bn.rs

bn.js and ethers.js BigNumber bindings for Rust & WebAssembly with primitive-types support

Write Rust code that uses bn.js and ethers.js BigNumber numbers

```rust use primitivetypes::{H160, U128}; use wasmbindgen::prelude::*;

use bn_rs::{BigNumber, BN};

[wasm_bindgen]

pub fn sum(a: BigNumber, b: BN) -> Result { // BigNumberError and BNError implement Into<JsValue>, so we can use ? here

let a = i128::try_from(a)?; // std uints are supported
let b: U128 = b.try_into()?; // primitive-types uints supported too

let result = a + b.as_u128() as i128;

Ok(result.into())

}

[wasm_bindgen]

pub fn isdead(targethash: BN, deadhash: BigNumber) -> Result { // primitive-types hashes supported too let hash = H160::tryfrom(targethash)?; let dead = H160::tryfrom(dead_hash)?;

Ok(hash == dead)

} ```

Call it from JavaScript

```javascript import {sum, is_dead} from './pkg' import BN from 'bn.js' import {BigNumber} from "@ethersproject/bignumber"

// Initialize bn.js and ethers.js BigNumber numbers const a = BigNumber.from(2 * 26) const b = new BN(2 * 26, 10) const hash = new BN('dead', 'hex') const dead = BigNumber.from('0xdead')

// Call Rust code with both BN and BigNumber passed and returned console.log(sum(a, b)) // == BigNumber.from(4) console.log(is_dead(hash, dead)) // == true ```

Run example

shell $ cd example $ yarn $ yarn start