From 1b18f0ba24eaa1e7530063975e64b333d1ed98ea Mon Sep 17 00:00:00 2001
From: Michael Niksa <miniksa@microsoft.com>
Date: Tue, 11 Jun 2024 10:58:17 -0700
Subject: [PATCH] Add ValueTuple based creation of CompressedColumnStorage to
 avoid Tuple allocations

---
 CSparse/Converter.cs                       | 20 ++++++++++++++++++++
 CSparse/Storage/CompressedColumnStorage.cs | 10 ++++++++++
 2 files changed, 30 insertions(+)

diff --git a/CSparse/Converter.cs b/CSparse/Converter.cs
index 131cb91..4285117 100644
--- a/CSparse/Converter.cs
+++ b/CSparse/Converter.cs
@@ -289,5 +289,25 @@ public static CoordinateStorage<T> FromEnumerable<T>(IEnumerable<Tuple<int, int,
 
             return storage;
         }
+
+        /// <summary>
+        /// Convert a row major array to coordinate storage.
+        /// </summary>
+        /// <param name="enumerable">Enumerates the entries of a matrix with value tuples.</param>
+        /// <param name="rowCount">Number of rows.</param>
+        /// <param name="columnCount">Number of columns.</param>
+        /// <returns>Coordinate storage.</returns>
+        public static CoordinateStorage<T> FromEnumerable<T>(IEnumerable<(int, int, T)> enumerable, int rowCount, int columnCount)
+            where T : struct, IEquatable<T>, IFormattable
+        {
+            var storage = new CoordinateStorage<T>(rowCount, columnCount, Math.Max(rowCount, columnCount));
+
+            foreach (var item in enumerable)
+            {
+                storage.At(item.Item1, item.Item2, item.Item3);
+            }
+
+            return storage;
+        }
     }
 }
diff --git a/CSparse/Storage/CompressedColumnStorage.cs b/CSparse/Storage/CompressedColumnStorage.cs
index e6a1b70..f5f81ad 100644
--- a/CSparse/Storage/CompressedColumnStorage.cs
+++ b/CSparse/Storage/CompressedColumnStorage.cs
@@ -153,6 +153,16 @@ public static CompressedColumnStorage<T> OfIndexed(int rows, int columns, IEnume
             return Converter.ToCompressedColumnStorage(c);
         }
 
+        /// <summary>
+        /// Create a new sparse matrix as a copy of the given indexed enumerable using a value tuple.
+        /// </summary>
+        public static CompressedColumnStorage<T> OfIndexed(int rows, int columns, IEnumerable<(int, int, T)> enumerable)
+        {
+            var c = Converter.FromEnumerable<T>(enumerable, rows, columns);
+
+            return Converter.ToCompressedColumnStorage(c);
+        }
+
         /// <summary>
         /// Create a new sparse matrix as a copy of the given array (row-major).
         /// </summary>