public class AutoIndentWriter : IStringTemplateWriter
{
    protected int charPosition;

/// <summary>
/// Essentially a char filter that knows how to auto-indent output
/// by maintaining a stack of indent levels. I set a flag upon newline
/// and then next nonwhitespace char resets flag and spits out indention.
/// The indent stack is a stack of strings so we can repeat original indent
/// not just the same number of columns (don't have to worry about tabs vs spaces then).
/// 
/// Anchors are char positions (tabs won't work) that indicate where all
/// future wraps should justify to. The wrap position is actually the
/// larger of either the last anchor or the indentation level.
/// 
/// This is a filter on a Writer.
/// 
/// It may be screwed up for '\r' '\n' on PC's.
/// </summary>
public class AutoIndentWriter : IStringTemplateWriter
{
    /// <summary>
    /// Track char position in the line (later we can think about tabs).
    /// Indexed from 0. We want to keep <![CDATA[charPosition <= lineWidth]]>.
    /// This is the position we are *about* to write not the position last written to.
    /// </summary>
    protected int charPosition;