package octal

import (
	"errors"
	"math"
)

// ParseOctal takes a string representation of an octal number
// and returns the decimal value of that number, or an error if it
// was unparseable as an octal number
func ParseOctal(v string) (int64, error) {
	var ret float64
	octLen := float64(len(v))
	for i := range v {
		octLen--
		switch {
		case v[i] > 47 && v[i] < 56:
			ret = ret + float64(v[i]-48)*math.Pow(8, octLen)
		default:
			return 0, errors.New("Unparseable as octal")
		}
	}
	return int64(ret), nil
}