Add the sprig functions in the template engine

vendor/github.com/Masterminds/sprig/numeric.go

@@ -0,0 +1,129 @@
+package sprig
+
+import (
+	"math"
+	"reflect"
+	"strconv"
+)
+
+// toFloat64 converts 64-bit floats
+func toFloat64(v interface{}) float64 {
+	if str, ok := v.(string); ok {
+		iv, err := strconv.ParseFloat(str, 64)
+		if err != nil {
+			return 0
+		}
+		return iv
+	}
+
+	val := reflect.Indirect(reflect.ValueOf(v))
+	switch val.Kind() {
+	case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int:
+		return float64(val.Int())
+	case reflect.Uint8, reflect.Uint16, reflect.Uint32:
+		return float64(val.Uint())
+	case reflect.Uint, reflect.Uint64:
+		return float64(val.Uint())
+	case reflect.Float32, reflect.Float64:
+		return val.Float()
+	case reflect.Bool:
+		if val.Bool() == true {
+			return 1
+		}
+		return 0
+	default:
+		return 0
+	}
+}
+
+func toInt(v interface{}) int {
+	//It's not optimal. Bud I don't want duplicate toInt64 code.
+	return int(toInt64(v))
+}
+
+// toInt64 converts integer types to 64-bit integers
+func toInt64(v interface{}) int64 {
+	if str, ok := v.(string); ok {
+		iv, err := strconv.ParseInt(str, 10, 64)
+		if err != nil {
+			return 0
+		}
+		return iv
+	}
+
+	val := reflect.Indirect(reflect.ValueOf(v))
+	switch val.Kind() {
+	case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int:
+		return val.Int()
+	case reflect.Uint8, reflect.Uint16, reflect.Uint32:
+		return int64(val.Uint())
+	case reflect.Uint, reflect.Uint64:
+		tv := val.Uint()
+		if tv <= math.MaxInt64 {
+			return int64(tv)
+		}
+		// TODO: What is the sensible thing to do here?
+		return math.MaxInt64
+	case reflect.Float32, reflect.Float64:
+		return int64(val.Float())
+	case reflect.Bool:
+		if val.Bool() == true {
+			return 1
+		}
+		return 0
+	default:
+		return 0
+	}
+}
+
+func max(a interface{}, i ...interface{}) int64 {
+	aa := toInt64(a)
+	for _, b := range i {
+		bb := toInt64(b)
+		if bb > aa {
+			aa = bb
+		}
+	}
+	return aa
+}
+
+func min(a interface{}, i ...interface{}) int64 {
+	aa := toInt64(a)
+	for _, b := range i {
+		bb := toInt64(b)
+		if bb < aa {
+			aa = bb
+		}
+	}
+	return aa
+}
+
+func until(count int) []int {
+	step := 1
+	if count < 0 {
+		step = -1
+	}
+	return untilStep(0, count, step)
+}
+
+func untilStep(start, stop, step int) []int {
+	v := []int{}
+
+	if stop < start {
+		if step >= 0 {
+			return v
+		}
+		for i := start; i > stop; i += step {
+			v = append(v, i)
+		}
+		return v
+	}
+
+	if step <= 0 {
+		return v
+	}
+	for i := start; i < stop; i += step {
+		v = append(v, i)
+	}
+	return v
+}