Shopify, formatMoney use current currency dynamically

I am using this script for formatting money in Shopify. The problem is that I’d need the flexibility of having multiple currencies and the current function doesn’t seem to support it.

I’ve tried including that script in a .liquid file, and using {{ currency.symbol }} like: Shopify.money_format = "{{ currency.symbol }}" + "{{amount}}"; or "{{ currency.symbol }}{{amount}}"; or {{ currency.symbol }} + "{{amount}}"; but that gives an error with placeholderRegex which becomes undefined.

Thanks!

EDIT:
This is the code where I use the function:

Shopify.onItemAdded = function(line_item) {
    jQuery.getJSON('/cart.js', function(cart) {
       // change total price
       $('#popup_total').html(Shopify.formatMoney(cart.total_price))
    });
};

EDIT[2]: At the end I went with a different approach. I declared the current currency variable outside the function, and then I replace the original $ symbol, with whatever currency symbol the store has. It goes like this:

var currentCurrency = '{{ cart.currency.symbol }}'

Shopify.onItemAdded = function(line_item) {
    jQuery.getJSON('/cart.js', function(cart) {
         var total = Shopify.formatMoney(cart.total_price).replace('$', currentCurrency)
         $('#popup_total').html(total)
    })
}