Curried, partially applied fizzBuzz Swift

gistfile1.swift

// Declared as a curried function
func fizzBuzzWithOptions(opts:[(divisor: Int, str: String)]) (num: Int) -> String {
    let returnString = opts.reduce(String()) { acc, opt in
        num % opt.divisor == 0 ? acc + opt.str : acc
    }
    return returnString.isEmpty ? String(num) : returnString + "!"
}

// Can be called inline with one argument to map
let array1 = [Int](1...100).map(fizzBuzzWithOptions([(3, "Fizz"), (5, "Buzz")]))
// ["1", "2", "Fizz!", "4", "Buzz!", "Fizz!", "7", "8", "Fizz!" …]


// Or partially applied in advance
let fizzBuzzBar = fizzBuzzWithOptions([(3, "Fizz"), (5, "Buzz"), (7, "Bar")])
let array2 = [Int](1...110).map(fizzBuzzBar)
// ["1", "2", "Fizz!", "4", "Buzz!", "Fizz!", "Bar!", "8", "Fizz!" …]

A Swift FizzBuzz implementation, adapted from ideas found here: http://new.livestream.com/nslondon/events/3336404 by https://twitter.com/abizern
Do watch it - it's very good.

This version uses the same idea presented in the video - a function that takes an array of fizzBuzz options (in tuple form) and an Int parameter - it returns either the Int as a String or an appropriate fizzBuzz string. The advantage of the function is that fizzBuzz can easily be extended by passing in extra options.

This version adds a few extra ideas:

• uses named tuple elements in the function declaration
• implemented without mutable state inside the function
• function is declared in curried form

As the function is curried it can be partially applied, which means it can be passed directly to map - no need for an explicit closure, which makes it a bit nicer to read IMHO.

The linked video also demonstrates fizzBuzz implementations using generators and sequences, so check it out.