Update surround commands to work with gap indexing.

1 files changed, 45 insertions, 31 deletions

diff --git a/helix-core/src/surround.rs b/helix-core/src/surround.rs
index 52f60cab..af357c96 100644
--- a/helix-core/src/surround.rs
+++ b/helix-core/src/surround.rs
@@ -1,3 +1,4 @@
+use crate::graphemes::next_grapheme_boundary;
 use crate::{search, Selection};
 use ropey::RopeSlice;
 
@@ -40,23 +41,35 @@ pub fn find_nth_pairs_pos(
 ) -> Option<(usize, usize)> {
     let (open, close) = get_pair(ch);
 
-    let (open_pos, close_pos) = if open == close {
-        let prev = search::find_nth_prev(text, open, pos, n, true);
-        let next = search::find_nth_next(text, close, pos, n, true);
-        if text.char(pos) == open {
-            // cursor is *on* a pair
-            next.map(|n| (pos, n)).or_else(|| prev.map(|p| (p, pos)))?
+    if text.len_chars() < 2 || pos >= text.len_chars() {
+        return None;
+    }
+
+    if open == close {
+        if Some(open) == text.get_char(pos) {
+            // Special case: cursor is directly on a matching char.
+            match pos {
+                0 => Some((pos, search::find_nth_next(text, close, pos + 1, n, true)?)),
+                _ if (pos + 1) == text.len_chars() => Some((
+                    search::find_nth_prev(text, open, pos, n, true)?,
+                    text.len_chars(),
+                )),
+                // We return no match because there's no way to know which
+                // side of the char we should be searching on.
+                _ => None,
+            }
         } else {
-            (prev?, next?)
+            Some((
+                search::find_nth_prev(text, open, pos, n, true)?,
+                search::find_nth_next(text, close, pos, n, true)?,
+            ))
         }
     } else {
-        (
+        Some((
             find_nth_open_pair(text, open, close, pos, n)?,
-            find_nth_close_pair(text, open, close, pos, n)?,
-        )
-    };
-
-    Some((open_pos, close_pos))
+            next_grapheme_boundary(text, find_nth_close_pair(text, open, close, pos, n)?),
+        ))
+    }
 }
 
 fn find_nth_open_pair(
@@ -173,12 +186,13 @@ mod test {
         let slice = doc.slice(..);
 
         // cursor on [t]ext
-        assert_eq!(find_nth_pairs_pos(slice, '(', 6, 1), Some((5, 10)));
-        assert_eq!(find_nth_pairs_pos(slice, ')', 6, 1), Some((5, 10)));
+        assert_eq!(find_nth_pairs_pos(slice, '(', 6, 1), Some((5, 11)));
+        assert_eq!(find_nth_pairs_pos(slice, ')', 6, 1), Some((5, 11)));
         // cursor on so[m]e
         assert_eq!(find_nth_pairs_pos(slice, '(', 2, 1), None);
         // cursor on bracket itself
-        assert_eq!(find_nth_pairs_pos(slice, '(', 5, 1), Some((5, 10)));
+        assert_eq!(find_nth_pairs_pos(slice, '(', 5, 1), Some((5, 11)));
+        assert_eq!(find_nth_pairs_pos(slice, '(', 10, 1), Some((5, 11)));
     }
 
     #[test]
@@ -187,9 +201,9 @@ mod test {
         let slice = doc.slice(..);
 
         // cursor on go[o]d
-        assert_eq!(find_nth_pairs_pos(slice, '(', 13, 1), Some((10, 15)));
-        assert_eq!(find_nth_pairs_pos(slice, '(', 13, 2), Some((4, 21)));
-        assert_eq!(find_nth_pairs_pos(slice, '(', 13, 3), Some((0, 27)));
+        assert_eq!(find_nth_pairs_pos(slice, '(', 13, 1), Some((10, 16)));
+        assert_eq!(find_nth_pairs_pos(slice, '(', 13, 2), Some((4, 22)));
+        assert_eq!(find_nth_pairs_pos(slice, '(', 13, 3), Some((0, 28)));
     }
 
     #[test]
@@ -198,14 +212,14 @@ mod test {
         let slice = doc.slice(..);
 
         // cursor on go[o]d
-        assert_eq!(find_nth_pairs_pos(slice, '\'', 13, 1), Some((10, 15)));
-        assert_eq!(find_nth_pairs_pos(slice, '\'', 13, 2), Some((4, 21)));
-        assert_eq!(find_nth_pairs_pos(slice, '\'', 13, 3), Some((0, 27)));
+        assert_eq!(find_nth_pairs_pos(slice, '\'', 13, 1), Some((10, 16)));
+        assert_eq!(find_nth_pairs_pos(slice, '\'', 13, 2), Some((4, 22)));
+        assert_eq!(find_nth_pairs_pos(slice, '\'', 13, 3), Some((0, 28)));
         // cursor on the quotes
-        assert_eq!(find_nth_pairs_pos(slice, '\'', 10, 1), Some((10, 15)));
+        assert_eq!(find_nth_pairs_pos(slice, '\'', 10, 1), None);
         // this is the best we can do since opening and closing pairs are same
-        assert_eq!(find_nth_pairs_pos(slice, '\'', 0, 1), Some((0, 4)));
-        assert_eq!(find_nth_pairs_pos(slice, '\'', 27, 1), Some((21, 27)));
+        assert_eq!(find_nth_pairs_pos(slice, '\'', 0, 1), Some((0, 5)));
+        assert_eq!(find_nth_pairs_pos(slice, '\'', 27, 1), Some((21, 28)));
     }
 
     #[test]
@@ -214,8 +228,8 @@ mod test {
         let slice = doc.slice(..);
 
         // cursor on go[o]d
-        assert_eq!(find_nth_pairs_pos(slice, '(', 15, 1), Some((5, 24)));
-        assert_eq!(find_nth_pairs_pos(slice, '(', 15, 2), Some((0, 31)));
+        assert_eq!(find_nth_pairs_pos(slice, '(', 15, 1), Some((5, 25)));
+        assert_eq!(find_nth_pairs_pos(slice, '(', 15, 2), Some((0, 32)));
     }
 
     #[test]
@@ -224,9 +238,9 @@ mod test {
         let slice = doc.slice(..);
 
         // cursor on go[o]d
-        assert_eq!(find_nth_pairs_pos(slice, '{', 13, 1), Some((10, 15)));
-        assert_eq!(find_nth_pairs_pos(slice, '[', 13, 1), Some((4, 21)));
-        assert_eq!(find_nth_pairs_pos(slice, '(', 13, 1), Some((0, 27)));
+        assert_eq!(find_nth_pairs_pos(slice, '{', 13, 1), Some((10, 16)));
+        assert_eq!(find_nth_pairs_pos(slice, '[', 13, 1), Some((4, 22)));
+        assert_eq!(find_nth_pairs_pos(slice, '(', 13, 1), Some((0, 28)));
     }
 
     #[test]
@@ -243,7 +257,7 @@ mod test {
             get_surround_pos(slice, &selection, '(', 1)
                 .unwrap()
                 .as_slice(),
-            &[0, 5, 7, 13, 15, 23]
+            &[0, 6, 7, 14, 15, 24]
         );
     }