@pacote/u64 NPM

@pacote/u64

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Unsigned 64-bit integers.

This package exists because while modern JavaScript environments support very large integers via the BigInt type, it is not available in older browsers and tooling doesn't always transpile BigInt operations into a backwards-compatible format.

If you target ECMAScript 2020 or later, you will probably not need this.

The U64 type provided by this package is represented as a tuple of four 16-bit integers. For example, the number 1 is [1, 0, 0, 0]. It is not an object class with built-in methods. Instead of methods, the package provides functions to support commonly-used operations.

Installation

yarn add @pacote/u64

Example

import { add, from, toString } from '@pacote/u64'

const result = add(from('1609587929392839161'), from('9650029242287828579'))

toString(result) // -> '11259617171680667740'

Comparison functions

`equals(a: U64, b: U64): U64`

Compares two U64 values and returns true if they are numerically equivalent, otherwise returns false.

`lessThan(a: U64, b: U64): U64`

Compares two U64 values and returns true if a is smaller than b, otherwise returns false.

`greaterThan(a: U64, b: U64): U64`

Compares two U64 values and returns true if a is greater than b, otherwise returns false.

Binary bitwise functions

`and(a: U64, b: U64): U64`

The bitwise AND function returns a 1 in each bit position for which the corresponding bits of both operands are 1s. Equivalent to the numeric & operator.

`or(a: U64, b: U64): U64`

The bitwise OR function returns a 1 in each bit position for which the corresponding bits of either operand are 1s. Equivalent to the numeric | operator.

`xor(a: U64, b: U64): U64`

The bitwise XOR function returns a 1 in each bit position for which the corresponding bits of either but not both operands are 1s. Equivalent to the numeric ^ operator.

Bitwise shift functions

`rotateLeft(value: U64, bits: number): U64`

The left rotate function circularly shifts the value the specified number of bits to the left. Bits shifted off to the left appear on the right.

`rotateRight(value: U64, bits: number): U64`

The right rotate function circularly shifts the value the specified number of bits to the right. Bits shifted off to the right appear on the left.

`shiftLeft(value: U64, bits: number): U64`

The left shift function shifts the value the specified number of bits to the left. Excess bits shifted off to the left are discarded. Zero bits are shifted in from the right. Equivalent to the numeric << operator.

`shiftRight(value: U64, bits: number): U64`

The right shift function shifts the value the specified number of bits to the right. Excess bits shifted off to the right are discarded. Zero bits are shifted in from the left. The sign bit becomes 0, so the result is always non-negative. Equivalent to the numeric >>> operator.

Conversion functions

`toNumber(value: U64): number`

Coerces a U64 value to number.

Because JavaScript numbers are not 64-bit, precision may be lost when converting. Only numbers with up to 32-bit precision (2^32, or 4294967296) can be safely converted into number.