As the question states, compiling and running the 2 files below makes the compiler hang indefinitely. Here are the CLI commands I have tried: swiftc *.swift -o combined &&./combined
and cat *.swift | swift -
cat *.swift | swift -
.
The only 2 swift files in the directory are main.swift
and Vehicle.swift
.
I have tried compiling and running both files separately, Vehicle.class
has no errors and compiles properly, main.swift
has a error: cannot find 'Vehicle' in scope
error, which is understandable since I need to compile them together. There is no other feedback from the compiler. What can cause the compiler to hang?
Code:
main.swift
// Stub program to demonstrate the Vehicle class
let vehicle1 = Vehicle(newNumOfDoors: 4, newMaxSpeed: 150,
newLicensePlate: "ASDF404", newColour: "Red")
vehicle1.licensePlate = "FGHJ968"
vehicle1.colour = "Green"
vehicle1.accelerate(accelerateBy: 60)
print("\nLicense Plate: " + vehicle1.licensePlate
+ "\nColour: " + vehicle1.colour
+ "\nNumber of Doors: " + vehicle1.numOfDoors
+ "\nMax Speed: " + vehicle1.maxSpeed
+ "\nCurrent Speed: " + vehicle1.speed)
Vehicle.swift
public class Vehicle {
// Properties Declaration
let numOfDoors: Int
let maxSpeed: Int
private(set) var speed: Int
var licensePlate: String
var colour: String
// Initializes a Vehicle
init (newNumOfDoors: Int, newMaxSpeed: Int,
newLicensePlate: String, newColour: String) {
self.numOfDoors = newNumOfDoors
self.licensePlate = newLicensePlate
self.maxSpeed = newMaxSpeed
self.colour = newColour
self.speed = 0
}
func accelerate(accelerateBy: Int) {
self.speed += accelerateBy
}
func brake(brakeBy: Int) {
self.speed -= brakeBy
}
}
The compiler is having issues with your print
statement (which I determined by removing elements from the program until it worked). This is likely because it's struggling to figure out the type when using +
to concatenate everything.
One option is to use a multi-line string literal:
let vehicle1 = Vehicle(newNumOfDoors: 4, newMaxSpeed: 150,
newLicensePlate: "ASDF404", newColour: "Red")
vehicle1.licensePlate = "FGHJ968"
vehicle1.colour = "Green"
vehicle1.accelerate(accelerateBy: 60)
let str = """
License Plate: \(vehicle1.licensePlate)
Colour: \(vehicle1.colour)
Number of Doors: \(vehicle1.numOfDoors)
Max Speed: \(vehicle1.maxSpeed)
Current Speed: \(vehicle1.speed)
"""
print(str)
Another option is to use interpolation rather than the +
:
print("\nLicense Plate: \(vehicle1.licensePlate)"
+ "\nColour: \(vehicle1.colour)"
+ "\nNumber of Doors: \(vehicle1.numOfDoors)"
+ "\nMax Speed: \(vehicle1.maxSpeed)"
+ "\nCurrent Speed: \(vehicle1.speed)")
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