package main

import (
	"errors"
)

type proc func(...interface{}) (interface{}, error)

func addition(vals ...interface{}) (interface{}, error) {
	a := accumulator{
		name: "addition",
		floatFn: func(left, right float64) (float64, error) {
			return left + right, nil
		},
		intFn: func(left, right int64) (int64, error) {
			return left + right, nil
		},
	}
	return a.total(vals...)
}

func subtraction(vals ...interface{}) (interface{}, error) {
	a := accumulator{
		name: "subtraction",
		floatFn: func(left, right float64) (float64, error) {
			return left - right, nil
		},
		intFn: func(left, right int64) (int64, error) {
			return left - right, nil
		},
	}
	return a.total(vals...)
}

func multiplication(vals ...interface{}) (interface{}, error) {
	a := accumulator{
		name: "multiplication",
		floatFn: func(left, right float64) (float64, error) {
			return left * right, nil
		},
		intFn: func(left, right int64) (int64, error) {
			return left * right, nil
		},
	}
	return a.total(vals...)
}

func division(vals ...interface{}) (interface{}, error) {
	a := accumulator{
		name: "division",
		floatFn: func(left, right float64) (float64, error) {
			if right == 0.0 {
				return 0.0, errors.New("float division by zero")
			}
			return left / right, nil
		},
		intFn: func(left, right int64) (int64, error) {
			if right == 0 {
				return 0, errors.New("int division by zero")
			}
			return left / right, nil
		},
	}
	return a.total(vals...)
}