fixedpoint: positive tester and negative tester

pkg/fixedpoint/filter.go

@@ -0,0 +1,20 @@
+package fixedpoint
+
+type Tester func(value Value) bool
+
+func PositiveTester(value Value) bool {
+	return value.Sign() > 0
+}
+
+func NegativeTester(value Value) bool {
+	return value.Sign() < 0
+}
+
+func Filter(values []Value, f Tester) (slice []Value) {
+	for _, v := range values {
+		if f(v) {
+			slice = append(slice, v)
+		}
+	}
+	return slice
+}

pkg/types/trade_stats.go

@@ -304,6 +304,8 @@ func (s *TradeStats) update() {
 	sort.Sort(fixedpoint.Descending(profitsByOrder))
 	sort.Sort(fixedpoint.Descending(netProfitsByOrder))
 
+	s.Losses = fixedpoint.Filter(profitsByOrder, fixedpoint.NegativeTester)
+	s.Profits = fixedpoint.Filter(profitsByOrder, fixedpoint.PositiveTester)
 	s.LargestProfitTrade = profitsByOrder[0]
 	s.LargestLossTrade = profitsByOrder[len(profitsByOrder)-1]
 	if s.LargestLossTrade.Sign() > 0 {