tuix_core 0.2.0

use crate::Entity;

pub enum StorageError {
    InvalidEntity,

}

pub struct DenseVec<T> {
    data: Vec<T>,
}

impl<T> DenseVec<T> 
where T: Default + Clone
{

    /// Creates a new instance of a DenseVec storage
    pub fn new() -> Self {
        Self {
            data: Vec::new(),
        }
    }

    /// Inserts an element at position `entity.index()`. If the index is greater than the length of the data array
    /// then the data array will be resized, filling the empty elements between with the default value.
    pub fn insert(&mut self, entity: &Entity, value: T) -> Result<(), StorageError> {
        if let Some(index) = entity.index() {
            
            if index >= self.data.len() {
                self.data.resize(index + 1, T::default());
            }

            self.data[index] = value;

            Ok(())
        } else {
            Err(StorageError::InvalidEntity)
        }
    }

    /// Returns a reference to an element
    pub fn get(&self, entity: &Entity) -> Option<&T> {
        if let Some(index) = entity.index() {
            self.data.get(index)
        } else {
            None
        }
    }

    /// Returns a mutable reference to an element
    pub fn get_mut(&mut self, entity: &Entity) -> Option<&mut T> {
        if let Some(index) = entity.index() {
            self.data.get_mut(index)
        } else {
            None
        }
    }
}