1a73671 · urbit.org · git.iko.soy

8# Demo

9

10Here's everyone's favorite whiteboard example,

11−[FizzBuzz](https://en.wikipedia.org/wiki/Fizz_buzz). Each

11+[FizzBuzz](https://en.wikipedia.org/wiki/Fizz_buzz). Each

12line is commented with its number:

13

14```

29$(count (add 1 count)) :: 15

30```

31

32−When FizzBuzz is written in non-functional languages the

32+When FizzBuzz is written in non-functional languages, the

33output is generated as a side effect of the program, e.g., with

34−`printf()`. Hoon is a functional language so technically it

34+`printf()`. Hoon is a functional language, so technically it

35−has no side effects. Accordingly, the code above *returns* a

35+has no side effects. Accordingly, the code above *produces* a

36−list of strings, it doesn't print them. (If you run it from the

36+list of strings; it doesn't print them. (If you run it from the

37Urbit shell, [_Dojo_](../../using/shell), you will of course be

38able to see the product.)

39

72(ii) the number in question, `count`. In case (ii), line 14

73uses the `< >` symbols to convert `count` from an `@` to a `tape`.

74

75−(b) The second value of the pair—i.e., the rest of the output

75+(b) The second value of the pair -- i.e., the rest of the output

76−list—is produced by line 15. This line uses `$()` to loop back

76+list -- is produced by line 15. This line uses `$()` to loop back

77to the `|-` in line 3, but with `count` increased in value by `1`.

78

79You can test this code for yourself by (i) entering `|mount %` in the