scratch space.
let retStart := sub(a, 0x20)
let retSize := add(mload(a), 0x40)
// Right pad with zeroes. Just in case the string is produced
// by a method that doesn't zero right pad.
mstore(add(retStart, retSize), 0)
// Store the return offset.
mstore(retStart, 0x20)
// End the transaction, returning the string.
return(retStart, retSize)
}
}
}