nim语言实现简单计算器

import strutils
var input: string
var num1: float
var num2: float
var result: float

while true:
  echo "Choose your action:Addition,Subtraction,Multiplication,Division,Exit"
  input = stdin.readLine

  case input:
    of "Addition":
      stdout.write "First number:"  
      num1 = stdin.readLine.parseFloat
      stdout.write "Second number:" 
      num2 = stdin.readLine.parseFloat

      result = num1 + num2
      echo "Result: ", result
    of "Subtraction":
      stdout.write "First number:"  
      num1 = stdin.readLine.parseFloat
      stdout.write "Second number:" 
      num2 = stdin.readLine.parseFloat

      result = num1 - num2
      echo "Result: ", result
    of "Multiplication":
      stdout.write "First number:"  
      num1 = stdin.readLine.parseFloat
      stdout.write "Second number:" 
      num2 = stdin.readLine.parseFloat

      result = num1 * num2
      echo "Result: ", result
    of "Division":
      stdout.write "First number:"  
      num1 = stdin.readLine.parseFloat
      stdout.write "Second number:" 
      num2 = stdin.readLine.parseFloat

      result = num1 / num2
      echo "Result: ", result
    of "Exit":
      break