ListExtens.cs

using System;
using System.Collections.Generic;
using System.Runtime.CompilerServices;

namespace Godot.CollectionsExtens.List;

public static partial class ListExt
{
	/// <summary>
	/// Assigns elements of another array into the array. 
	/// Resizes the array to match array. 
	/// Performs type conversions if the array is typed.
	/// </summary>
	/// <param name="p_item">Element.</param>
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static void Assign<T>(this List<T> p_arr, List<T> p_item)
	{
		p_arr.Clear();
		p_arr.AddRange(p_item);
	}

	/// <summary>
	/// Returns the last element of the array. 
	/// Prints an error and returns null if the array is empty.
	/// Note: Calling this function is not the same as writing array[-1]. 
	/// If the array is empty, accessing by index will pause project execution when running from the editor.
	/// </summary>
	/// <returns>The last element of the array.</returns>
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static T Back<T>(this List<T> p_arr) => p_arr[^1];

	/// <summary>
	/// Returns the first element of the array. 
	/// Prints an error and returns null if the array is empty.
	/// Note: Calling this function is not the same as writing array[0]. 
	/// If the array is empty, accessing by index will pause project execution when running from the editor.
	/// </summary>
	/// <returns>The first element of the array.</returns>
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static T Front<T>(this List<T> p_arr)
	{
		return p_arr[0];
	}

	/// <summary>
	/// Removes and returns the element of the array at index position. 
	/// If negative, position is considered relative to the end of the array. 
	/// Leaves the array untouched and returns null if the array is empty or if it's accessed out of bounds. 
	/// An error message is printed when the array is accessed out of bounds, but not when the array is empty.
	/// Note: On large arrays, this method can be slower than pop_back as it will reindex the array's elements 
	/// that are located after the removed element. 
	/// The larger the array and the lower the index of the removed element, the slower pop_at will be.
	/// </summary>
	/// <param name="position">Index position.</param>
	/// <returns>The element of the array at index position.</returns>
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static T PopAt<T>(this List<T> p_arr, int position)
	{
		T element = p_arr[position];
		p_arr.RemoveAt(position);
		return element;
	}

	/// <summary>
	/// Adds an element at the beginning of the array. See also push_back.
	/// Note: On large arrays, this method is much slower than push_back as it will reindex all the array's elements every time it's called. 
	/// The larger the array, the slower push_front will be.
	/// </summary>
	/// <param name="item">Element.</param>
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static void PushFront<T>(this List<T> p_arr, T item)
	{
		p_arr.Insert(0, item);
	}

	/// <summary>
	/// Appends an element at the end of the array. See also push_front.
	/// </summary>
	/// <param name="item">Element.</param>
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static void PushBack<T>(this List<T> p_arr, T item)
	{
		p_arr.Insert(p_arr.Count, item);
	}

	/// <summary>
	/// Removes and returns the first element of the array. 
	/// Returns null if the array is empty, without printing an error message. See also pop_back.
	/// Note: On large arrays, 
	/// this method is much slower than pop_back as it will reindex all the array's elements every time 
	/// it's called. The larger the array, the slower pop_front will be.
	/// </summary>
	/// <returns>The first element of the array.</returns>
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static T PopFront<T>(this List<T> p_arr)
	{
		T firstElement = p_arr[0];
		p_arr.RemoveAt(0);
		return firstElement;
	}

	/// <summary>
	/// Removes and returns the last element of the array. 
	/// Returns null if the array is empty, without printing an error message. 
	/// See also pop_front.
	/// </summary>
	/// <returns>The last element of the array.</returns>
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static T PopBack<T>(this List<T> p_arr)
	{
		T element = p_arr[^1];
		p_arr.RemoveAt(p_arr.Count - 1);
		return element;
	}

	/// <summary>
	/// Executes a provided function once for each array element.
	/// </summary>
	/// <typeparam name="T"></typeparam>
	/// <param name="items"></param>
	/// <param name="action"></param>
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static void ForEach<T>(this IEnumerable<T> items, Action<T> action)
	{
		foreach (T item in items)
			action(item);
	}
}