Allow specifying redirects as path start and end

brood/src/commands/path.rs

@@ -11,12 +11,22 @@ fn find_index_of_title(pages: &[Page<PageInfo>], title: &str) -> u32 {
     pages
         .iter()
         .enumerate()
-        .filter(|(_, p)| !p.data.redirect)
         .find(|(_, p)| util::normalize_link(&p.data.title) == title)
         .map(|(i, _)| i)
         .expect("invalid title") as u32
 }
 
+fn resolve_redirects(data: &AdjacencyList<PageInfo, LinkInfo>, mut page_idx: u32) -> u32 {
+    loop {
+        let page = &data.page(page_idx);
+        if page.data.redirect {
+            page_idx = data.link(page.link_idx).to;
+        } else {
+            break page_idx;
+        }
+    }
+}
+
 struct DijkstraPageInfo {
     cost: u32,
     prev_page_idx: u32,
@@ -145,8 +155,8 @@ pub fn path(datafile: &Path, from: &str, to: &str) -> io::Result<()> {
     let pages = data.pages.clone();
 
     println!(">> Locate from and to");
-    let from_idx = find_index_of_title(&pages, from);
+    let from_idx = resolve_redirects(&data, find_index_of_title(&pages, from));
-    let to_idx = find_index_of_title(&pages, to);
+    let to_idx = resolve_redirects(&data, find_index_of_title(&pages, to));
 
     println!(">> Find path");
     let path = dijkstra(data, from_idx, to_idx);

brood/src/data.rs

@@ -214,6 +214,19 @@ impl AdjacencyList<PageInfo, LinkInfo> {
                 panic!("Invalid link detected!");
             }
         }
+
+        // Check that all redirect pages have exactly one link
+        for page_idx in 0..self.pages.len() as u32 - 1 {
+            let page = self.page(page_idx);
+            if page.data.redirect {
+                let start_idx = page.link_idx;
+                let end_idx = self.page(page_idx + 1).link_idx;
+                let n_links = end_idx - start_idx;
+                if n_links != 1 {
+                    panic!("Redirect {:?} has {n_links} links", page.data.title);
+                }
+            }
+        }
     }
 }