formatCurrency static method
Implementation
static String formatCurrency(double value) {
String raw = value.toStringAsFixed(2);
String symbol = 'R\$ ';
List<String> parts = raw.split('.');
String decimalPart = parts.last;
String integerPart = parts.first;
final buffer = StringBuffer()
..write(symbol)
..write(integerPart.replaceAllMapped(RegExp(r'(\d)(?=(\d{3})+(?!\d))'),
(Match match) => '${match.group(0)},'))
..write(',')
..write(decimalPart);
return buffer.toString();
}