Public implementation of ropes in C#?

Question

Is there a public implementation of the Rope data structure in C#?

Answer 1

The BigList class from Wintellect Power Collections (a C# data structure library) is somehow similar to rope: http://docs.pushtechnology.com/docs/4.5.7/dotnet/externalclient/html/class_wintellect_1_1_power_collections_1_1_big_list_3_01_t_01_4.html

I measured its performance and it performs pretty well in "start of string inserts":

const int InsertCount = 150000;

var startTime = DateTime.Now;
var ropeOfChars = new BigList();
for (int i = 0; i < InsertCount; i++)
{
    ropeOfChars.Insert(0, (char)('a' + (i % 10)));
}
Console.WriteLine("Rope time: {0}", DateTime.Now - startTime);

startTime = DateTime.Now;
var stringBuilder = new StringBuilder();
for (int i = 0; i < InsertCount; i++)
{
    stringBuilder.Insert(0, (char)('a' + (i % 10)));
}
Console.WriteLine("StringBuilder time: {0}", DateTime.Now - startTime);

Results:

Rope time: 00:00:00.0468740
StringBuilder time: 00:00:05.1471300

But it performs not well in "middle of string inserts":

const int InsertCount = 150000;

var startTime = DateTime.Now;
var ropeOfChars = new BigList();
for (int i = 0; i < InsertCount; i++)
{
    ropeOfChars.Insert(ropeOfChars.Count / 2, (char)('a' + (i % 10)));
}
Console.WriteLine("Rope time: {0}", DateTime.Now - startTime);

startTime = DateTime.Now;
var stringBuilder = new StringBuilder();
for (int i = 0; i < InsertCount; i++)
{
    stringBuilder.Insert(stringBuilder.Length / 2, (char)('a' + (i % 10)));
}
Console.WriteLine("StringBuilder time: {0}", DateTime.Now - startTime);

Results:

Rope time: 00:00:15.0229452
StringBuilder time: 00:00:04.7812553

I am not sure if this is a bug or unefficient implementation, but "rope of chars" is expected to be faster that StringBuilder in C#.

You can install Power Collections from NuGet:

Install-Package XAct.Wintellect.PowerCollections