Combining consecutive dates into ranges

Question

I have a List of objects

public class sample
{
 public DateTime Date;
 public string content;
}

I want to be able to create a list of new o

Answer 1

Here's a non-Linq way to do it:

List groups = new List();  
sampleWithIntervals curGroup = null;

foreach(sample s in samples.OrderBy(sa => sa.content).ThenBy(sa => sa.Date))
{
    if(curGroup == null || // first group
        s.Date != curGroup.endDate.AddDays(1) ||
        s.content != curGroup.content   // new group
      ) 
    {
        curGroup = new sampleWithIntervals() {startDate = s.Date, endDate = s.Date, content = s.content};
        groups.Add(curGroup);
    }
    else
    {
        // add to current group
        curGroup.endDate = s.Date;
    }
}

You can do this with Linq using a trick that groups the items by the date minus the index to group consecutive items:

samples.OrderBy(s => s.content)   
       .ThenBy(s => s.Date)
       // select each item with its index
       .Select ((s, i) => new {sample = s, index = i})  
       // group by date miuns index to group consecutive items
       .GroupBy(si => new {date = si.sample.Date.AddDays(-si.index), content = si.sample.content})  
       // get the min, max, and content of each group
       .Select(g => new sampleWithIntervals() {
                        startDate = g.Min(s => s.sample.Date), 
                        endDate = g.Max(s => s.sample.Date), 
                        content = g.First().sample.content
                        })