🎭Force-Statements

Force-Statement Syntax

let <successVar>, <failureVar> = force <expr> with <expr>

A force-statement evaluates the expr between force and with. It must evaluate to (..., error).

• If error != nil:

  • The program will panic with the expr to the right of with

• If error == nil:

  • expression between try and with will be destructured into successVar and failureVar

Working Example

The below code will error, which is intended since force will call panic

Gauntlet

package main

import "fmt" as fmt
import "errors" as errors

fun divide(num1: Int, num2: Int): (Int, Error) {
  if num2 == 0 {
    return (0, errors.new("Cannot divide by 0"))
  }
  return (num1 / num2, null)
}

fun divideBy2(num: Int): (Int, Error) {
  return divide(num, 2)
}

fun divideBy0(num: Int): (Int, Error) {
  return divide(num, 0) 
}

fun getResults(num: Int): (Int, Error) {
  let dBy2Res, dBy2Err = force divideBy2(5) with "Error when dividing 5 by 2"
  let dBy0Res, dBy0Err = force divideBy0(10) with "Error when dividing 10 by 0"
  return (dBy2Res + dBy0Res, null)
}

fun main(): Unit {
  fmt.println("Let's see if there's an error:")
  let res, err = getResults(10)
  fmt.println(err != null)
}

Transpiled

Output