Function parse_new 

pub fn parse_new(
    source: &str,
    base_url: &str,
    prev: Option<&PrevParseInfo>,
) -> (Turtle, Vec<TurtleParseError>, PrevParseInfo, TurtleNode, GreenNode)

Parse a Turtle document using the A* error-recovering parser.

Returns the model, parse errors, incremental parse state, and the syntax node.