float.go

package cast

import (
	"fmt"
	"strconv"
)

// ToFloat64 casts an interface to a float64 type, discarding any errors.
func ToFloat64(i interface{}) float64 {
	ret, _ := ToFloat64E(i)
	return ret
}

// ToFloat64E casts an interface to a float64 type.
func ToFloat64E(i interface{}) (float64, error) {
	i = indirect(i)

	switch s := i.(type) {
	case float64:
		return s, nil
	case float32:
		return float64(s), nil
	case int:
		return float64(s), nil
	case int64:
		return float64(s), nil
	case int32:
		return float64(s), nil
	case int16:
		return float64(s), nil
	case int8:
		return float64(s), nil
	case uint:
		return float64(s), nil
	case uint64:
		return float64(s), nil
	case uint32:
		return float64(s), nil
	case uint16:
		return float64(s), nil
	case uint8:
		return float64(s), nil
	case string:
		v, err := strconv.ParseFloat(s, 64)
		if err == nil {
			return v, nil
		}
		return 0, fmt.Errorf("unable to cast %#v of type %T to float64", i, i)
	case bool:
		if s {
			return 1, nil
		}
		return 0, nil
	default:
		return 0, fmt.Errorf("unable to cast %#v of type %T to float64", i, i)
	}
}

// ToFloat32 casts an interface to a float32 type, discarding any errors.
func ToFloat32(i interface{}) float32 {
	ret, _ := ToFloat32E(i)
	return ret
}

// ToFloat32E casts an interface to a float32 type.
func ToFloat32E(i interface{}) (float32, error) {
	i = indirect(i)

	switch s := i.(type) {
	case float64:
		return float32(s), nil
	case float32:
		return s, nil
	case int:
		return float32(s), nil
	case int64:
		return float32(s), nil
	case int32:
		return float32(s), nil
	case int16:
		return float32(s), nil
	case int8:
		return float32(s), nil
	case uint:
		return float32(s), nil
	case uint64:
		return float32(s), nil
	case uint32:
		return float32(s), nil
	case uint16:
		return float32(s), nil
	case uint8:
		return float32(s), nil
	case string:
		v, err := strconv.ParseFloat(s, 32)
		if err == nil {
			return float32(v), nil
		}
		return 0, fmt.Errorf("unable to cast %#v of type %T to float32", i, i)
	case bool:
		if s {
			return 1, nil
		}
		return 0, nil
	default:
		return 0, fmt.Errorf("unable to cast %#v of type %T to float32", i, i)
	}
}