What is inv-sys?

inv-sys is a simple inventory and item keeping system that allows for a type to be stored and counted on a 'per slot' -basis. Built with games in mind, but this could have more use cases. Here is a quick usage guide:

// Implement the Stacksize Trait for your Type that will act as your Item
impl super::Stacksize for char {
    fn get_max_stacksize(&self) -> usize {
        3
    }
}

fn main() {
    // Create the Inventory with a slotsize of 4
    let mut inv = Inv::<char>::new(4);
    // inv-sys works with tuples of the item and an amount.
    // place_at is used to try to place an item at an exact slot
    assert_eq!(
        //Try to place 1 'x' in slot 0
        inv.place_at(('x', 1), 0), 
        None
    );
    // It will return None, because the Item with its amount 
    // could successfully be placed in the inventory

    // See what happens if you try to stack more items, than possible:
    assert_eq!(
        inv.place_at(('x', 3), 0), 
        Some(('x',1))
    );
    // Yes, you have seen correctly! You got one Item back, 
    // because the other ones were used to fill up the slot! 

    // You can get an item from a slot like so:
    // (and we can make sure there are really three Items in slot 0)
    assert_eq!(
        inv.get_slot(0), 
        Some(&('x', 3))
    );

    // You can also stack items quickly. 
    // Stack will look for an incomplete stack of items and fill it first.
    // It will then try to fill the next empty slots, beginning from the start
    assert_eq!(
        inv.stack(('x', 3)), 
        None
    );

    // Fresh Start
    inv = Inv::<char>::new(4);
    // place_at_first_free will only look for free slots, and fill them.
    inv.place_at(('x', 1), 0);
    inv.place_at_first_free(('x', 2));
    assert_eq!(
        inv.get_slot(1), 
        Some(&('x', 2))
    );

    // You can also set a selected slot
    inv.set_selected_slot(1);
    // And decrease the Item Counter
    inv.decrease_selected_slot();
    assert_eq!(
        inv.get_slot(1), 
        Some(&('x', 1))
    );
    // The Item will then become None at amount 0
    inv.decrease_selected_slot();
    assert_eq!(
        inv.get_slot(1), 
        None
    );
}

Roadmap

• Better way to handle item remove/decrease
• Trees for sorting and performance improvements
• Simple configuration options
• Any requests? Please just submit an issue, thanks!

Contributions

Feel free to open an issue/PR explaining possible improvements or changes

Help

Also, please do not hesitate and open an issue when needed. I am happy to help!