Group table rows into sections.

src/intermediate/table.rs

@@ -15,6 +15,12 @@ intermediate!(
     original,
     intermediate_context,
     {
+        // Separate groups by lines, multiple contiguous lines are the same as one.
+        // If there is only one group, it is a tbody.
+        // If there are more than one group, the first is thead and the rest are tbody.
+
+        let sections = group_into_sections(&original.children);
+
         let children = {
             let mut ret = Vec::new();
             for obj in original.children.iter() {
@@ -29,3 +35,41 @@ intermediate!(
         })
     }
 );
+
+enum GroupIntoSectionsState<'orig, 'parse> {
+    NonSection,
+    Section(Vec<&'orig organic::types::TableRow<'parse>>),
+}
+
+fn group_into_sections<'orig, 'parse>(
+    rows: &'orig Vec<organic::types::TableRow<'parse>>,
+) -> Vec<Vec<&'orig organic::types::TableRow<'parse>>> {
+    let mut sections = Vec::new();
+    let mut rows = rows.into_iter();
+    let mut state = GroupIntoSectionsState::NonSection;
+    loop {
+        state = match (state, rows.next()) {
+            (GroupIntoSectionsState::NonSection, None) => break,
+            (GroupIntoSectionsState::NonSection, Some(row)) if row.children.is_empty() => {
+                GroupIntoSectionsState::NonSection
+            }
+            (GroupIntoSectionsState::NonSection, Some(row)) => {
+                GroupIntoSectionsState::Section(vec![row])
+            }
+            (GroupIntoSectionsState::Section(section), None) => {
+                sections.push(section);
+                break;
+            }
+            (GroupIntoSectionsState::Section(section), Some(row)) if row.children.is_empty() => {
+                sections.push(section);
+                GroupIntoSectionsState::NonSection
+            }
+            (GroupIntoSectionsState::Section(mut section), Some(row)) => {
+                section.push(row);
+                GroupIntoSectionsState::Section(section)
+            }
+        }
+    }
+
+    sections
+}