Using the image above we can imagine that we have a mapper which takes elements and changes the color to magenta, thus the blue circle A would be mapped to a magenta circle A, B to B, and C to C.
Note that only the color has been changed.
If we want to do FizzBuzz in F# using a mapper we could do the following (using fsi.exe running against Mono).
> let x = [ 1 .. 31 ];;
val x : int list =
[1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21;
22; 23; 24; 25; 26; 27; 28; 29; 30; 31]
> let fizzBuzzer x =
- match x with
- | x when x % 15 = 0 -> "FizzBuzz"
- | x when x % 3 = 0 -> "Fizz"
- | x when x % 5 = 0 -> "Buzz"
- | x -> x.ToString()
- ;;
val fizzBuzzer : int -> string
> x |> List.map fizzBuzzer;;
val it : string list =
["1"; "2"; "Fizz"; "4"; "Buzz"; "Fizz"; "7"; "8"; "Fizz"; "Buzz"; "11";
"Fizz"; "13"; "14"; "FizzBuzz"; "16"; "17"; "Fizz"; "19"; "Buzz"; "Fizz";
"22"; "23"; "Fizz"; "Buzz"; "26"; "Fizz"; "28"; "29"; "FizzBuzz"; "31"]
In the code above, our list of numbers is x which holds the numbers 1 through 31. We also have a function called fizzBuzzer which takes an int and outputs a string based on the typical FizzBuzz rules. Last we use List.map to do a mapping of fizzBuzzer against x giving us a list of strings with the FizzBuzz rules applied.
Note, we could have done this very easily in one line of F#.
