Add package for formatting floats with certain decimal precision

util/nums/nums.go

@@ -0,0 +1,63 @@
+// Copyright © 2016 Abcum Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package nums
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+func CountPlaces(v float64) int {
+
+	s := strconv.FormatFloat(v, 'f', -1, 64)
+	i := strings.IndexByte(s, '.')
+
+	if i > -1 {
+		return len(s) - i - 1
+	}
+
+	return 0
+
+}
+
+func FormatPlaces(v float64, p int) float64 {
+
+	switch p {
+	case 0:
+		return float64(int(v))
+	case 1:
+		f := fmt.Sprintf("%.1f", v)
+		o, _ := strconv.ParseFloat(f, 64)
+		return o
+	case 2:
+		f := fmt.Sprintf("%.2f", v)
+		o, _ := strconv.ParseFloat(f, 64)
+		return o
+	case 3:
+		f := fmt.Sprintf("%.3f", v)
+		o, _ := strconv.ParseFloat(f, 64)
+		return o
+	case 4:
+		f := fmt.Sprintf("%.4f", v)
+		o, _ := strconv.ParseFloat(f, 64)
+		return o
+	default:
+		f := fmt.Sprintf("%.5f", v)
+		o, _ := strconv.ParseFloat(f, 64)
+		return o
+	}
+
+}