using System;
using System.Collections.Generic;
using System.Linq;

namespace MarkovGrams.Utilities
{
	public static class LinqExtensions
	{
		public static void ForEach<T>(this IEnumerable<T> enumerable, Action<T> action)
		{
			foreach (T item in enumerable)
			{
				action(item);
			}
		}

		public static T ShiftAt<T>(this List<T> list, int index)
		{
			T item = list[index];
			list.RemoveAt(index);
			return item;
		}

		public static int CountCharInstances(this string str, char[] targets)
		{
			int result = 0;
			for (int i = 0; i < str.Length; i++) {
				for (int t = 0; t < targets.Length; t++)
					if (str[i] == targets[t]) result++;
			}
			return result;
		}

		public static bool StartsWithFast(this string str, string target)
		{
			if (str.Length < target.Length) return false;
			return str.Substring(0, target.Length) == target;
		}
	}
}