move view struct out of Context and pass in as a separate argument

 - rename static variables to all caps
 - change index to be Option<usize> rather than i32 where -1 means
   the directory is empty

1 files changed, 1 insertions, 1 deletions

diff --git a/src/history.rs b/src/history.rs
index dd1d939..8ad6619 100644
--- a/src/history.rs
+++ b/src/history.rs
@@ -23,7 +23,7 @@ impl DirHistory {
                     Ok(mut s) => {
                         for (i, dirent) in s.contents.iter().enumerate() {
                             if dirent.path == ancestor {
-                                s.index = i as i32;
+                                s.index = Some(i);
                                 break;
                             }
                         }