golang ,eval parse math , commanf line arguments

args-math.go

package main

import (
	"fmt"
	"os"
	"strings"

	"github.com/apaxa-go/eval"
)

func main() {

	str := os.Args[1]
	exp := strings.Replace(str, "x", "*", -1)

	expr, _ := eval.ParseString(exp, "")

	r, _ := expr.EvalToInterface(nil)

	fmt.Printf("%v %T", r, r) // "3 int8"

}