A Kotlin Multiplatform library for arbitrary precision mathematics, providing unified APIs for high-precision arithmetic operations across Android, iOS, and Web platforms.

• Arbitrary Precision Arithmetic: Handle numbers with unlimited precision using KBigDecimal and KBigInteger.
• Mathematical Mathematical: gcd, lcm, factorial, sqrt, pow.
• Bitwise Operations: and, or, xor, not, andNot (with full 2's complement behavior).
• Pure Kotlin Implementation: No JNI or native dependencies required, ensuring maximum compatibility.
• Multiplatform Support: Single codebase works seamlessly on Android, iOS, JVM, JS, and Native.
• Type-Safe API: Strongly typed interfaces mimicking Java's BigDecimal/BigInteger.
• Natural Syntax: Operator overloading (+, -, *, /) for intuitive mathematical expressions.

Add to your build.gradle.kts:

dependencies {
    implementation("io.github.gatrongdev:kbignum:VERSION")
}

Add to your build.gradle:

dependencies {
    implementation 'io.github.gatrongdev:kbignum:VERSION'
}

KBignum offers competitive performance by utilizing efficient algorithms (Knuth's Algorithm D for division, optimized magnitude arithmetic). Below is a comparison against Java's native implementations on JVM:

Note: Benchmarks run on macOS/JVM. ✓ indicates KBignum is faster or equal to Java. KBignum prioritizes portability across KMP targets (Android, iOS, JS, Native).

import io.github.gatrongdev.kbignum.math.*

// Creating big numbers
val bigDecimal1 = "123.456789".toKBigDecimal()
val bigDecimal2 = KBigDecimal.fromString("987.654321")
val bigInteger = "12345678901234567890".toKBigInteger()

// Basic arithmetic
val sum = bigDecimal1 + bigDecimal2
val difference = bigDecimal1 - bigDecimal2
val product = bigDecimal1 * bigDecimal2

// Division (Operator '/' defaults to scale 10, HALF_UP)
val quotient = bigDecimal1 / bigDecimal2

// Precise Division
val preciseQuotient = bigDecimal1.divide(bigDecimal2, scale = 20, rounding = KBRoundingMode.HalfUp)

// Advanced operations
val sqrt = KBigMath.sqrt(bigDecimal1, 10)
val factorial = KBigMath.factorial(bigInteger)
val isPrime = KBigMath.isPrime(bigInteger)

// Convert from various types
val fromString = "999.999".toKBigDecimal()
val fromInt = 42.toKBigInteger()
val fromLong = 1234567890L.toKBigDecimal()

// Utility functions
val isZero = bigDecimal1.isZero()
val isPositive = bigDecimal1.isPositive()
val absolute = bigDecimal1.abs()
val sign = bigDecimal1.signum()

// Mathematical operations
val gcd = KBigMath.gcd(bigInteger1, bigInteger2)
val lcm = KBigMath.lcm(bigInteger1, bigInteger2)
val power = bigDecimal1.pow(5)

• Minimum API Level: 21
• Implementation: Pure Kotlin (Single Codebase). No JNI involved.
• Output: AAR library files

• SDK levels are centralized in the root gradle.properties (android.compileSdk, android.minSdk, android.targetSdk).
• Override them per build by supplying Gradle properties, e.g.:

  ./gradlew :shared:assembleRelease -Pandroid.compileSdk=34 -Pandroid.targetSdk=34

• Module builds automatically pick up the configured values; no manual edits inside shared/build.gradle.kts are required.

• Minimum Version: 13.0
• Implementation: Pure Kotlin (Single Codebase). No NSDecimalNumber bridging overhead.
• Output: XCFramework with arm64 and x64 support

• Kotlin: 1.9.10+
• Gradle: 8.11.1+
• Android: API level 21+
• iOS: 13.0+

This project is licensed under the Apache License, Version 2.0 - see the LICENSE file for details.

Gatrong Dev - GitHub