using System.Collections.Generic; using System.IO; namespace Core { public static class Extensions { public static string Canonicalize(this string s) { return s.ToUpperInvariant(); } public static IEnumerable GetFileLines(this string filename) { using (var sr = File.OpenText(filename)) { while (true) { var line = sr.ReadLine(); if (line == null) yield break; yield return line; } } } } }