3 files changed, 32 insertions, 53 deletions

diff --git a/helix-core/src/lib.rs b/helix-core/src/lib.rs
index 7b401557..89b82c4e 100644
--- a/helix-core/src/lib.rs
+++ b/helix-core/src/lib.rs
@@ -8,6 +8,7 @@ pub mod macros;
 pub mod object;
 mod position;
 pub mod register;
+pub mod search;
 pub mod selection;
 pub mod state;
 pub mod syntax;
diff --git a/helix-core/src/search.rs b/helix-core/src/search.rs
index 7d790d66..c03f60df 100644
--- a/helix-core/src/search.rs
+++ b/helix-core/src/search.rs
@@ -1,69 +1,39 @@
 use crate::RopeSlice;
 
-pub fn find_nth_next(text: RopeSlice, ch: char, pos: usize, n: usize) -> Option<usize> {
+pub fn find_nth_next(text: RopeSlice, ch: char, mut pos: usize, n: usize) -> Option<usize> {
     // start searching right after pos
-    let mut byte_idx = text.char_to_byte(pos + 1);
-
-    let (mut chunks, mut chunk_byte_idx, _chunk_char_idx, _chunk_line_idx) =
-        text.chunks_at_byte(byte_idx);
-
-    let mut chunk = chunks.next().unwrap_or("");
-
-    chunk = &chunk[(byte_idx - chunk_byte_idx)..];
+    let mut chars = text.chars_at(pos + 1);
 
     for _ in 0..n {
         loop {
-            match chunk.find(ch) {
-                Some(pos) => {
-                    byte_idx += pos;
-                    chunk = &chunk[pos + 1..];
-                    break;
-                }
-                None => match chunks.next() {
-                    Some(next_chunk) => {
-                        byte_idx += chunk.len();
-                        chunk = next_chunk;
-                    }
-                    None => {
-                        log::info!("no more chunks");
-                        return None;
-                    }
-                },
+            let c = chars.next()?;
+
+            pos += 1;
+
+            if c == ch {
+                break;
             }
         }
     }
-    Some(text.byte_to_char(byte_idx))
+
+    Some(pos)
 }
 
-pub fn find_nth_prev(text: RopeSlice, ch: char, pos: usize, n: usize) -> Option<usize> {
+pub fn find_nth_prev(text: RopeSlice, ch: char, mut pos: usize, n: usize) -> Option<usize> {
     // start searching right before pos
-    let mut byte_idx = text.char_to_byte(pos.saturating_sub(1));
-
-    let (mut chunks, mut chunk_byte_idx, _chunk_char_idx, _chunk_line_idx) =
-        text.chunks_at_byte(byte_idx);
-
-    let mut chunk = chunks.prev().unwrap_or("");
-
-    // start searching from pos
-    chunk = &chunk[..=byte_idx - chunk_byte_idx];
+    let mut chars = text.chars_at(pos.saturating_sub(1));
 
     for _ in 0..n {
         loop {
-            match chunk.rfind(ch) {
-                Some(pos) => {
-                    byte_idx = chunk_byte_idx + pos;
-                    chunk = &chunk[..pos];
-                    break;
-                }
-                None => match chunks.prev() {
-                    Some(prev_chunk) => {
-                        chunk_byte_idx -= chunk.len();
-                        chunk = prev_chunk;
-                    }
-                    None => return None,
-                },
+            let c = chars.prev()?;
+
+            pos = pos.saturating_sub(1);
+
+            if c == ch {
+                break;
             }
         }
     }
-    Some(text.byte_to_char(byte_idx))
+
+    Some(pos)
 }
diff --git a/helix-core/src/state.rs b/helix-core/src/state.rs
index d2ebca47..8ff86f0c 100644
--- a/helix-core/src/state.rs
+++ b/helix-core/src/state.rs
@@ -123,6 +123,8 @@ impl State {
     pub fn move_next_word_start(slice: RopeSlice, mut pos: usize, count: usize) -> usize {
         // TODO: confirm it's fine without using graphemes, I think it should be
         for _ in 0..count {
+            // TODO: if end return end
+
             let ch = slice.char(pos);
             let next = slice.char(pos.saturating_add(1));
             if categorize(ch) != categorize(next) {
@@ -148,8 +150,12 @@ impl State {
     pub fn move_prev_word_start(slice: RopeSlice, mut pos: usize, count: usize) -> usize {
         // TODO: confirm it's fine without using graphemes, I think it should be
         for _ in 0..count {
+            if pos == 0 {
+                return pos;
+            }
+
             let ch = slice.char(pos);
-            let prev = slice.char(pos.saturating_sub(1)); // TODO: just return original pos if at start
+            let prev = slice.char(pos - 1);
 
             if categorize(ch) != categorize(prev) {
                 pos -= 1;
@@ -176,6 +182,8 @@ impl State {
 
     pub fn move_next_word_end(slice: RopeSlice, mut pos: usize, count: usize) -> usize {
         for _ in 0..count {
+            // TODO: if end return end
+
             // TODO: confirm it's fine without using graphemes, I think it should be
             let ch = slice.char(pos);
             let next = slice.char(pos.saturating_add(1));
@@ -303,7 +311,7 @@ where
         if !fun(ch) {
             break;
         }
-        *pos += 1;
+        *pos += 1; // TODO: can go 1 over end of doc
     }
 }
 
@@ -319,7 +327,7 @@ where
         if !fun(ch) {
             break;
         }
-        *pos -= 1;
+        *pos -= pos.saturating_sub(1);
     }
 }