C# Split lists simplify code

Question

Goodmorning,

I'm coming from Python environment and turning to c#.

I'm splitting a wider list into narrower lists with a prescribed lenght.

Is there a way to simplify the following code? My guess is that it is a bit quite slow and not properly follows c# common coding rules.

List<object> B = new List<object>();
for(int i = 0; i < SD_Data.Count / 314; i++) {
  var SD_Input = SD_Data.Skip(314 * i).Take(314 * i + 313);
  B.Add(SD_Input);
}

A = B;

I've found this useful way

public static IEnumerable<IEnumerable<T>> Chunk<T > (this IEnumerable<T> source, int chunksize)
{
  while (source.Any())
  {
    yield return source.Take(chunksize);
    source = source.Skip(chunksize);
  }      
}
var z = Chunk(x, 10);

But it does raise the following error:

Error (CS1513): } expected (line 69)
Error (CS1518): Expected class, delegate, enum, interface, or struct (line 88)
Error (CS1518): Expected class, delegate, enum, interface, or struct (line 88)
Error (CS1518): Expected class, delegate, enum, interface, or struct (line 89)
Error (CS1518): Expected class, delegate, enum, interface, or struct (line 89)
Error (CS1518): Expected class, delegate, enum, interface, or struct (line 90)
Error (CS1518): Expected class, delegate, enum, interface, or struct (line 91)
Error (CS1518): Expected class, delegate, enum, interface, or struct (line 92)
Error (CS1518): Expected class, delegate, enum, interface, or struct (line 94)
Error (CS1001): Identifier expected (line 112)
Error (CS1001): Identifier expected (line 114)
Error (CS1022): Type or namespace definition, or end-of-file expected (line 115)

I'm working on the Grasshopper interface of Rhinoceros software from McNeel.

Thanks in advance!

In your second code same, `var z = Chunk(x, 10);` is outside of the method... — DVK, Aug 03 '16 at 13:50

score 1 · Accepted Answer · edited May 23 '17 at 11:51

I finally figured it out.

This thread helped me a lot.

Working with arrays/list with C# components in Grasshopper 3D

The issue was raised since the method was defined inside another method, which is RunScript. The solution is to write it down in the

// <Custom additional code>

code here

// <Custom additional code>

so the result is:

 private void RunScript(List<Point3d> SrcPts, List<string> Instrument, List<object> SD_Data, List<double> XY_Angles, List<string> Octave, ref object A, ref object B)
  {
    B = Chunk(SD_Data, 314);
  }

  // <Custom additional code> 

  public static IEnumerable<IEnumerable<T>> Chunk<T > (IEnumerable<T> source, int chunksize)
  {
    while (source.Any())
    {
      yield return source.Take(chunksize);
      source = source.Skip(chunksize);
    }
  }
  // <Custom additional code>

Thanks all for the valuable tips.

glad you figured it out. Next time please post your entire code (entire method). It helps others help you. — DaniDev, Aug 04 '16 at 22:45

score 0 · Answer 2 · answered Aug 03 '16 at 14:05

0

The syntax to use that method would be this:

var B = SD_Data.Chunk(314);

Chunk is being declared as an Extension Method.

answered Aug 03 '16 at 14:05

sachin

2,341
12
24

Thanks, one issue solved. I'm sorry for the dumb errors, i'm quite newbie in c#. – Eduardo Pignatelli Aug 04 '16 at 21:32

score 0 · Answer 3 · answered Aug 03 '16 at 14:59

Remove the this keyword if you want to call the Chunk method in the standard way

public static IEnumerable<IEnumerable<T>> Chunk<T > (IEnumerable<T> source, int chunksize)
{
  while (source.Any())
  {
    yield return source.Take(chunksize);
    source = source.Skip(chunksize);
  }      
}

C# Split lists simplify code

3 Answers3