// loads a single CSV file, filtering by date
private static void parseSingle(System.Predicate <LocalDate> datePredicate, CharSource resource, IDictionary <LocalDate, ImmutableMap.Builder <FxRateId, FxRate> > mutableMap)
{
try
{
CsvFile csv = CsvFile.of(resource, true);
foreach (CsvRow row in csv.rows())
{
string dateText = row.getField(DATE_FIELD);
LocalDate date = LoaderUtils.parseDate(dateText);
if (datePredicate(date))
{
string currencyPairStr = row.getField(CURRENCY_PAIR_FIELD);
string valueStr = row.getField(VALUE_FIELD);
CurrencyPair currencyPair = CurrencyPair.parse(currencyPairStr);
double value = Convert.ToDouble(valueStr);
ImmutableMap.Builder <FxRateId, FxRate> builderForDate = mutableMap.computeIfAbsent(date, k => ImmutableMap.builder());
builderForDate.put(FxRateId.of(currencyPair), FxRate.of(currencyPair, value));
}
}
}
catch (Exception ex)
{
throw new System.ArgumentException(Messages.format("Error processing resource as CSV file: {}", resource), ex);
}
}