go-calculator

Requirements

• Go 1.14+
  • for math.FMA()

Usage

$ go run cmd/calculator/main.go
calculator> (2.5 - 1.35) * 2.0
2.3
calculator> -sin((-1+2.5)*pi)
1
calculator> 180*atan2(log(e), log10(10))/pi
45
calculator> exit

You can also use calculator.Calculate() in your application:

package main

import (
	"fmt"
	"log"

	"github.com/mnogu/go-calculator"
)

func main() {
	val, err := calculator.Calculate("(2.5 - 1.35) * 2.0")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(val) // 2.3

	val, err = calculator.Calculate("-sin((-1+2.5)*pi)")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(val) // 1

	val, err = calculator.Calculate("180*atan2(log(e), log10(10))/pi")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(val) // 45
}

References

• chibicc: A small C compiler