Finch/examples/todo.fn

// A tiny to-do list: structs, arrays, strings and files.

struct Task {
    str text
    bool done = false
}

fn show([]Task tasks) {
    if tasks.len == 0 {
        print("(nothing to do)")
    }
    for i in 0..tasks.len {
        mark := " "
        if tasks[i].done {
            mark = "x"
        }
        print("[" + mark + "]", i + 1, tasks[i].text)
    }
}

fn save([]Task tasks, str path) {
    []str lines
    for t in tasks {
        lines.push(str(t.done) + "|" + t.text)
    }
    write_file(path, lines.join("\n"))
}

fn load(str path) -> []Task {
    []Task tasks
    if !file_exists(path) {
        return tasks
    }
    for line in read_file(path).split("\n") {
        if line.len == 0 {
            continue
        }
        parts := line.split("|")
        tasks.push(Task(text: parts[1], done: parts[0] == "true"))
    }
    return tasks
}

fn main() {
    path := "todo.txt"
    tasks := load(path)
    tasks.push(Task(text: "learn Finch"))
    tasks.push(Task(text: "write a game"))
    tasks[0].done = true
    show(tasks)
    save(tasks, path)
    print("saved", tasks.len, "tasks to", path)
}