A crusty currency converter
$ moneyman convert 50 --from EUR --to PHP --on 2023-05-06 --fallback
50 EUR -> 3044.5833333333350 PHP on the date 2023-05-06
moneyman is also available as a library.
```rust use std::path::PathBuf;
use chrono::NaiveDate; use rustdecimalmacros::dec; use rusty_money::{iso, Money};
fn main() { // Choose where to save the historical data files. let datadir: PathBuf = dirs::homedir() .andthen(|homedir| Some(home_dir.join(".moneyman"))) .expect("need a home directory");
// Fetches the historical data from European Central Bank, and creates an
// exchange store.
let store = moneyman_core::ExchangeStore::sync(data_dir).expect("failed ze sync");
let amount_in_usd = Money::from_decimal(dec!(6500), iso::USD);
let date = NaiveDate::from_ymd_opt(2023, 5, 4).expect("ok date");
// Converts 6,500.00 USD to EUR
let actual = store.convert_on_date(amount_in_usd, iso::EUR, date);
let expected = Money::from_decimal(dec!(5869.6044789597254831135994221), iso::EUR);
// Shouldn't explode? :)
assert_eq!(actual, expected);
} ```
moneyman extends on rusty-money as it already provides a lot of the things like
Money, Currency, ExchangeRate, and Exchange. However, it does not
provide any data to actually convert currency. For historical data, moneyman
uses the European Central Bank, and saves its data to its own local data store.
One important thing to know is that ANY_OTHER_CURRENCY -> EUR is computed with
1/<RATE_OF_ONE_EUR_IN_THAT_OTHER_CURRENCY> since ECB only contains the
EUR -> ANY_OTHER_CURRENCY rates, not vice versa. This [dividing] is most
probably not the behavior observed by RealWord™ currency exchanges. So this
only serves as an approximation at best.