Bits of .NET

⚡ Span = Memory Performance

Memory allocations slow down apps. Span provides safe, allocation-free access. High-performance, low-allocation code.

📝 Span Basics

// Span from array
int[] numbers = {1, 2, 3, 4, 5};
Span span = numbers.AsSpan();

// Slice
Span slice = span.Slice(1, 3); // {2, 3, 4}

// Modify via span
slice[0] = 10; // numbers becomes {1, 10, 3, 4, 5}

// ReadOnlySpan
ReadOnlySpan readOnly = numbers;

// Span from string (ReadOnlySpan)
ReadOnlySpan text = "Hello World".AsSpan();
ReadOnlySpan word = text.Slice(6, 5); // "World"

// Stackalloc
Span stackSpan = stackalloc int[10];
for (int i = 0; i < stackSpan.Length; i++)
{
    stackSpan[i] = i;
}

🎯 Span Performance

// Fast parsing (no allocations)
public static bool TryParseInt(ReadOnlySpan text, out int result)
{
    result = 0;
    
    if (text.IsEmpty) return false;
    
    int sign = 1;
    int index = 0;
    
    if (text[0] == '-')
    {
        sign = -1;
        index = 1;
    }
    
    for (; index < text.Length; index++)
    {
        if (!char.IsDigit(text[index]))
        {
            return false;
        }
        
        result = result * 10 + (text[index] - '0');
    }
    
    result *= sign;
    return true;
}

✅ Span Benefits

• ✓ Zero allocation (stack-only)
• ✓ High performance
• ✓ Safe (bounds checking)
• ✓ Works with arrays, strings, stack
• ✓ Reduces GC pressure