Function prepare_diff 

pub fn prepare_diff(
    left: &DocumentDescriptor,
    right: &DocumentDescriptor,
    whitespace: DiffWhitespace,
    context_lines: Option<usize>,
    syntaxes: &SyntaxRegistry,
) -> Result<PreparedDiff, DocumentError>

Prepare a two-way comparison with default resource limits.

Errors

Returns document or diff budget errors.