Add basic serialization

SaneTsv.cs

@@ -311,6 +311,8 @@ public class SaneTsv
         throw new Exception($"Field {j} on line {line} is not valid UTF-8", e);
       }
 
+      // TODO: Add checking for numeric types format
+
       switch (parsed.ColumnTypes[j])
       {
         case ColumnType.STRING:
@@ -399,6 +401,103 @@ public class SaneTsv
     return parsedFields;
   }
 
+  public static byte[] SerializeSaneTsv(IList<string> header, IList<IList<string>> data)
+  {
+    var escapedString = new StringBuilder();
+
+    // Serialize header
+    for (int i = 0; i < header.Count; i++)
+    {
+      if (header[i].Contains(':'))
+      {
+        throw new Exception($"Column {i} contains the character ':'");
+      }
+
+      for (int j = i + 1; j < header.Count; j++)
+      {
+        if (header[i] == header[j])
+        {
+          throw new Exception("Column names in header must be unique");
+        }
+      }
+
+      for (int j = 0; j < header[i].Count(); j++)
+      {
+        if (header[i][j] == '\n')
+        {
+          escapedString.Append("\\n");
+        }
+        else if (header[i][j] == '\t')
+        {
+          escapedString.Append("\\t");
+        }
+        else if (header[i][j] == '\\')
+        {
+          escapedString.Append("\\\\");
+        }
+        else if (header[i][j] == '#')
+        {
+          escapedString.Append("\\#");
+        }
+        else
+        {
+          escapedString.Append(header[i][j]);
+        }
+      }
+
+      if (i == header.Count - 1)
+      {
+        escapedString.Append('\n');
+      }
+      else
+      {
+        escapedString.Append('\t');
+      }
+    }
+
+    // Serialize data
+    for (int i = 0; i < data.Count; i++)
+    { 
+      for (int j = 0; j < data[i].Count; j++)
+      {
+        for (int k = 0; k < data[i][j].Length; k++)
+        {
+          if (data[i][j][k] == '\n')
+          {
+            escapedString.Append("\\n");
+          }
+          else if (data[i][j][k] == '\t')
+          {
+            escapedString.Append("\\t");
+          }
+          else if (data[i][j][k] == '\\')
+          {
+            escapedString.Append("\\\\");
+          }
+          else if (data[i][j][k] == '#')
+          {
+            escapedString.Append("\\#");
+          }
+          else
+          {
+            escapedString.Append(data[i][j][k]);
+          }
+        }
+
+        if (j < data[i].Count - 1)
+        {
+          escapedString.Append('\t');
+        }
+        else if (i < data.Count - 1)
+        {
+          escapedString.Append('\n');
+        }
+      }
+    }
+
+    return Encoding.UTF8.GetBytes(escapedString.ToString());
+  }
+
   public SaneTsvRecord this[int i] => Records[i];
 
   public class SaneTsvRecord