@return the deepest open block parser
The column is the position within the line after tab characters have been processed as 4-space tab stops. If the line doesn't contain any tabs, it's the same as the {@link #getIndex()}. If the line starts with a tab, followed by text, then the column for the first character of the text is 4 (the index is 1).
@return the indentation in columns (either by spaces or tab stop of 4), starting from {@link #getColumn()}
@return the current index within the line (0-based)
@return the current line
@return the index of the next non-space character starting from {@link #getIndex()} (may be the same) (0-based)
@return true if the current line is blank starting from the index
State of the parser that is used in block parsers. <p><em>This interface is not intended to be implemented by clients.</em></p>