An ordinal list is a list optimized to store lists of integer data that can then be manipulated as a set with intersect/union etc. Each integer stored is translated to a bit offset and thus cann't be stored more than once or in any particular order. Note: adding the value int.Max will allocate int.Max/8 bytes of memory, so this is best used with ordinal indexes into a list that is smaller than 8,388,608 (one megabyte of bits). Pre-allocate with Ceiling = max for better performance, or add the integers in reverse order (highest to lowest).
Syntax
| Visual Basic (Declaration) | |
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Public Class OrdinalList |
| C# | |
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public class OrdinalList |
Example
Previously it was thought to be invalid to set a negative ceiling; however, since ceiling is an 'inclusive' value, the value of '0' actually requires 1 byte to be allocated. In order to allow explicitly clearing the array length, a -1 must be allowed;
Library/Library.Test/TestOrdinalList.cs
| C# |  Copy Code |
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OrdinalList list = new OrdinalList();
list.Ceiling = -1;
Assert.AreEqual(-1, list.Ceiling); |
| VB.NET | Copy Code |
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Dim list As New OrdinalList()
list.Ceiling = -1
Assert.AreEqual(-1, list.Ceiling) |
Inheritance Hierarchy
Requirements
Target Platforms: Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, Windows 7
See Also
