public static IEnumerable <Bird> Search(this IEnumerable <Bird> source, BirdSearch search)
{
return(source
.Where(s => string.IsNullOrEmpty(search.CommonName) || s.CommonName.Contains(search.CommonName))
.Where(s => string.IsNullOrEmpty(search.Country) || s.Habitats.Any(h => h.Country.Contains(search.Country)))
.Where(s => search.Colors.Any(c => s.PrimaryColor.Equals(c) || s.SecondaryColor.Equals(c)) ||
search.Colors.Join(s.TertiaryColors, sc => sc, tc => tc, (sc, tc) => sc).Any())
.Skip(search.Page * search.PageSize)
.Take(search.PageSize));
}
static void TestBirds()
{
var birds = BirdRepository.LoadBirds();
var sightings = birds.SelectMany(b => b.Sightings);
var avgS = birds.Select(b => b.Sightings.Count()).Average();
var sightingsByCountry = sightings
.GroupBy(s => s.Place.Country)
.Select(g => new { Country = g.Key, Sightings = g.Count() });
var birdCountByStatus = birds
.Where(b => b.ConservationStatus != "LeastConcern" && b.ConservationStatus != "NearThreatened")
.GroupBy(b => b.ConservationStatus)
.Select(selector: g => new { Status = g.Key, Count = g.Count(), Sightings = g.Sum(b => b.Sightings.Count) });
var statuses = birds
.Select(b => b.ConservationStatus)
.Where(s => s != "LeastConcern" && s != "NearThreatened")
.Distinct();
var endangeredSightings = birds
.Join(statuses, b => b.ConservationStatus, s => s, (b, s) => new { Status = s, Sigthings = b.Sightings })
.GroupBy(a => a.Status)
.Select(g => new { Status = g.Key, Sightings = g.Sum(selector: s => s.Sigthings.Count) });
var importedBirds = BirdRepository.LoadImportedBirds();
var matchingBirds = birds.Intersect(importedBirds, new BirdComparer());
// Perform outer join to get elements that exist in one enumerable and not in the other
var newBirds = importedBirds.GroupJoin(birds,
ib => ib.CommonName,
b => b.CommonName,
(ib, b) => new { ImportedBird = ib, Birds = b })
// Variant 1: flatten the grouping first, providing default value for elements with no matches, then filter records
//.SelectMany(gb => gb.Birds.DefaultIfEmpty(), (gb, b) => new { ImportedBird = gb.ImportedBird, Bird = b })
//.Where(a => a.Bird == null)
// Variant 2: filter the grouping directly - my option
.Where(a => a.Birds.Count() == 0)
.Select(a => a.ImportedBird)
.ToList();
var searchParams = new BirdSearch
{
Country = "United States",
Colors = new List <string> {
"White", "Brown", "Black"
},
Page = 0,
PageSize = 5
};
var foundBirds = birds.Search(searchParams);
}