Reverted commit: add string[] support.

Author: Nucs

src/NumSharp.Core/Backends/NDArray.String.cs

@@ -32,29 +32,6 @@ public static string AsString(NDArray arr)
             }
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static string[] AsStringArray(NDArray arr)
-        {
-            var chars = arr.ToString();
-            int pos = chars.IndexOf(' ');
-            int numOfRows = int.Parse(chars.Substring(0, pos));
-            int posOfContent = chars.IndexOf(':');
-            string contents = chars.Substring(posOfContent + 1);
-            int[] strLengths = chars.Substring(pos + 1, posOfContent - pos - 1)
-                .Split(' ')
-                .Select(x => int.Parse(x))
-                .ToArray();
-            string[] strArray = new string[numOfRows];
-            int currentPos = 0;
-            for (int i = 0; i < numOfRows; i++)
-            {
-                strArray[i] = contents.Substring(currentPos, strLengths[i]);
-                currentPos += strLengths[i];
-            }
-
-            return strArray;
-        }
-
         /// <summary>
         ///     Get a string out of a vector of chars.
         /// </summary>

src/NumSharp.Core/Creation/np.array.cs

@@ -49,6 +49,34 @@ public static NDArray array(Array array, Type dtype = null, int ndmin = 1, bool
 
         public static NDArray array<T>(params T[] data) where T : unmanaged => new NDArray(ArraySlice.FromArray(data), Shape.Vector(data.Length));
 
+        /// <summary>
+        ///     Create a vector ndarray of type <see cref="char"/>.
+        /// </summary>
+        /// <param name="chars"></param>
+        /// <returns></returns>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static NDArray array(string chars)
+        {
+            if (chars == null)
+                throw new ArgumentNullException(nameof(chars));
+            if (chars.Length == 0)
+                return new NDArray(NPTypeCode.Char, 0);
+
+            unsafe
+            {
+                var ret = new ArraySlice<char>(new UnmanagedMemoryBlock<char>(chars.Length));
+                fixed (char* strChars = chars)
+                {
+                    var src = strChars;
+                    var dst = ret.Address;
+                    var len = sizeof(char) * chars.Length;
+                    Buffer.MemoryCopy(src, dst, len, len);
+                }
+
+                return new NDArray(ret);
+            }
+        }
+
         public static NDArray array<T>(T[][] data)
         {
             var array = data.SelectMany(inner => inner).ToArray(); //todo! not use selectmany.