Solutions

Here are the solutions to the exercises provided in the previous section. Use them to ensure your understanding and to correct any mistakes you might have made.

Solution 1

First, we compose these functions to create a transaction processing pipeline:

Func<IEnumerable<EnemyWave>, IEnumerable<string>> processEnemyWaves = waves =>
     waves
         .Where(validateWave)
         .Select(applyHardMode)
         .Select(formatWave);

Then, we test it:

var enemyWaves = new List<EnemyWave>
{
     new EnemyWave { WaveNumber = 1, EnemyCount = 50, Description = "Initial wave" },
     new EnemyWave { WaveNumber = 2, EnemyCount = 0, Description = "Empty wave" },
     new EnemyWave { WaveNumber...