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Add toUint, toInt and hexToUint to Strings (#5166)

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Co-authored-by: cairo <cairoeth@protonmail.com>
Co-authored-by: Ernesto García <ernestognw@gmail.com>
This commit is contained in:
Hadrien Croubois
2024-10-14 17:13:33 +02:00
committed by GitHub
parent 72c152dc1c
commit bd588959ad
6 changed files with 503 additions and 68 deletions
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284
contracts/utils/Strings.sol
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@ -4,12 +4,15 @@
pragma solidity ^0.8.20;
import {Math} from "./math/Math.sol";
import {SafeCast} from "./math/SafeCast.sol";
import {SignedMath} from "./math/SignedMath.sol";
/**
* @dev String operations.
*/
library Strings {
using SafeCast for *;
bytes16 private constant HEX_DIGITS = "0123456789abcdef";
uint8 private constant ADDRESS_LENGTH = 20;
@ -18,6 +21,16 @@ library Strings {
*/
error StringsInsufficientHexLength(uint256 value, uint256 length);
/**
* @dev The string being parsed contains characters that are not in scope of the given base.
*/
error StringsInvalidChar();
/**
* @dev The string being parsed is not a properly formatted address.
*/
error StringsInvalidAddressFormat();
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
@ -113,4 +126,275 @@ library Strings {
function equal(string memory a, string memory b) internal pure returns (bool) {
return bytes(a).length == bytes(b).length && keccak256(bytes(a)) == keccak256(bytes(b));
}
/**
* @dev Parse a decimal string and returns the value as a `uint256`.
*
* Requirements:
* - The string must be formatted as `[0-9]*`
* - The result must fit into an `uint256` type
*/
function parseUint(string memory input) internal pure returns (uint256) {
return parseUint(input, 0, bytes(input).length);
}
/**
* @dev Variant of {parseUint} that parses a substring of `input` located between position `begin` (included) and
* `end` (excluded).
*
* Requirements:
* - The substring must be formatted as `[0-9]*`
* - The result must fit into an `uint256` type
*/
function parseUint(string memory input, uint256 begin, uint256 end) internal pure returns (uint256) {
(bool success, uint256 value) = tryParseUint(input, begin, end);
if (!success) revert StringsInvalidChar();
return value;
}
/**
* @dev Variant of {parseUint-string} that returns false if the parsing fails because of an invalid character.
*
* NOTE: This function will revert if the result does not fit in a `uint256`.
*/
function tryParseUint(string memory input) internal pure returns (bool success, uint256 value) {
return tryParseUint(input, 0, bytes(input).length);
}
/**
* @dev Variant of {parseUint-string-uint256-uint256} that returns false if the parsing fails because of an invalid
* character.
*
* NOTE: This function will revert if the result does not fit in a `uint256`.
*/
function tryParseUint(
string memory input,
uint256 begin,
uint256 end
) internal pure returns (bool success, uint256 value) {
bytes memory buffer = bytes(input);
uint256 result = 0;
for (uint256 i = begin; i < end; ++i) {
uint8 chr = _tryParseChr(bytes1(_unsafeReadBytesOffset(buffer, i)));
if (chr > 9) return (false, 0);
result *= 10;
result += chr;
}
return (true, result);
}
/**
* @dev Parse a decimal string and returns the value as a `int256`.
*
* Requirements:
* - The string must be formatted as `[-+]?[0-9]*`
* - The result must fit in an `int256` type.
*/
function parseInt(string memory input) internal pure returns (int256) {
return parseInt(input, 0, bytes(input).length);
}
/**
* @dev Variant of {parseInt-string} that parses a substring of `input` located between position `begin` (included) and
* `end` (excluded).
*
* Requirements:
* - The substring must be formatted as `[-+]?[0-9]*`
* - The result must fit in an `int256` type.
*/
function parseInt(string memory input, uint256 begin, uint256 end) internal pure returns (int256) {
(bool success, int256 value) = tryParseInt(input, begin, end);
if (!success) revert StringsInvalidChar();
return value;
}
/**
* @dev Variant of {parseInt-string} that returns false if the parsing fails because of an invalid character or if
* the result does not fit in a `int256`.
*
* NOTE: This function will revert if the absolute value of the result does not fit in a `uint256`.
*/
function tryParseInt(string memory input) internal pure returns (bool success, int256 value) {
return tryParseInt(input, 0, bytes(input).length);
}
uint256 private constant ABS_MIN_INT256 = 2 ** 255;
/**
* @dev Variant of {parseInt-string-uint256-uint256} that returns false if the parsing fails because of an invalid
* character or if the result does not fit in a `int256`.
*
* NOTE: This function will revert if the absolute value of the result does not fit in a `uint256`.
*/
function tryParseInt(
string memory input,
uint256 begin,
uint256 end
) internal pure returns (bool success, int256 value) {
bytes memory buffer = bytes(input);
// Check presence of a negative sign.
bytes1 sign = bytes1(_unsafeReadBytesOffset(buffer, begin));
bool positiveSign = sign == bytes1("+");
bool negativeSign = sign == bytes1("-");
uint256 offset = (positiveSign || negativeSign).toUint();
(bool absSuccess, uint256 absValue) = tryParseUint(input, begin + offset, end);
if (absSuccess && absValue < ABS_MIN_INT256) {
return (true, negativeSign ? -int256(absValue) : int256(absValue));
} else if (absSuccess && negativeSign && absValue == ABS_MIN_INT256) {
return (true, type(int256).min);
} else return (false, 0);
}
/**
* @dev Parse a hexadecimal string (with or without "0x" prefix), and returns the value as a `uint256`.
*
* Requirements:
* - The string must be formatted as `(0x)?[0-9a-fA-F]*`
* - The result must fit in an `uint256` type.
*/
function parseHexUint(string memory input) internal pure returns (uint256) {
return parseHexUint(input, 0, bytes(input).length);
}
/**
* @dev Variant of {parseHexUint} that parses a substring of `input` located between position `begin` (included) and
* `end` (excluded).
*
* Requirements:
* - The substring must be formatted as `(0x)?[0-9a-fA-F]*`
* - The result must fit in an `uint256` type.
*/
function parseHexUint(string memory input, uint256 begin, uint256 end) internal pure returns (uint256) {
(bool success, uint256 value) = tryParseHexUint(input, begin, end);
if (!success) revert StringsInvalidChar();
return value;
}
/**
* @dev Variant of {parseHexUint-string} that returns false if the parsing fails because of an invalid character.
*
* NOTE: This function will revert if the result does not fit in a `uint256`.
*/
function tryParseHexUint(string memory input) internal pure returns (bool success, uint256 value) {
return tryParseHexUint(input, 0, bytes(input).length);
}
/**
* @dev Variant of {parseHexUint-string-uint256-uint256} that returns false if the parsing fails because of an
* invalid character.
*
* NOTE: This function will revert if the result does not fit in a `uint256`.
*/
function tryParseHexUint(
string memory input,
uint256 begin,
uint256 end
) internal pure returns (bool success, uint256 value) {
bytes memory buffer = bytes(input);
// skip 0x prefix if present
bool hasPrefix = bytes2(_unsafeReadBytesOffset(buffer, begin)) == bytes2("0x");
uint256 offset = hasPrefix.toUint() * 2;
uint256 result = 0;
for (uint256 i = begin + offset; i < end; ++i) {
uint8 chr = _tryParseChr(bytes1(_unsafeReadBytesOffset(buffer, i)));
if (chr > 15) return (false, 0);
result *= 16;
unchecked {
// Multiplying by 16 is equivalent to a shift of 4 bits (with additional overflow check).
// This guaratees that adding a value < 16 will not cause an overflow, hence the unchecked.
result += chr;
}
}
return (true, result);
}
/**
* @dev Parse a hexadecimal string (with or without "0x" prefix), and returns the value as an `address`.
*
* Requirements:
* - The string must be formatted as `(0x)?[0-9a-fA-F]{40}`
*/
function parseAddress(string memory input) internal pure returns (address) {
return parseAddress(input, 0, bytes(input).length);
}
/**
* @dev Variant of {parseAddress} that parses a substring of `input` located between position `begin` (included) and
* `end` (excluded).
*
* Requirements:
* - The substring must be formatted as `(0x)?[0-9a-fA-F]{40}`
*/
function parseAddress(string memory input, uint256 begin, uint256 end) internal pure returns (address) {
(bool success, address value) = tryParseAddress(input, begin, end);
if (!success) revert StringsInvalidAddressFormat();
return value;
}
/**
* @dev Variant of {parseAddress-string} that returns false if the parsing fails because the input is not a properly
* formatted address. See {parseAddress} requirements.
*/
function tryParseAddress(string memory input) internal pure returns (bool success, address value) {
return tryParseAddress(input, 0, bytes(input).length);
}
/**
* @dev Variant of {parseAddress-string-uint256-uint256} that returns false if the parsing fails because input is not a properly
* formatted address. See {parseAddress} requirements.
*/
function tryParseAddress(
string memory input,
uint256 begin,
uint256 end
) internal pure returns (bool success, address value) {
// check that input is the correct length
bool hasPrefix = bytes2(_unsafeReadBytesOffset(bytes(input), begin)) == bytes2("0x");
uint256 expectedLength = 40 + hasPrefix.toUint() * 2;
if (end - begin == expectedLength) {
// length guarantees that this does not overflow, and value is at most type(uint160).max
(bool s, uint256 v) = tryParseHexUint(input, begin, end);
return (s, address(uint160(v)));
} else {
return (false, address(0));
}
}
function _tryParseChr(bytes1 chr) private pure returns (uint8) {
uint8 value = uint8(chr);
// Try to parse `chr`:
// - Case 1: [0-9]
// - Case 2: [a-f]
// - Case 3: [A-F]
// - otherwise not supported
unchecked {
if (value > 47 && value < 58) value -= 48;
else if (value > 96 && value < 103) value -= 87;
else if (value > 64 && value < 71) value -= 55;
else return type(uint8).max;
}
return value;
}
/**
* @dev Reads a bytes32 from a bytes array without bounds checking.
*
* NOTE: making this function internal would mean it could be used with memory unsafe offset, and marking the
* assembly block as such would prevent some optimizations.
*/
function _unsafeReadBytesOffset(bytes memory buffer, uint256 offset) private pure returns (bytes32 value) {
// This is not memory safe in the general case, but all calls to this private function are within bounds.
assembly ("memory-safe") {
value := mload(add(buffer, add(0x20, offset)))
}
}
}