Quick & Dirty CSV Parsing

ParseCSV.cs

/// <summary>
/// Parse a single line in CSV format.
///
/// This method uses a character looping in lieu of String.Split for performance.  You could
/// squeeze more performance out of it by using .NET 4 MemoryMappedFiles for large reads and
/// possibly pointer arithmatic instead of native C# looping.  Using LinkedList may also help
/// for really large lines.
/// </summary>
/// <param name="line">The line to parse.</param>
/// <param name="delimiter">The delimiter that separates each value. Usually a comma.</param>
/// <param name="qualifier">The encapsulation character of a value.  Usually a double quote.</param>
/// <returns>A list of strings.</returns>
public List<string> ParseCSV(string line, char delimiter, char qualifier)
{
    // The character buffer length
    int iBufferLength = 512;

    // The return list
    List<string> oReturn = new List<string>();

    // Loop through each character
    char   cCurrent;
    bool   bEncapsulated = false;
    char[] acBuffer      = new char[iBufferLength];
    int    iBuffer       = 0;

    for (int i = 0; i < line.Length; i++) {
        cCurrent = line[i];

        if (cCurrent.Equals(qualifier)) {
            bEncapsulated = !bEncapsulated;
            continue;
        }

        if (cCurrent.Equals(delimiter) && !bEncapsulated || line.Length == (i + 1)) {
            if (line.Length == (i + 1)) {
                acBuffer[iBuffer] = cCurrent;
                iBuffer++;
            }

            oReturn.Add(new string(acBuffer, 0, iBuffer));

            Array.Clear(acBuffer, 0, iBufferLength);
            iBuffer = 0;

            continue;
        }

        acBuffer[iBuffer] = cCurrent;
        iBuffer++;
    }
    
    return oReturn;
}