day2.nt

module day2;

macro import neat.macros.listcomprehension;
macro import neat.macros.assert;

import std.stdio;
import std.file;
import std.string;

alias command = (
    :forward, int |
    :down, int |
    :up, int);

command parse(string line) {
    auto parts = line.split(" ");
    if (parts[0] == "forward") return (:forward, parts[1].atoi);
    else if (parts[0] == "down") return (:down, parts[1].atoi);
    else if (parts[0] == "up") return (:up, parts[1].atoi);
    else assert(false);
}

void main() {
    auto lines = "day2.txt".readText.split("\n");
    auto commands = [line.parse for line in lines where line.length];
    // todo reduce/fold
    mut int progress = 0;
    mut int depth = 0;
    for (command in commands) command.case {
        (:forward, int fwd): progress += fwd;
        (:down, int down): depth += down;
        (:up, int up): depth -= up;
    }
    print("progress $progress, depth $depth, result $(progress * depth)");
}