rename side to kind

internal/kind.go

@@ -0,0 +1,29 @@
+package internal
+
+type Kind uint
+
+const (
+	KindUnknown Kind = iota
+	KindBuy
+	KindSell
+	KindSplit
+)
+
+// String returns a human readable value
+func (d Kind) String() string {
+	switch d {
+	case KindBuy:
+		return "buy"
+	case KindSell:
+		return "sell"
+	case KindSplit:
+		return "split"
+	default:
+		return "unknown"
+	}
+}
+
+// Is returns true when k equals o
+func (k Kind) Is(o Kind) bool {
+	return k == o
+}