Topic: Playing with: Collection Expressions

[gile]

Looks like F#

Code - C#: [Select]

1. > int[] ints = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
2. > ints[3..]
3. int[7] { 3, 4, 5, 6, 7, 8, 9 }
4. > ints[..4]
5. int[4] { 0, 1, 2, 3 }
6. > ints[..^2]
7. int[8] { 0, 1, 2, 3, 4, 5, 6, 7 }

Goodbye Substring() method...

Code - C#: [Select]

1. > string str = "abcdef";
2. > str[3..]
3. "def"
4. > str[..^1]
5. "abcde"
6. > str[2..^2]
7. "cd"

Merge Sort with Span<T> structure.

Code - C#: [Select]

1. static Span<T> MergeSort<T>(Span<T> span) where T : IComparable<T>
2. {
3.     if (span.Length <= 1)
4.         return span;
5.     int middle = span.Length / 2;
6.     return Merge(MergeSort(span[..middle]), MergeSort(span[middle..]));
7. }
8.  
9. static Span<T> Merge<T>(Span<T> left, Span<T> right) where T : IComparable<T>
10. {
11.     int n = left.Length, m = right.Length, i = 0, j = 0, k = 0;
12.     var result = new T[n + m];
13.     while (k < result.Length)
14.     {
15.         result[k++] = (i == n, j == m) switch
16.         {
17.             (true, _) => right[j++],
18.             (_, true) => left[i++],
19.             _ => left[i].CompareTo(right[j]) <= 0 ? left[i++] : right[j++]
20.         };
21.     }
22.     return result;
23. }

Code - C#: [Select]

1. > List<int> unsorted = [6, 7, 9, 1, 8, 3, 5, 0, 4, 2];
2. > List<int> sorted = [.. MergeSort([.. unsorted])];
3. > sorted
4. List<int>(10) { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }