https://github.com/dankogai/swift-bignum
Arbitrary-precision arithmetic for Swift, in Swift
https://github.com/dankogai/swift-bignum
arbitrary-precision floatingpoint math rational-numbers swift
Last synced: over 1 year ago
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Arbitrary-precision arithmetic for Swift, in Swift
- Host: GitHub
- URL: https://github.com/dankogai/swift-bignum
- Owner: dankogai
- License: mit
- Created: 2016-02-02T02:40:58.000Z (over 10 years ago)
- Default Branch: main
- Last Pushed: 2023-11-16T11:56:39.000Z (over 2 years ago)
- Last Synced: 2025-03-18T11:22:50.523Z (over 1 year ago)
- Topics: arbitrary-precision, floatingpoint, math, rational-numbers, swift
- Language: Swift
- Size: 1.73 MB
- Stars: 28
- Watchers: 5
- Forks: 8
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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# swift-bignum
Arbitrary-precision arithmetic for Swift, in Swift
## Synopsis
````swift
import BigNum
BigRat.sqrt(2, precision:128) // 240615969168004511545033772477625056927/170141183460469231731687303715884105728
BigFloat.exp(1, precision:128) // 2.718281828459045235360287471352662497759
````
## Description
This module offers two flavors of Arbitrary-precision types that conforms to [FloatingPoint].
* `BigRat` - Arbitrary-precision rational number.
* `BigFloat` - Arbitrary-precision floating point.
[FloatingPoint]: https://developer.apple.com/documentation/swift/floatingpoint
In addition to all arithmetic operations that [FloatingPoint] supports. Most of the functions in `` are offered as static functions. As you see in the synopsis above, all arithmetic functions and operators that are lossy can take `precision:Int` as an optional argument. When omitted the value of `BigRat.precision` or `BigFloat.precision` is used (default:64).
```swift
BigFloat.sqrt(2) // 1.41421356237309504876
BigFloat.precision = 128
BigFloat.sqrt(2) // 1.414213562373095048801688724209698078569
```
`BigInt`, an arbitrary-precision interger type is internally used and re-exported so you don't have to `import BigInt` just for that. `BigInt` is also extended with `.over()` method so instead of constructing `BigRat` directly, you can:
```swift
BigInt(3260954456333195553).over(BigInt(2305843009213693952)) // == BigRat.sqrt(2)
```
## Usage
### Build
```sh
$ git clone https://github.com/dankogai/swift-bignum.git
$ cd swift-bignum # the following assumes your $PWD is here
$ swift build
```
### REPL
Simply
```sh
$ scripts/run-repl.sh
```
or
```sh
$ swift run --repl
```
and in your repl,
```sh
[0/0] Build complete!
Launching Swift REPL with arguments: -I/Users/dankogai/github/swift-bignum/.build/x86_64-apple-macosx/release -L/Users/dankogai/github/swift-bignum/.build/x86_64-apple-macosx/release -lBigNum__REPL -I/Users/dankogai/github/swift-bignum/.build/checkouts/swift-numerics/Sources/_NumericsShims/include
Welcome to Swift version 5.5.2-dev.
Type :help for assistance.
1> import BigNum
2> var bf = BigFloat.sqrt(2, precision:128)
bf: BigNum.BigFloat = {
scale = -127
mantissa = {
magnitude = {
kind = array
storage = 2 values {
[0] = 6448461645324402335
[1] = 13043817825332782212
}
}
sign = plus
}
}
3> print(bf)
1.414213562373095048801688724209698078569
````
### From your Xcode Projects.
Simply add the package from **Package Dependencies** tab of the Project.
Enter `https://github.com/dankogai/swift-bignum` in the search field and click `[Add Package]`
Now you are able to `import BigNum`.
Now all you have to do is build and enjoy!
If you enconter errors like `Missing required module '_NumericShims'`, try cleaning up your `~/Library/Developer/Xcode/DerivedData`.
### From Your SwiftPM-Managed Projects
Add the following to the `dependencies` section:
```swift
.package(
url: "https://github.com/dankogai/swift-bignum.git", .branch("main")
)
```
and the following to the `.target` argument:
```swift
.target(
name: "YourSwiftyPackage",
dependencies: ["BigNum"])
```
Now all you have to do is:
```swift
import BigNum
```
in your code. Enjoy!
# Prerequisite
Swift 5 or better, OS X or Linux to build.
* Depends on [attaswift/BigInt] for internal representation of
`BigFloat` and `BigRat`.
* Depends on [apple/swift-numerics] since
version 5.1 for the `ElementaryFunctions` protocol.
* Prior versions depended on [dankogai/swift-floatingpoint] for the
`FloatingPointMath` protocols but it is replaced by the
`ElementaryFunctions`.
[attaswift/BigInt]: https://github.com/attaswift/BigInt
[apple/swift-numerics]: https://github.com/apple/swift-numerics
[dankogai/swift-floatingpoint]: https://github.com/danogai/swift-floatingpoint