TransposedGrid

CSharp.Nixill/src/Collections/Grid/Grid.cs

@@ -226,9 +226,6 @@ public bool Contains(T? item)
     public IEnumerable<(T? Item, GridReference Reference)> Flatten()
       => this.SelectMany((r, y) => r.Select((i, x) => (i, GridReference.XY(x, y))));
 
-    public IEnumerable<(T? Item, GridReference Reference)> FlattenTransposed()
-      => this.Columns.SelectMany((c, x) => c.Select((i, y) => (i, GridReference.XY(x, y))));
-
     public IEnumerator<IEnumerable<T?>> GetColumnEnumerator() => Columns.GetEnumerator();
     public IEnumerator<IEnumerable<T?>> GetEnumerator() => Rows.GetEnumerator();
 

CSharp.Nixill/src/Collections/Grid/GridExtensions.cs

@@ -98,6 +98,9 @@ static IEnumerable<IntVector2> WithTranslations2
       }
     }
   }
+
+  public static IGrid<T> GetTransposedGrid<T>(this IGrid<T> grid)
+    => (grid is TransposedGrid<T> tGrid) ? tGrid.BackingGrid : new TransposedGrid<T>(grid);
 }
 
 public static class GridTransforms

CSharp.Nixill/src/Collections/Grid/IGrid.cs

@@ -151,12 +151,6 @@ public interface IGrid<T> : IEnumerable<IEnumerable<T?>>
     /// </summary>
     IEnumerable<(T? Item, GridReference Reference)> Flatten();
 
-    /// <summary>
-    /// Returns the items and references within a grid as a
-    /// one-dimensional enumerable, columns-first.
-    /// </summary>
-    IEnumerable<(T? Item, GridReference Reference)> FlattenTransposed();
-
     /// <summary>
     /// Returns a single column as a subclass of IList.
     /// </summary>

CSharp.Nixill/src/Collections/Grid/OffsetGrid.cs

@@ -162,9 +162,6 @@ public void Clear()
     public IEnumerable<(T? Item, GridReference Reference)> Flatten()
       => this.SelectMany((r, y) => r.Select((i, x) => (i, GridReference.XY(x - ColumnOffset, y - RowOffset))));
 
-    public IEnumerable<(T? Item, GridReference Reference)> FlattenTransposed()
-      => this.Columns.SelectMany((c, x) => c.Select((i, y) => (i, GridReference.XY(x - ColumnOffset, y - RowOffset))));
-
     public IList<T?> GetColumn(int index) => BackingGrid.GetColumn(index + ColumnOffset);
     public IEnumerator<IEnumerable<T?>> GetColumnEnumerator() => BackingGrid.GetColumnEnumerator();
     public IEnumerator<IEnumerable<T?>> GetEnumerator() => BackingGrid.GetEnumerator();

CSharp.Nixill/src/Collections/Grid/TransposedGrid.cs

@@ -0,0 +1,72 @@
+using System.Collections;
+
+namespace Nixill.Collections;
+
+internal class TransposedGrid<T> : IGrid<T>
+{
+  internal IGrid<T> BackingGrid;
+
+  public TransposedGrid(IGrid<T> grid)
+  {
+    BackingGrid = grid;
+  }
+
+  public T? this[GridReference gr] { get => BackingGrid[gr.Transposed]; set => BackingGrid[gr.Transposed] = value; }
+  public T? this[string gr] { get => BackingGrid[((GridReference)gr).Transposed]; set => BackingGrid[((GridReference)gr).Transposed] = value; }
+  public T? this[int r, int c] { get => BackingGrid[c, r]; set => BackingGrid[c, r] = value; }
+
+  public int Height => BackingGrid.Width;
+  public int Width => BackingGrid.Height;
+  public int Size => BackingGrid.Size;
+
+  public IEnumerable<IEnumerable<T?>> Rows => BackingGrid.Columns;
+  public IEnumerable<IEnumerable<T?>> Columns => BackingGrid.Rows;
+
+  public void AddColumn() => BackingGrid.AddRow();
+  public void AddColumn<U>(IEnumerable<U?> column) where U : T => BackingGrid.AddRow(column);
+  public void AddColumn(T? columnItem) => BackingGrid.AddRow(columnItem);
+  public void AddColumn(Func<T?> columnItemFunc) => BackingGrid.AddRow(columnItemFunc);
+  public void AddColumn(Func<int, T?> columnItemFunc) => BackingGrid.AddRow(columnItemFunc);
+
+  public void AddRow() => BackingGrid.AddColumn();
+  public void AddRow<U>(IEnumerable<U?> row) where U : T => BackingGrid.AddColumn(row);
+  public void AddRow(T? rowItem) => BackingGrid.AddColumn(rowItem);
+  public void AddRow(Func<T?> rowItemFunc) => BackingGrid.AddColumn(rowItemFunc);
+  public void AddRow(Func<int, T?> rowItemFunc) => BackingGrid.AddColumn(rowItemFunc);
+
+  public void Clear() => BackingGrid.Clear();
+  public bool Contains(T item) => BackingGrid.Contains(item);
+
+  public IEnumerable<(T? Item, GridReference Reference)> Flatten()
+    => BackingGrid
+      .Flatten()
+      .OrderBy(t => t.Reference.Column)
+      .ThenBy(t => t.Reference.Row)
+      .Select(t => (t.Item, t.Reference.Transposed));
+
+  public IList<T?> GetColumn(int which) => BackingGrid.GetRow(which);
+
+  public IEnumerator<IEnumerable<T?>> GetColumnEnumerator() => BackingGrid.GetEnumerator();
+  public IEnumerator<IEnumerable<T?>> GetEnumerator() => BackingGrid.GetColumnEnumerator();
+
+  public IList<T?> GetRow(int which) => BackingGrid.GetColumn(which);
+
+  public GridReference? IndexOf(T? item) => BackingGrid.IndexOfTransposed(item)?.Transposed;
+  public GridReference? IndexOfTransposed(T? item) => BackingGrid.IndexOf(item)?.Transposed;
+
+  public void InsertColumn(int before) => BackingGrid.InsertRow(before);
+  public void InsertColumn<U>(int before, IEnumerable<U?> column) where U : T => BackingGrid.InsertRow(before, column);
+  public void InsertColumn(int before, T? columnItem) => BackingGrid.InsertRow(before, columnItem);
+  public void InsertColumn(int before, Func<T?> columnItemFunc) => BackingGrid.InsertRow(before, columnItemFunc);
+  public void InsertColumn(int before, Func<int, T?> columnItemFunc) => BackingGrid.InsertRow(before, columnItemFunc);
+
+  public void InsertRow(int before) => BackingGrid.InsertColumn(before);
+  public void InsertRow<U>(int before, IEnumerable<U?> row) where U : T => BackingGrid.InsertColumn(before, row);
+  public void InsertRow(int before, T? rowItem) => BackingGrid.InsertColumn(before, rowItem);
+  public void InsertRow(int before, Func<T?> rowItemFunc) => BackingGrid.InsertColumn(before, rowItemFunc);
+  public void InsertRow(int before, Func<int, T?> rowItemFunc) => BackingGrid.InsertColumn(before, rowItemFunc);
+
+  public bool IsWithinGrid(GridReference reference) => BackingGrid.IsWithinGrid(reference.Transposed);
+
+  IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+}