rmbToRMB-rs

Convert RMB/CNY amounts into Chinese uppercase financial text.

这个项目现在由两层组成：

1. Pure Rust library: 可直接被 Rust backend、CLI、WASM 或其他 binding 复用。
2. N-API wrapper: 保留原来的 Node.js 原生扩展能力。

Rust usage

The recommended API is to_rmb_upper_from_cents, because it represents money as an integer number of cents and avoids floating-point precision issues.

use rmb_upper::to_rmb_upper_from_cents;

fn main() {
  let value = to_rmb_upper_from_cents(12_345).unwrap();
  assert_eq!(value, "壹佰贰拾叁元肆角伍分");
}

For decimal strings, use to_rmb_upper_from_str:

use rmb_upper::to_rmb_upper_from_str;

assert_eq!(to_rmb_upper_from_str("123.45").unwrap(), "壹佰贰拾叁元肆角伍分");
assert_eq!(to_rmb_upper_from_str("0.01").unwrap(), "零元壹分");

For cross-language bindings or platforms where large integers may lose precision, use to_rmb_upper_from_cents_str:

use rmb_upper::to_rmb_upper_from_cents_str;

assert_eq!(to_rmb_upper_from_cents_str("12345").unwrap(), "壹佰贰拾叁元肆角伍分");

The f64 adapter exists for compatibility only:

use rmb_upper::to_rmb_upper_from_f64;

assert_eq!(to_rmb_upper_from_f64(123.45).unwrap(), "壹佰贰拾叁元肆角伍分");

Prefer the cents or string APIs for financial code.

Supported range

The maximum supported integer part is:

9999兆9999亿9999万9999

The maximum supported amount in cents is exposed as MAX_CENTS.

Errors

The Rust APIs return Result<String, RmbError>. Possible error variants include:

• NegativeAmount
• NonFiniteAmount
• InvalidFormat
• TooManyDecimalPlaces
• TooLarge

Node.js / N-API usage

The original rmbToRmb(number) API is still available for compatibility. It accepts a JavaScript number and rounds to the nearest cent.

import { rmbToRmb } from '@rs/rmb-to-rmb'

rmbToRmb(123.45) // "壹佰贰拾叁元肆角伍分"

For deterministic formatting, prefer string-based APIs:

import { rmbToRmbFromCents, rmbToRmbFromString } from '@rs/rmb-to-rmb'

rmbToRmbFromCents('12345') // "壹佰贰拾叁元肆角伍分"
rmbToRmbFromString('123.45') // "壹佰贰拾叁元肆角伍分"

Building

Rust library

cargo build
cargo test

N-API wrapper

pnpm i
pnpm build

The N-API build enables the napi feature and compiles the Rust core into a Node.js native addon.

Testing

cargo test

For JavaScript tests:

pnpm test:js

Related projects

• napi-rs