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Diffstat (limited to 'vendor/brick/math/src/BigInteger.php')
| -rw-r--r-- | vendor/brick/math/src/BigInteger.php | 1134 |
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diff --git a/vendor/brick/math/src/BigInteger.php b/vendor/brick/math/src/BigInteger.php new file mode 100644 index 000000000..cee3ce82b --- /dev/null +++ b/vendor/brick/math/src/BigInteger.php @@ -0,0 +1,1134 @@ +<?php + +declare(strict_types=1); + +namespace Brick\Math; + +use Brick\Math\Exception\DivisionByZeroException; +use Brick\Math\Exception\IntegerOverflowException; +use Brick\Math\Exception\MathException; +use Brick\Math\Exception\NegativeNumberException; +use Brick\Math\Exception\NumberFormatException; +use Brick\Math\Internal\Calculator; + +/** + * An arbitrary-size integer. + * + * All methods accepting a number as a parameter accept either a BigInteger instance, + * an integer, or a string representing an arbitrary size integer. + * + * @psalm-immutable + */ +final class BigInteger extends BigNumber +{ + /** + * The value, as a string of digits with optional leading minus sign. + * + * No leading zeros must be present. + * No leading minus sign must be present if the number is zero. + * + * @var string + */ + private $value; + + /** + * Protected constructor. Use a factory method to obtain an instance. + * + * @param string $value A string of digits, with optional leading minus sign. + */ + protected function __construct(string $value) + { + $this->value = $value; + } + + /** + * Creates a BigInteger of the given value. + * + * @param BigNumber|int|float|string $value + * + * @return BigInteger + * + * @throws MathException If the value cannot be converted to a BigInteger. + * + * @psalm-pure + */ + public static function of($value) : BigNumber + { + return parent::of($value)->toBigInteger(); + } + + /** + * Creates a number from a string in a given base. + * + * The string can optionally be prefixed with the `+` or `-` sign. + * + * Bases greater than 36 are not supported by this method, as there is no clear consensus on which of the lowercase + * or uppercase characters should come first. Instead, this method accepts any base up to 36, and does not + * differentiate lowercase and uppercase characters, which are considered equal. + * + * For bases greater than 36, and/or custom alphabets, use the fromArbitraryBase() method. + * + * @param string $number The number to convert, in the given base. + * @param int $base The base of the number, between 2 and 36. + * + * @return BigInteger + * + * @throws NumberFormatException If the number is empty, or contains invalid chars for the given base. + * @throws \InvalidArgumentException If the base is out of range. + * + * @psalm-pure + */ + public static function fromBase(string $number, int $base) : BigInteger + { + if ($number === '') { + throw new NumberFormatException('The number cannot be empty.'); + } + + if ($base < 2 || $base > 36) { + throw new \InvalidArgumentException(\sprintf('Base %d is not in range 2 to 36.', $base)); + } + + if ($number[0] === '-') { + $sign = '-'; + $number = \substr($number, 1); + } elseif ($number[0] === '+') { + $sign = ''; + $number = \substr($number, 1); + } else { + $sign = ''; + } + + if ($number === '') { + throw new NumberFormatException('The number cannot be empty.'); + } + + $number = \ltrim($number, '0'); + + if ($number === '') { + // The result will be the same in any base, avoid further calculation. + return BigInteger::zero(); + } + + if ($number === '1') { + // The result will be the same in any base, avoid further calculation. + return new BigInteger($sign . '1'); + } + + $pattern = '/[^' . \substr(Calculator::ALPHABET, 0, $base) . ']/'; + + if (\preg_match($pattern, \strtolower($number), $matches) === 1) { + throw new NumberFormatException(\sprintf('"%s" is not a valid character in base %d.', $matches[0], $base)); + } + + if ($base === 10) { + // The number is usable as is, avoid further calculation. + return new BigInteger($sign . $number); + } + + $result = Calculator::get()->fromBase($number, $base); + + return new BigInteger($sign . $result); + } + + /** + * Parses a string containing an integer in an arbitrary base, using a custom alphabet. + * + * Because this method accepts an alphabet with any character, including dash, it does not handle negative numbers. + * + * @param string $number The number to parse. + * @param string $alphabet The alphabet, for example '01' for base 2, or '01234567' for base 8. + * + * @return BigInteger + * + * @throws NumberFormatException If the given number is empty or contains invalid chars for the given alphabet. + * @throws \InvalidArgumentException If the alphabet does not contain at least 2 chars. + * + * @psalm-pure + */ + public static function fromArbitraryBase(string $number, string $alphabet) : BigInteger + { + if ($number === '') { + throw new NumberFormatException('The number cannot be empty.'); + } + + $base = \strlen($alphabet); + + if ($base < 2) { + throw new \InvalidArgumentException('The alphabet must contain at least 2 chars.'); + } + + $pattern = '/[^' . \preg_quote($alphabet, '/') . ']/'; + + if (\preg_match($pattern, $number, $matches) === 1) { + throw NumberFormatException::charNotInAlphabet($matches[0]); + } + + $number = Calculator::get()->fromArbitraryBase($number, $alphabet, $base); + + return new BigInteger($number); + } + + /** + * Translates a string of bytes containing the binary representation of a BigInteger into a BigInteger. + * + * The input string is assumed to be in big-endian byte-order: the most significant byte is in the zeroth element. + * + * If `$signed` is true, the input is assumed to be in two's-complement representation, and the leading bit is + * interpreted as a sign bit. If `$signed` is false, the input is interpreted as an unsigned number, and the + * resulting BigInteger will always be positive or zero. + * + * This method can be used to retrieve a number exported by `toBytes()`, as long as the `$signed` flags match. + * + * @param string $value The byte string. + * @param bool $signed Whether to interpret as a signed number in two's-complement representation with a leading + * sign bit. + * + * @return BigInteger + * + * @throws NumberFormatException If the string is empty. + */ + public static function fromBytes(string $value, bool $signed = true) : BigInteger + { + if ($value === '') { + throw new NumberFormatException('The byte string must not be empty.'); + } + + $twosComplement = false; + + if ($signed) { + $x = \ord($value[0]); + + if (($twosComplement = ($x >= 0x80))) { + $value = ~$value; + } + } + + $number = self::fromBase(\bin2hex($value), 16); + + if ($twosComplement) { + return $number->plus(1)->negated(); + } + + return $number; + } + + /** + * Generates a pseudo-random number in the range 0 to 2^numBits - 1. + * + * Using the default random bytes generator, this method is suitable for cryptographic use. + * + * @param int $numBits The number of bits. + * @param callable|null $randomBytesGenerator A function that accepts a number of bytes as an integer, and returns a + * string of random bytes of the given length. Defaults to the + * `random_bytes()` function. + * + * @return BigInteger + * + * @throws \InvalidArgumentException If $numBits is negative. + */ + public static function randomBits(int $numBits, ?callable $randomBytesGenerator = null) : BigInteger + { + if ($numBits < 0) { + throw new \InvalidArgumentException('The number of bits cannot be negative.'); + } + + if ($numBits === 0) { + return BigInteger::zero(); + } + + if ($randomBytesGenerator === null) { + $randomBytesGenerator = 'random_bytes'; + } + + $byteLength = \intdiv($numBits - 1, 8) + 1; + + $extraBits = ($byteLength * 8 - $numBits); + $bitmask = \chr(0xFF >> $extraBits); + + $randomBytes = $randomBytesGenerator($byteLength); + $randomBytes[0] = $randomBytes[0] & $bitmask; + + return self::fromBytes($randomBytes, false); + } + + /** + * Generates a pseudo-random number between `$min` and `$max`. + * + * Using the default random bytes generator, this method is suitable for cryptographic use. + * + * @param BigNumber|int|float|string $min The lower bound. Must be convertible to a BigInteger. + * @param BigNumber|int|float|string $max The upper bound. Must be convertible to a BigInteger. + * @param callable|null $randomBytesGenerator A function that accepts a number of bytes as an integer, + * and returns a string of random bytes of the given length. + * Defaults to the `random_bytes()` function. + * + * @return BigInteger + * + * @throws MathException If one of the parameters cannot be converted to a BigInteger, + * or `$min` is greater than `$max`. + */ + public static function randomRange($min, $max, ?callable $randomBytesGenerator = null) : BigInteger + { + $min = BigInteger::of($min); + $max = BigInteger::of($max); + + if ($min->isGreaterThan($max)) { + throw new MathException('$min cannot be greater than $max.'); + } + + if ($min->isEqualTo($max)) { + return $min; + } + + $diff = $max->minus($min); + $bitLength = $diff->getBitLength(); + + // try until the number is in range (50% to 100% chance of success) + do { + $randomNumber = self::randomBits($bitLength, $randomBytesGenerator); + } while ($randomNumber->isGreaterThan($diff)); + + return $randomNumber->plus($min); + } + + /** + * Returns a BigInteger representing zero. + * + * @return BigInteger + * + * @psalm-pure + */ + public static function zero() : BigInteger + { + /** @psalm-suppress ImpureStaticVariable */ + static $zero; + + if ($zero === null) { + $zero = new BigInteger('0'); + } + + return $zero; + } + + /** + * Returns a BigInteger representing one. + * + * @return BigInteger + * + * @psalm-pure + */ + public static function one() : BigInteger + { + /** @psalm-suppress ImpureStaticVariable */ + static $one; + + if ($one === null) { + $one = new BigInteger('1'); + } + + return $one; + } + + /** + * Returns a BigInteger representing ten. + * + * @return BigInteger + * + * @psalm-pure + */ + public static function ten() : BigInteger + { + /** @psalm-suppress ImpureStaticVariable */ + static $ten; + + if ($ten === null) { + $ten = new BigInteger('10'); + } + + return $ten; + } + + /** + * Returns the sum of this number and the given one. + * + * @param BigNumber|int|float|string $that The number to add. Must be convertible to a BigInteger. + * + * @return BigInteger The result. + * + * @throws MathException If the number is not valid, or is not convertible to a BigInteger. + */ + public function plus($that) : BigInteger + { + $that = BigInteger::of($that); + + if ($that->value === '0') { + return $this; + } + + if ($this->value === '0') { + return $that; + } + + $value = Calculator::get()->add($this->value, $that->value); + + return new BigInteger($value); + } + + /** + * Returns the difference of this number and the given one. + * + * @param BigNumber|int|float|string $that The number to subtract. Must be convertible to a BigInteger. + * + * @return BigInteger The result. + * + * @throws MathException If the number is not valid, or is not convertible to a BigInteger. + */ + public function minus($that) : BigInteger + { + $that = BigInteger::of($that); + + if ($that->value === '0') { + return $this; + } + + $value = Calculator::get()->sub($this->value, $that->value); + + return new BigInteger($value); + } + + /** + * Returns the product of this number and the given one. + * + * @param BigNumber|int|float|string $that The multiplier. Must be convertible to a BigInteger. + * + * @return BigInteger The result. + * + * @throws MathException If the multiplier is not a valid number, or is not convertible to a BigInteger. + */ + public function multipliedBy($that) : BigInteger + { + $that = BigInteger::of($that); + + if ($that->value === '1') { + return $this; + } + + if ($this->value === '1') { + return $that; + } + + $value = Calculator::get()->mul($this->value, $that->value); + + return new BigInteger($value); + } + + /** + * Returns the result of the division of this number by the given one. + * + * @param BigNumber|int|float|string $that The divisor. Must be convertible to a BigInteger. + * @param int $roundingMode An optional rounding mode. + * + * @return BigInteger The result. + * + * @throws MathException If the divisor is not a valid number, is not convertible to a BigInteger, is zero, + * or RoundingMode::UNNECESSARY is used and the remainder is not zero. + */ + public function dividedBy($that, int $roundingMode = RoundingMode::UNNECESSARY) : BigInteger + { + $that = BigInteger::of($that); + + if ($that->value === '1') { + return $this; + } + + if ($that->value === '0') { + throw DivisionByZeroException::divisionByZero(); + } + + $result = Calculator::get()->divRound($this->value, $that->value, $roundingMode); + + return new BigInteger($result); + } + + /** + * Returns this number exponentiated to the given value. + * + * @param int $exponent The exponent. + * + * @return BigInteger The result. + * + * @throws \InvalidArgumentException If the exponent is not in the range 0 to 1,000,000. + */ + public function power(int $exponent) : BigInteger + { + if ($exponent === 0) { + return BigInteger::one(); + } + + if ($exponent === 1) { + return $this; + } + + if ($exponent < 0 || $exponent > Calculator::MAX_POWER) { + throw new \InvalidArgumentException(\sprintf( + 'The exponent %d is not in the range 0 to %d.', + $exponent, + Calculator::MAX_POWER + )); + } + + return new BigInteger(Calculator::get()->pow($this->value, $exponent)); + } + + /** + * Returns the quotient of the division of this number by the given one. + * + * @param BigNumber|int|float|string $that The divisor. Must be convertible to a BigInteger. + * + * @return BigInteger + * + * @throws DivisionByZeroException If the divisor is zero. + */ + public function quotient($that) : BigInteger + { + $that = BigInteger::of($that); + + if ($that->value === '1') { + return $this; + } + + if ($that->value === '0') { + throw DivisionByZeroException::divisionByZero(); + } + + $quotient = Calculator::get()->divQ($this->value, $that->value); + + return new BigInteger($quotient); + } + + /** + * Returns the remainder of the division of this number by the given one. + * + * The remainder, when non-zero, has the same sign as the dividend. + * + * @param BigNumber|int|float|string $that The divisor. Must be convertible to a BigInteger. + * + * @return BigInteger + * + * @throws DivisionByZeroException If the divisor is zero. + */ + public function remainder($that) : BigInteger + { + $that = BigInteger::of($that); + + if ($that->value === '1') { + return BigInteger::zero(); + } + + if ($that->value === '0') { + throw DivisionByZeroException::divisionByZero(); + } + + $remainder = Calculator::get()->divR($this->value, $that->value); + + return new BigInteger($remainder); + } + + /** + * Returns the quotient and remainder of the division of this number by the given one. + * + * @param BigNumber|int|float|string $that The divisor. Must be convertible to a BigInteger. + * + * @return BigInteger[] An array containing the quotient and the remainder. + * + * @throws DivisionByZeroException If the divisor is zero. + */ + public function quotientAndRemainder($that) : array + { + $that = BigInteger::of($that); + + if ($that->value === '0') { + throw DivisionByZeroException::divisionByZero(); + } + + [$quotient, $remainder] = Calculator::get()->divQR($this->value, $that->value); + + return [ + new BigInteger($quotient), + new BigInteger($remainder) + ]; + } + + /** + * Returns the modulo of this number and the given one. + * + * The modulo operation yields the same result as the remainder operation when both operands are of the same sign, + * and may differ when signs are different. + * + * The result of the modulo operation, when non-zero, has the same sign as the divisor. + * + * @param BigNumber|int|float|string $that The divisor. Must be convertible to a BigInteger. + * + * @return BigInteger + * + * @throws DivisionByZeroException If the divisor is zero. + */ + public function mod($that) : BigInteger + { + $that = BigInteger::of($that); + + if ($that->value === '0') { + throw DivisionByZeroException::modulusMustNotBeZero(); + } + + $value = Calculator::get()->mod($this->value, $that->value); + + return new BigInteger($value); + } + + /** + * Returns the modular multiplicative inverse of this BigInteger modulo $m. + * + * @param BigInteger $m + * + * @return BigInteger + * + * @throws DivisionByZeroException If $m is zero. + * @throws NegativeNumberException If $m is negative. + * @throws MathException If this BigInteger has no multiplicative inverse mod m (that is, this BigInteger + * is not relatively prime to m). + */ + public function modInverse(BigInteger $m) : BigInteger + { + if ($m->value === '0') { + throw DivisionByZeroException::modulusMustNotBeZero(); + } + + if ($m->isNegative()) { + throw new NegativeNumberException('Modulus must not be negative.'); + } + + if ($m->value === '1') { + return BigInteger::zero(); + } + + $value = Calculator::get()->modInverse($this->value, $m->value); + + if ($value === null) { + throw new MathException('Unable to compute the modInverse for the given modulus.'); + } + + return new BigInteger($value); + } + + /** + * Returns this number raised into power with modulo. + * + * This operation only works on positive numbers. + * + * @param BigNumber|int|float|string $exp The exponent. Must be positive or zero. + * @param BigNumber|int|float|string $mod The modulus. Must be strictly positive. + * + * @return BigInteger + * + * @throws NegativeNumberException If any of the operands is negative. + * @throws DivisionByZeroException If the modulus is zero. + */ + public function modPow($exp, $mod) : BigInteger + { + $exp = BigInteger::of($exp); + $mod = BigInteger::of($mod); + + if ($this->isNegative() || $exp->isNegative() || $mod->isNegative()) { + throw new NegativeNumberException('The operands cannot be negative.'); + } + + if ($mod->isZero()) { + throw DivisionByZeroException::modulusMustNotBeZero(); + } + + $result = Calculator::get()->modPow($this->value, $exp->value, $mod->value); + + return new BigInteger($result); + } + + /** + * Returns the greatest common divisor of this number and the given one. + * + * The GCD is always positive, unless both operands are zero, in which case it is zero. + * + * @param BigNumber|int|float|string $that The operand. Must be convertible to an integer number. + * + * @return BigInteger + */ + public function gcd($that) : BigInteger + { + $that = BigInteger::of($that); + + if ($that->value === '0' && $this->value[0] !== '-') { + return $this; + } + + if ($this->value === '0' && $that->value[0] !== '-') { + return $that; + } + + $value = Calculator::get()->gcd($this->value, $that->value); + + return new BigInteger($value); + } + + /** + * Returns the integer square root number of this number, rounded down. + * + * The result is the largest x such that x² ≤ n. + * + * @return BigInteger + * + * @throws NegativeNumberException If this number is negative. + */ + public function sqrt() : BigInteger + { + if ($this->value[0] === '-') { + throw new NegativeNumberException('Cannot calculate the square root of a negative number.'); + } + + $value = Calculator::get()->sqrt($this->value); + + return new BigInteger($value); + } + + /** + * Returns the absolute value of this number. + * + * @return BigInteger + */ + public function abs() : BigInteger + { + return $this->isNegative() ? $this->negated() : $this; + } + + /** + * Returns the inverse of this number. + * + * @return BigInteger + */ + public function negated() : BigInteger + { + return new BigInteger(Calculator::get()->neg($this->value)); + } + + /** + * Returns the integer bitwise-and combined with another integer. + * + * This method returns a negative BigInteger if and only if both operands are negative. + * + * @param BigNumber|int|float|string $that The operand. Must be convertible to an integer number. + * + * @return BigInteger + */ + public function and($that) : BigInteger + { + $that = BigInteger::of($that); + + return new BigInteger(Calculator::get()->and($this->value, $that->value)); + } + + /** + * Returns the integer bitwise-or combined with another integer. + * + * This method returns a negative BigInteger if and only if either of the operands is negative. + * + * @param BigNumber|int|float|string $that The operand. Must be convertible to an integer number. + * + * @return BigInteger + */ + public function or($that) : BigInteger + { + $that = BigInteger::of($that); + + return new BigInteger(Calculator::get()->or($this->value, $that->value)); + } + + /** + * Returns the integer bitwise-xor combined with another integer. + * + * This method returns a negative BigInteger if and only if exactly one of the operands is negative. + * + * @param BigNumber|int|float|string $that The operand. Must be convertible to an integer number. + * + * @return BigInteger + */ + public function xor($that) : BigInteger + { + $that = BigInteger::of($that); + + return new BigInteger(Calculator::get()->xor($this->value, $that->value)); + } + + /** + * Returns the bitwise-not of this BigInteger. + * + * @return BigInteger + */ + public function not() : BigInteger + { + return $this->negated()->minus(1); + } + + /** + * Returns the integer left shifted by a given number of bits. + * + * @param int $distance The distance to shift. + * + * @return BigInteger + */ + public function shiftedLeft(int $distance) : BigInteger + { + if ($distance === 0) { + return $this; + } + + if ($distance < 0) { + return $this->shiftedRight(- $distance); + } + + return $this->multipliedBy(BigInteger::of(2)->power($distance)); + } + + /** + * Returns the integer right shifted by a given number of bits. + * + * @param int $distance The distance to shift. + * + * @return BigInteger + */ + public function shiftedRight(int $distance) : BigInteger + { + if ($distance === 0) { + return $this; + } + + if ($distance < 0) { + return $this->shiftedLeft(- $distance); + } + + $operand = BigInteger::of(2)->power($distance); + + if ($this->isPositiveOrZero()) { + return $this->quotient($operand); + } + + return $this->dividedBy($operand, RoundingMode::UP); + } + + /** + * Returns the number of bits in the minimal two's-complement representation of this BigInteger, excluding a sign bit. + * + * For positive BigIntegers, this is equivalent to the number of bits in the ordinary binary representation. + * Computes (ceil(log2(this < 0 ? -this : this+1))). + * + * @return int + */ + public function getBitLength() : int + { + if ($this->value === '0') { + return 0; + } + + if ($this->isNegative()) { + return $this->abs()->minus(1)->getBitLength(); + } + + return \strlen($this->toBase(2)); + } + + /** + * Returns the index of the rightmost (lowest-order) one bit in this BigInteger. + * + * Returns -1 if this BigInteger contains no one bits. + * + * @return int + */ + public function getLowestSetBit() : int + { + $n = $this; + $bitLength = $this->getBitLength(); + + for ($i = 0; $i <= $bitLength; $i++) { + if ($n->isOdd()) { + return $i; + } + + $n = $n->shiftedRight(1); + } + + return -1; + } + + /** + * Returns whether this number is even. + * + * @return bool + */ + public function isEven() : bool + { + return \in_array($this->value[-1], ['0', '2', '4', '6', '8'], true); + } + + /** + * Returns whether this number is odd. + * + * @return bool + */ + public function isOdd() : bool + { + return \in_array($this->value[-1], ['1', '3', '5', '7', '9'], true); + } + + /** + * Returns true if and only if the designated bit is set. + * + * Computes ((this & (1<<n)) != 0). + * + * @param int $n The bit to test, 0-based. + * + * @return bool + * + * @throws \InvalidArgumentException If the bit to test is negative. + */ + public function testBit(int $n) : bool + { + if ($n < 0) { + throw new \InvalidArgumentException('The bit to test cannot be negative.'); + } + + return $this->shiftedRight($n)->isOdd(); + } + + /** + * {@inheritdoc} + */ + public function compareTo($that) : int + { + $that = BigNumber::of($that); + + if ($that instanceof BigInteger) { + return Calculator::get()->cmp($this->value, $that->value); + } + + return - $that->compareTo($this); + } + + /** + * {@inheritdoc} + */ + public function getSign() : int + { + return ($this->value === '0') ? 0 : (($this->value[0] === '-') ? -1 : 1); + } + + /** + * {@inheritdoc} + */ + public function toBigInteger() : BigInteger + { + return $this; + } + + /** + * {@inheritdoc} + */ + public function toBigDecimal() : BigDecimal + { + return BigDecimal::create($this->value); + } + + /** + * {@inheritdoc} + */ + public function toBigRational() : BigRational + { + return BigRational::create($this, BigInteger::one(), false); + } + + /** + * {@inheritdoc} + */ + public function toScale(int $scale, int $roundingMode = RoundingMode::UNNECESSARY) : BigDecimal + { + return $this->toBigDecimal()->toScale($scale, $roundingMode); + } + + /** + * {@inheritdoc} + */ + public function toInt() : int + { + $intValue = (int) $this->value; + + if ($this->value !== (string) $intValue) { + throw IntegerOverflowException::toIntOverflow($this); + } + + return $intValue; + } + + /** + * {@inheritdoc} + */ + public function toFloat() : float + { + return (float) $this->value; + } + + /** + * Returns a string representation of this number in the given base. + * + * The output will always be lowercase for bases greater than 10. + * + * @param int $base + * + * @return string + * + * @throws \InvalidArgumentException If the base is out of range. + */ + public function toBase(int $base) : string + { + if ($base === 10) { + return $this->value; + } + + if ($base < 2 || $base > 36) { + throw new \InvalidArgumentException(\sprintf('Base %d is out of range [2, 36]', $base)); + } + + return Calculator::get()->toBase($this->value, $base); + } + + /** + * Returns a string representation of this number in an arbitrary base with a custom alphabet. + * + * Because this method accepts an alphabet with any character, including dash, it does not handle negative numbers; + * a NegativeNumberException will be thrown when attempting to call this method on a negative number. + * + * @param string $alphabet The alphabet, for example '01' for base 2, or '01234567' for base 8. + * + * @return string + * + * @throws NegativeNumberException If this number is negative. + * @throws \InvalidArgumentException If the given alphabet does not contain at least 2 chars. + */ + public function toArbitraryBase(string $alphabet) : string + { + $base = \strlen($alphabet); + + if ($base < 2) { + throw new \InvalidArgumentException('The alphabet must contain at least 2 chars.'); + } + + if ($this->value[0] === '-') { + throw new NegativeNumberException(__FUNCTION__ . '() does not support negative numbers.'); + } + + return Calculator::get()->toArbitraryBase($this->value, $alphabet, $base); + } + + /** + * Returns a string of bytes containing the binary representation of this BigInteger. + * + * The string is in big-endian byte-order: the most significant byte is in the zeroth element. + * + * If `$signed` is true, the output will be in two's-complement representation, and a sign bit will be prepended to + * the output. If `$signed` is false, no sign bit will be prepended, and this method will throw an exception if the + * number is negative. + * + * The string will contain the minimum number of bytes required to represent this BigInteger, including a sign bit + * if `$signed` is true. + * + * This representation is compatible with the `fromBytes()` factory method, as long as the `$signed` flags match. + * + * @param bool $signed Whether to output a signed number in two's-complement representation with a leading sign bit. + * + * @return string + * + * @throws NegativeNumberException If $signed is false, and the number is negative. + */ + public function toBytes(bool $signed = true) : string + { + if (! $signed && $this->isNegative()) { + throw new NegativeNumberException('Cannot convert a negative number to a byte string when $signed is false.'); + } + + $hex = $this->abs()->toBase(16); + + if (\strlen($hex) % 2 !== 0) { + $hex = '0' . $hex; + } + + $baseHexLength = \strlen($hex); + + if ($signed) { + if ($this->isNegative()) { + $hex = \bin2hex(~\hex2bin($hex)); + $hex = self::fromBase($hex, 16)->plus(1)->toBase(16); + + $hexLength = \strlen($hex); + + if ($hexLength < $baseHexLength) { + $hex = \str_repeat('0', $baseHexLength - $hexLength) . $hex; + } + + if ($hex[0] < '8') { + $hex = 'FF' . $hex; + } + } else { + if ($hex[0] >= '8') { + $hex = '00' . $hex; + } + } + } + + return \hex2bin($hex); + } + + /** + * {@inheritdoc} + */ + public function __toString() : string + { + return $this->value; + } + + /** + * This method is required by interface Serializable and SHOULD NOT be accessed directly. + * + * @internal + * + * @return string + */ + public function serialize() : string + { + return $this->value; + } + + /** + * This method is only here to implement interface Serializable and cannot be accessed directly. + * + * @internal + * + * @param string $value + * + * @return void + * + * @throws \LogicException + */ + public function unserialize($value) : void + { + if (isset($this->value)) { + throw new \LogicException('unserialize() is an internal function, it must not be called directly.'); + } + + $this->value = $value; + } +} |