private void PushEscapedQualifier(FakeStack stack)
{
stack.Push(_escapedQualifier);
}
/// <summary>
/// Reads one row in the stream. Does not care whether there are carriage returns or not.
/// </summary>
/// <returns></returns>
private string[] ReadRow()
{
if (PeekChar() < 0)
{
return(null);
}
List <string> columns = null;
var stack = new FakeStack();
char c = '\0';
bool qualifierStart = false;
bool qualifierEnd = false;
bool newCell = true;
// common operations anonymous helper method
// for a better readability of the algorithm
// Line parsing
while (PeekChar() >= 0)
{
c = (char)ReadChar();
if (newCell)
{
// starting new cell
newCell = false;
if (IsNewLine(c))
{
// empty row
stack.Push(string.Empty);
break;
}
else if (IsCarriageReturn(c))
{
// empty row
if (PeekNewLine())
{
//discard
ReadChar();
}
stack.Push(string.Empty);
break;
}
else if (IsQualifier(c))
{
// text qualified cell
qualifierStart = true;
}
else if (!IsSeparator(c))
{
// first character
stack.Push(c);
}
else
{
// empty cell
AddCell(stack, ref columns, ref newCell, ref qualifierStart, ref qualifierEnd);
}
}
// Text qualifier
else if (IsQualifier(c))
{
// process text qualifier
if (PeekQualifier(stack) && IsQualifierStarted(qualifierStart, qualifierEnd))
{
// needs escaping
// escaped quotes will be resolved when the cell is assembled
stack.Pop();
PushEscapedQualifier(stack);
}
else
{
// add qualifier on the stack
stack.Push(c);
}
}
// Other characters
else
{
// process regular characters
if (PeekQualifier(stack) && IsQualifierStarted(qualifierStart, qualifierEnd))
{
// last qualifier is the closing qualifier
stack.Pop();
stack.Push(string.Empty);
qualifierEnd = true;
}
// old mac or windows EOL
if (IsCarriageReturn(c) && !IsQualifierStarted(qualifierStart, qualifierEnd))
{
if (PeekNewLine())
{
//discard
ReadChar();
}
break;
}
// unix EOL
else if (IsNewLine(c) && !IsQualifierStarted(qualifierStart, qualifierEnd))
{
// end of row
break;
}
else if (IsSeparator(c) && !IsQualifierStarted(qualifierStart, qualifierEnd))
{
// end of cell
AddCell(stack, ref columns, ref newCell, ref qualifierStart, ref qualifierEnd);
}
else
{
// add character on the stack
stack.Push(c);
}
}
}
// left over cell
if (stack.Count > 0 || IsSeparator(c))
{
// last cell
AddCell(stack, ref columns, ref newCell, ref qualifierStart, ref qualifierEnd);
}
string[] arr = null;
if (columns.Count > 0)
{
arr = new string[columns.Count];
columns.CopyTo(arr);
}
return(arr);
//return columns == null ? null : columns.ToArray();
}