MonsterFloat - Arbitrary Precision Rational Numbers

A TypeScript library for exact arithmetic operations using rational numbers. Unlike floating-point numbers, MonsterFloat represents numbers as fractions with arbitrary-precision integers (using BigInt), ensuring exact calculations without rounding errors.

Features

• Exact arithmetic operations (no floating-point errors)
• Automatic fraction simplification
• Support for arbitrary-precision numbers
• Seamless conversion between number types

Installation

npm install monsterfloat

Usage

Basic Operations

import { MonsterFloat } from 'monsterfloat';

// Create fractions
const half = new MonsterFloat(1n, 2n);        // 1/2
const third = new MonsterFloat(1n, 3n);       // 1/3

// Perform calculations
const sum = half.add(third);                  // 5/6
const product = half.multiply(third);         // 1/6
const quotient = half.divide(third);          // 3/2
const power = half.pow(3);                    // 1/8

// Short-form aliases
const result = half.a(third).m(2).d(4);      // (1/2 + 1/3) * 2 / 4

Comparison Operations

const a = new MonsterFloat(1n, 2n);
const b = new MonsterFloat(3n, 4n);

a.isEqual(0.5);                // true
a.isLessThan(b);              // true
a.isGreaterThanOrEqual(0.25); // true

Conversion Methods

const num = new MonsterFloat(355n, 113n);

num.toNumber();           // 3.1415929203539825 (as JavaScript number)
num.toString();           // "355/113"
num.toNumberString(5n);   // "3.14159" (with specified precision)

Creating from Different Types

MonsterFloat.from(0.5);         // From number
MonsterFloat.from("1.23");      // From string
MonsterFloat.from(42n);         // From BigInt

API Reference

Constructor

• new MonsterFloat(numerator: bigint, denominator: bigint)

Instance Methods

Arithmetic

• add(other: Numeric) or a(other) - Addition
• subtract(other: Numeric) or s(other) - Subtraction
• multiply(other: Numeric) or m(other) - Multiplication
• divide(other: Numeric) or d(other) - Division
• pow(other: Numeric) or p(other) - Exponentiation

Comparison

• isEqual(other: Numeric)
• isLessThan(other: Numeric)
• isLessThanOrEqual(other: Numeric)
• isGreaterThan(other: Numeric)
• isGreaterThanOrEqual(other: Numeric)

Conversion

• toNumber(): number
• toString(): string
• toFractionString(): string
• toNumberString(precision: bigint): string

Static Methods

• from(value: Numeric | string): MonsterFloat

Examples

Exact Decimal Arithmetic

const price = MonsterFloat.from("10.99");
const quantity = MonsterFloat.from(3);
const total = price.multiply(quantity);      // Exactly 32.97

Complex Calculations

const result = MonsterFloat.from(1)
  .divide(7)                                // 1/7
  .multiply(7)                             // 1
  .isEqual(1);                            // true (no floating point errors!)