Complete documentation for MatrixMarketReader

* Might be changed in the future as it's currently unclear when
  checkHeader returns true

src/SparseTransform/Convert/MatrixMarketReader.cs

@@ -4,9 +4,11 @@ using Transform.Convert;
 
 namespace SparseTransform.Convert
 {
+    /// <summary>
+    /// Provides an IReader implementation to read a MatrixMarket string.
+    /// </summary>
     internal class MatrixMarketReader : IReader
     {
-
         public IGraph ReadGraph(string matrix)
         {
             string[] lines = matrix.Split(
@@ -57,7 +59,7 @@ namespace SparseTransform.Convert
         /// checks with ANTLR4.0 whether the header is a valid instance. The header grammar can be found in the file MMFHeader.g4 
         /// </summary>
         /// <param name="header">header of the MMF-input</param>
-        /// <returns></returns>
+        /// <returns>true if matrix is not symmetric</returns>
         private bool checkHeader(string header)
         {
             AntlrInputStream stream = new AntlrInputStream(header);
@@ -70,7 +72,6 @@ namespace SparseTransform.Convert
             return visitor.Visit(speakParser.header());
         }
 
-
        /// <summary>
        /// checks whether the comment-section is valid.
        /// </summary>
@@ -102,7 +103,6 @@ namespace SparseTransform.Convert
             }
         }
 
-
         /// <summary>
         /// creates a graph from the data-section of the MMF-input and meanwhile checks whether the data-section is valid
         /// </summary>
@@ -135,8 +135,6 @@ namespace SparseTransform.Convert
             }
         }
 
-
-
         /// <summary>
         /// computes the first data-line in the MMF-input 
         /// </summary>

src/SparseTransform/Convert/VisitorHeader.cs

@@ -11,7 +11,7 @@ namespace Transform.Convert
         /// visits the AST and helps to decide whether the input matrix is symmetric
         /// </summary>
         /// <param name="context"></param>
-        /// <returns></returns>
+        /// <returns>true if the input matrix is not symmetric</returns>
         public override bool VisitHeader([NotNull] MMFHeaderParser.HeaderContext context)
         {
             if ((context.format().choice1() is null || context.format().choice1().GENERAL() is null)