Add some comments about the node split method

Author: vidy

examples/text.rs

@@ -14,9 +14,9 @@ fn main() {
             for line in run.lines {
                 for word in line.words {
                     println!("{}", word.text.as_str());
-                    for char in word.chars {
-                        println!("{:?}", char);
-                    }
+                    // for char in word.chars {
+                    //     println!("{:?}", char);
+                    // }
                 }
             }
         }

src/node.rs

@@ -201,8 +201,11 @@ fn split<E: Encoder>(boxes: &mut [(RectF, usize)], spans: &[TextSpan<E>], lines:
     }
 
     let tag = match (y_gaps.is_empty(), x_gaps.is_empty()) {
+        // N y gaps, whatever x_gap is, if cells are all lines, then it is a line
         (true, _) if cells.iter().all(|n| n.tag() <= NodeTag::Line) => NodeTag::Line,
+        // N x gaps, whatever y_gap is, if cells are all lines, then it is a paragraph
         (_, true) if cells.iter().all(|n| n.tag() <= NodeTag::Line) => NodeTag::Paragraph,
+        // Otherwise it is a complex node
         _ => NodeTag::Complex
     };