Gee

Evalute math and logical string expressions

What is supported?

• Math Operations:
  • Add (+)
  • Substract (-)
  • Multiply (*)
  • Divide (/)
  • Pow (^)
• Logical Operations:
  • And (&&)
  • Or (||)
  • Greater (>)
  • Greater Than (>=)
  • Less (<)
  • Less Than (<=)
  • Equals (==)
  • Not equals (!=)
  • Not (!)
  • True Value (True)
  • False Value (False)
• Misc:
  • Braces Open (( )
  • Braces Close ())

What is not supported?

precedence is currently not supported. So multiplicate does not happen before addition, substraction, etc. To simulate this behaviour you can use braces.

Numbers are currently only returned as float64, might add the option, that int can be returned.

How to use

Import the modul:

go get github.com/0x3alex/gee

And then call gee.Eval().

Eval() returns (int, any, error)

• int describes the returned data type
  • 0 means float64
  • 1 means bool
  • 2 means string
• any the result
• error is set, if an error occurred while executing eval

Example program

package main

import (
	"bufio"
	"fmt"
	"log"
	"os"
	"strings"

	"github.com/0x3alex/gee"
)

func main() {
	reader := bufio.NewReader(os.Stdin)
	for {
		fmt.Print("Enter text: ")
		text, _ := reader.ReadString('\n')
		if strings.TrimSpace(strings.ToLower(text)) == "exit" {
			return
		}
		t, v, err := gee.Eval(text)
		if err != nil {
			log.Fatalf(err.Error())
		}
		switch t {
		case 0:
			fmt.Printf("%.2f\n", v.(float64))
		case 1:
			println(v.(bool))
		case 2:
			println(v.(string))
		}
	}

}