How to idiomatically print currency in Clojure?

Question

I'm using the following:

(defn dollars [input] (str "$" (format "%.2f" input)))

(which doesn't do the commas)

But I think there must be a method using pprint/cl-format.

My question is: How to idiomatically print currency in Clojure?

Answer 1

If you have more to work with money, than just formatting it, you might consider using https://github.com/clojurewerkz/money (see the section Formatting), which wrapps joda-money. This not only covers formatting, but also other common problems like rounding.

user=> (mf/format (ma/amount-of mc/USD 10000))
"$10,000.00"
user=> (mf/format (ma/amount-of mc/USD 10000) java.util.Locale/GERMANY)
"USD10.000,00"

edit

You can pass the amount-of means of rounding. E.g.

user=> (mf/format (ma/amount-of mc/USD 10.111111111111111))

ArithmeticException Scale of amount 10.11111111111111 is greater than the scale of the currency USD  org.joda.money.Money.of (Money.java:74)

user=> (mf/format (ma/amount-of mc/USD 10.111111111111111 (java.math.RoundingMode/HALF_DOWN)))
"$10.11"

Answer 2

See also Bankster: https://github.com/randomseed-io/bankster

(money/of :EUR 25)
; => #money[25.00 EUR]

(money/of 25 :EUR)
; => #money[25.00 EUR]

(money/of crypto/BTC 10.1)
; => #money/crypto[10.10000000 BTC]

(money/of BTC 10.1)
; => #money/crypto[10.10000000 BTC]

#money EUR
; => #money[0.00 EUR]

#money/crypto ETH
; => #money/crypto[0.000000000000000000 ETH]

#money[PLN 2.50]
; => #money[2.50 PLN]

#currency USD
; => #currency{:id :USD, :domain :ISO-4217, :kind :FIAT, :numeric 840, :scale 2}

(currency/symbol :USD)
; => "USD"

(currency/symbol :USD :en_US)
; => "$"

(currency/symbol :USDT)
; => "₮"

(currency/name :USDT)
; => "Tether"

(money/format #money[10 EUR])
; => "10,00 €"

(money/format #money[10 EUR] :en_US)
; => "€10.00"

(money/format #money[10 EUR] :pl {:currency-symbol-fn currency/name})
; => "10,00 euro"