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/* -*- mode::rust;indent-tabs-mode::nil -*-
* Implementation of 99 Bottles of Beer
* http://99-bottles-of-beer.net/
*/
use std;
import int;
import str;
enum bottle { none, dual, single, multiple(int), }
fn show(b: bottle) {
alt b {
none {
#debug("No more bottles of beer on the wall, \
no more bottles of beer,");
#debug("Go to the store and buy some more, \
99 bottles of beer on the wall.");
}
single {
#debug("1 bottle of beer on the wall, 1 bottle of beer,");
#debug("Take one down and pass it around, \
no more bottles of beer on the wall.");
}
dual {
#debug("2 bottles of beer on the wall, 2 bottles of beer,");
#debug("Take one down and pass it around, \
1 bottle of beer on the wall.");
}
multiple(n) {
#debug("%d bottles of beer on the wall, %d bottles of beer,", n, n);
#debug("Take one down and pass it around, \
%d bottles of beer on the wall.", n-1);
}
}
}
fn next(b: bottle) -> bottle {
alt b {
none { ret none; }
single { ret none; }
dual { ret single; }
multiple(3) { ret dual; }
multiple(n) { ret multiple(n - 1); }
}
}
// Won't need this when tags can be compared with ==
fn more(b: bottle) -> bool { alt b { none { ret false; } _ { ret true; } } }
fn main() {
let mut b: bottle = multiple(99);
let mut running: bool = true;
while running { show(b); #debug(""); running = more(b); b = next(b); }
}
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