added read column by Column Name

j0nimost · Oct 17, 2023 · 56feff4 · 56feff4
1 parent acef17c
commit 56feff4
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Showing 3 changed files with 51 additions and 4 deletions.
diff --git a/README.md b/README.md
@@ -51,13 +51,15 @@ To also make it easier you can jump to a specific Row and Col
 
 Example:
 ```c#
-       var stream = new MemoryStream(Encoding.UTF8.GetBytes(sampleCSV));
+        var stream = new MemoryStream(Encoding.UTF8.GetBytes(sampleCSV));
 
-       using var rows = Kafa.Read(stream);
+        using var rows = Kafa.Read(stream);
 
-       var result = rows[0].Cols[0].ToString();
+        var result = rows[0].Cols[0].ToString();
+            // or
+        var result2 = rows[new Index(0)].Cols[new Index(0)].ToString();
             // or
-       var result2 = rows[new Index(0)].Cols[new Index(0)].ToString();
+        var result3 = row[0].Cols["date"].ToString(); // read Column by Name
 ```
 #### `IEnumerable<T>`
 Understanding that many users want a simple easy to use experience the library allows

diff --git a/src/Kafa/Reader/KafaReader.Col.cs b/src/Kafa/Reader/KafaReader.Col.cs
@@ -25,6 +25,12 @@ public Col(ColEnumerable colEnumerable, int index)
 
             }
 
+            public Col(ColEnumerable colEnumerable, string columnName)
+            {
+                _colEnumerable = colEnumerable;
+                int index = _colEnumerable.ReadColByHeader(columnName);
+                Value = _colEnumerable.ReadColSpan(index);
+            }
 
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
             public T Parse<T>() where T : ISpanParsable<T> => _colEnumerable.Parse<T>(Value);
@@ -57,6 +63,19 @@ public ColEnumerable(KafaReader reader, int startColIndex, int length)
 
             public Col this[Index index] => new(this, index.GetOffset(this.Length));
 
+            public Col this[string columnName] => new(this, columnName);
+
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            public int ReadColByHeader(string columnName)
+            {
+                if(_reader.Headers != null && _reader.Headers.Contains(columnName))
+                {
+                    return (int)_reader.Headers[columnName]!;
+                }
+
+                throw new KafaException($"{columnName} Not Found");
+            }
+
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
             public ReadOnlySpan<char> ReadColSpan(int index)
             {

diff --git a/src/KafaTests/KafaReadTests.cs b/src/KafaTests/KafaReadTests.cs
@@ -171,6 +171,21 @@ public void ReadColByIndexStruct(string sampleCSV)
             Assert.Equal("AAL", rows[new Index(2)].Cols[new Index(6)].ToString());
         }
 
+
+        [Theory]
+        [MemberData(nameof(GetObjects))]
+        public void ReadColByColumnName(string sampleCSV)
+        {
+            var stream = new MemoryStream(Encoding.UTF8.GetBytes(sampleCSV));
+
+            using var rows = Kafa.Read(stream);
+            Assert.NotEmpty(rows);
+            Assert.Equal("2013-02-08", rows[1].Cols["date"].ToString());
+            Assert.Equal("15.12", rows[1].Cols["high"].ToString());
+            Assert.Equal("AAL", rows[3].Cols["Name"].ToString());
+            Assert.Equal("AAL", rows[2].Cols["Name"].ToString());
+        }
+
         [Theory]
         [MemberData(nameof(GetObjects))]
         public void ReadRowOutOfRange(string sampleCSV)
@@ -192,6 +207,17 @@ public void ReadColOutOfRange(string sampleCSV)
             Assert.Throws<KafaException>(() => rows[0].Cols[-1].ToString());
         }
 
+
+        [Theory]
+        [MemberData(nameof(GetObjects))]
+        public void ReadColNameNotFound(string sampleCSV)
+        {
+            var stream = new MemoryStream(Encoding.UTF8.GetBytes(sampleCSV));
+            using var rows = Kafa.Read(stream);
+            Assert.NotEmpty(rows);
+            Assert.Throws<KafaException>(() => rows[0].Cols["city"].ToString());
+        }
+
         [Fact]
         public void ReadUnequalRowSize()
         {