5 files changed, 235 insertions, 223 deletions

diff --git a/helix-core/src/lib.rs b/helix-core/src/lib.rs
index 81a35f10..a742ca13 100644
--- a/helix-core/src/lib.rs
+++ b/helix-core/src/lib.rs
@@ -5,6 +5,7 @@ pub mod graphemes;
 mod history;
 pub mod indent;
 pub mod macros;
+pub mod movement;
 pub mod object;
 mod position;
 pub mod register;
@@ -48,7 +49,7 @@ pub use tendril::StrTendril as Tendril;
 #[doc(inline)]
 pub use {regex, tree_sitter};
 
-pub use position::Position;
+pub use position::{coords_at_pos, pos_at_coords, Position};
 pub use selection::Range;
 pub use selection::Selection;
 pub use syntax::Syntax;
diff --git a/helix-core/src/movement.rs b/helix-core/src/movement.rs
new file mode 100644
index 00000000..57abc498
--- /dev/null
+++ b/helix-core/src/movement.rs
@@ -0,0 +1,157 @@
+use crate::graphemes::{nth_next_grapheme_boundary, nth_prev_grapheme_boundary, RopeGraphemes};
+use crate::{coords_at_pos, pos_at_coords, ChangeSet, Position, Range, Rope, RopeSlice, Selection};
+
+pub fn move_next_word_start(slice: RopeSlice, mut pos: usize, count: usize) -> usize {
+    for _ in 0..count {
+        if pos + 1 == slice.len_chars() {
+            return pos;
+        }
+
+        let mut ch = slice.char(pos);
+        let next = slice.char(pos + 1);
+
+        // if we're at the end of a word, or on whitespce right before new one
+        if categorize(ch) != categorize(next) {
+            pos += 1;
+            ch = next;
+        }
+
+        if is_word(ch) {
+            skip_over_next(slice, &mut pos, is_word);
+        } else if ch.is_ascii_punctuation() {
+            skip_over_next(slice, &mut pos, |ch| ch.is_ascii_punctuation());
+        }
+
+        // TODO: don't include newline?
+        skip_over_next(slice, &mut pos, |ch| ch.is_ascii_whitespace());
+    }
+
+    pos
+}
+
+pub fn move_prev_word_start(slice: RopeSlice, mut pos: usize, count: usize) -> usize {
+    for _ in 0..count {
+        if pos == 0 {
+            return pos;
+        }
+
+        let ch = slice.char(pos);
+        let prev = slice.char(pos - 1);
+
+        if categorize(ch) != categorize(prev) {
+            pos -= 1;
+        }
+
+        // match (category c1, category c2) => {
+        //  if c1 != c2 {
+        //  }
+        // }
+
+        // TODO: skip while eol
+
+        // TODO: don't include newline?
+        skip_over_prev(slice, &mut pos, |ch| ch.is_ascii_whitespace());
+
+        // refetch
+        let ch = slice.char(pos);
+
+        if is_word(ch) {
+            skip_over_prev(slice, &mut pos, is_word);
+        } else if ch.is_ascii_punctuation() {
+            skip_over_prev(slice, &mut pos, |ch| ch.is_ascii_punctuation());
+        }
+        pos = pos.saturating_add(1)
+    }
+
+    pos
+}
+
+pub fn move_next_word_end(slice: RopeSlice, mut pos: usize, count: usize) -> usize {
+    for _ in 0..count {
+        if pos + 1 == slice.len_chars() {
+            return pos;
+        }
+
+        let ch = slice.char(pos);
+        let next = slice.char(pos + 1);
+
+        if categorize(ch) != categorize(next) {
+            pos += 1;
+        }
+
+        // TODO: don't include newline?
+        skip_over_next(slice, &mut pos, |ch| ch.is_ascii_whitespace());
+
+        // refetch
+        let ch = slice.char(pos);
+
+        if is_word(ch) {
+            skip_over_next(slice, &mut pos, is_word);
+        } else if ch.is_ascii_punctuation() {
+            skip_over_next(slice, &mut pos, |ch| ch.is_ascii_punctuation());
+        }
+        pos -= 1
+    }
+
+    pos
+}
+
+// ---- util ------------
+
+// used for by-word movement
+
+fn is_word(ch: char) -> bool {
+    ch.is_alphanumeric() || ch == '_'
+}
+
+#[derive(Debug, Eq, PartialEq)]
+enum Category {
+    Whitespace,
+    Eol,
+    Word,
+    Punctuation,
+}
+fn categorize(ch: char) -> Category {
+    if ch == '\n' {
+        Category::Eol
+    } else if ch.is_ascii_whitespace() {
+        Category::Whitespace
+    } else if ch.is_ascii_punctuation() {
+        Category::Punctuation
+    } else if ch.is_ascii_alphanumeric() {
+        Category::Word
+    } else {
+        unreachable!()
+    }
+}
+
+#[inline]
+pub fn skip_over_next<F>(slice: RopeSlice, pos: &mut usize, fun: F)
+where
+    F: Fn(char) -> bool,
+{
+    let mut chars = slice.chars_at(*pos);
+
+    for ch in chars {
+        if !fun(ch) {
+            break;
+        }
+        *pos += 1;
+    }
+}
+
+#[inline]
+pub fn skip_over_prev<F>(slice: RopeSlice, pos: &mut usize, fun: F)
+where
+    F: Fn(char) -> bool,
+{
+    // need to +1 so that prev() includes current char
+    let mut chars = slice.chars_at(*pos + 1);
+
+    while let Some(ch) = chars.prev() {
+        if !fun(ch) {
+            break;
+        }
+        *pos = pos.saturating_sub(1);
+    }
+}
diff --git a/helix-core/src/position.rs b/helix-core/src/position.rs
index 5e5f902b..346779b0 100644
--- a/helix-core/src/position.rs
+++ b/helix-core/src/position.rs
@@ -1,3 +1,8 @@
+use crate::{
+    graphemes::{nth_next_grapheme_boundary, RopeGraphemes},
+    Rope, RopeSlice,
+};
+
 /// Represents a single point in a text buffer. Zero indexed.
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 pub struct Position {
@@ -44,6 +49,21 @@ impl From<Position> for tree_sitter::Point {
         Self::new(pos.row, pos.col)
     }
 }
+/// Convert a character index to (line, column) coordinates.
+pub fn coords_at_pos(text: RopeSlice, pos: usize) -> Position {
+    let line = text.char_to_line(pos);
+    let line_start = text.line_to_char(line);
+    let col = RopeGraphemes::new(text.slice(line_start..pos)).count();
+    Position::new(line, col)
+}
+
+/// Convert (line, column) coordinates to a character index.
+pub fn pos_at_coords(text: RopeSlice, coords: Position) -> usize {
+    let Position { row, col } = coords;
+    let line_start = text.line_to_char(row);
+    // line_start + col
+    nth_next_grapheme_boundary(text, line_start, col)
+}
 
 #[cfg(test)]
 mod test {
@@ -54,4 +74,58 @@ mod test {
         // (0, 5) is less than (1, 0)
         assert!(Position::new(0, 5) < Position::new(1, 0));
     }
+
+    #[test]
+    fn test_coords_at_pos() {
+        let text = Rope::from("ḧëḷḷö\nẅöṛḷḋ");
+        let slice = text.slice(..);
+        // assert_eq!(coords_at_pos(slice, 0), (0, 0).into());
+        // assert_eq!(coords_at_pos(slice, 5), (0, 5).into()); // position on \n
+        // assert_eq!(coords_at_pos(slice, 6), (1, 0).into()); // position on w
+        // assert_eq!(coords_at_pos(slice, 7), (1, 1).into()); // position on o
+        // assert_eq!(coords_at_pos(slice, 10), (1, 4).into()); // position on d
+
+        // test with grapheme clusters
+        let text = Rope::from("a̐éö̲\r\n");
+        let slice = text.slice(..);
+        assert_eq!(coords_at_pos(slice, 0), (0, 0).into());
+        assert_eq!(coords_at_pos(slice, 2), (0, 1).into());
+        assert_eq!(coords_at_pos(slice, 4), (0, 2).into());
+        assert_eq!(coords_at_pos(slice, 7), (0, 3).into());
+
+        let text = Rope::from("किमपि");
+        let slice = text.slice(..);
+        assert_eq!(coords_at_pos(slice, 0), (0, 0).into());
+        assert_eq!(coords_at_pos(slice, 2), (0, 1).into());
+        assert_eq!(coords_at_pos(slice, 3), (0, 2).into());
+        assert_eq!(coords_at_pos(slice, 5), (0, 3).into());
+    }
+
+    #[test]
+    fn test_pos_at_coords() {
+        let text = Rope::from("ḧëḷḷö\nẅöṛḷḋ");
+        let slice = text.slice(..);
+        assert_eq!(pos_at_coords(slice, (0, 0).into()), 0);
+        assert_eq!(pos_at_coords(slice, (0, 5).into()), 5); // position on \n
+        assert_eq!(pos_at_coords(slice, (1, 0).into()), 6); // position on w
+        assert_eq!(pos_at_coords(slice, (1, 1).into()), 7); // position on o
+        assert_eq!(pos_at_coords(slice, (1, 4).into()), 10); // position on d
+
+        // test with grapheme clusters
+        let text = Rope::from("a̐éö̲\r\n");
+        let slice = text.slice(..);
+        assert_eq!(pos_at_coords(slice, (0, 0).into()), 0);
+        assert_eq!(pos_at_coords(slice, (0, 1).into()), 2);
+        assert_eq!(pos_at_coords(slice, (0, 2).into()), 4);
+        assert_eq!(pos_at_coords(slice, (0, 3).into()), 7); // \r\n is one char here
+        assert_eq!(pos_at_coords(slice, (0, 4).into()), 9);
+        let text = Rope::from("किमपि");
+        // 2 - 1 - 2 codepoints
+        // TODO: delete handling as per https://news.ycombinator.com/item?id=20058454
+        let slice = text.slice(..);
+        assert_eq!(pos_at_coords(slice, (0, 0).into()), 0);
+        assert_eq!(pos_at_coords(slice, (0, 1).into()), 2);
+        assert_eq!(pos_at_coords(slice, (0, 2).into()), 3);
+        assert_eq!(pos_at_coords(slice, (0, 3).into()), 5); // eol
+    }
 }
diff --git a/helix-core/src/state.rs b/helix-core/src/state.rs
index 4d4df489..9dcd5548 100644
--- a/helix-core/src/state.rs
+++ b/helix-core/src/state.rs
@@ -1,7 +1,5 @@
 use crate::graphemes::{nth_next_grapheme_boundary, nth_prev_grapheme_boundary, RopeGraphemes};
-use crate::syntax::LOADER;
-use crate::{ChangeSet, Diagnostic, Position, Range, Rope, RopeSlice, Selection, Syntax};
-use anyhow::Error;
+use crate::{coords_at_pos, pos_at_coords, ChangeSet, Position, Range, Rope, RopeSlice, Selection};
 
 /// A state represents the current editor state of a single buffer.
 #[derive(Clone)]
@@ -83,96 +81,6 @@ impl State {
         Range::new(if extend { range.anchor } else { pos }, pos)
     }
 
-    pub fn move_next_word_start(slice: RopeSlice, mut pos: usize, count: usize) -> usize {
-        for _ in 0..count {
-            if pos + 1 == slice.len_chars() {
-                return pos;
-            }
-
-            let mut ch = slice.char(pos);
-            let next = slice.char(pos + 1);
-
-            // if we're at the end of a word, or on whitespce right before new one
-            if categorize(ch) != categorize(next) {
-                pos += 1;
-                ch = next;
-            }
-
-            if is_word(ch) {
-                skip_over_next(slice, &mut pos, is_word);
-            } else if ch.is_ascii_punctuation() {
-                skip_over_next(slice, &mut pos, |ch| ch.is_ascii_punctuation());
-            }
-
-            // TODO: don't include newline?
-            skip_over_next(slice, &mut pos, |ch| ch.is_ascii_whitespace());
-        }
-
-        pos
-    }
-
-    pub fn move_prev_word_start(slice: RopeSlice, mut pos: usize, count: usize) -> usize {
-        for _ in 0..count {
-            if pos == 0 {
-                return pos;
-            }
-
-            let ch = slice.char(pos);
-            let prev = slice.char(pos - 1);
-
-            if categorize(ch) != categorize(prev) {
-                pos -= 1;
-            }
-
-            // TODO: skip while eol
-
-            // TODO: don't include newline?
-            skip_over_prev(slice, &mut pos, |ch| ch.is_ascii_whitespace());
-
-            // refetch
-            let ch = slice.char(pos);
-
-            if is_word(ch) {
-                skip_over_prev(slice, &mut pos, is_word);
-            } else if ch.is_ascii_punctuation() {
-                skip_over_prev(slice, &mut pos, |ch| ch.is_ascii_punctuation());
-            }
-            pos = pos.saturating_add(1)
-        }
-
-        pos
-    }
-
-    pub fn move_next_word_end(slice: RopeSlice, mut pos: usize, count: usize) -> usize {
-        for _ in 0..count {
-            if pos + 1 == slice.len_chars() {
-                return pos;
-            }
-
-            let ch = slice.char(pos);
-            let next = slice.char(pos + 1);
-
-            if categorize(ch) != categorize(next) {
-                pos += 1;
-            }
-
-            // TODO: don't include newline?
-            skip_over_next(slice, &mut pos, |ch| ch.is_ascii_whitespace());
-
-            // refetch
-            let ch = slice.char(pos);
-
-            if is_word(ch) {
-                skip_over_next(slice, &mut pos, is_word);
-            } else if ch.is_ascii_punctuation() {
-                skip_over_next(slice, &mut pos, |ch| ch.is_ascii_punctuation());
-            }
-            pos -= 1
-        }
-
-        pos
-    }
-
     pub fn move_selection(
         &self,
         dir: Direction,
@@ -194,22 +102,6 @@ impl State {
     }
 }
 
-/// Convert a character index to (line, column) coordinates.
-pub fn coords_at_pos(text: RopeSlice, pos: usize) -> Position {
-    let line = text.char_to_line(pos);
-    let line_start = text.line_to_char(line);
-    let col = RopeGraphemes::new(text.slice(line_start..pos)).count();
-    Position::new(line, col)
-}
-
-/// Convert (line, column) coordinates to a character index.
-pub fn pos_at_coords(text: RopeSlice, coords: Position) -> usize {
-    let Position { row, col } = coords;
-    let line_start = text.line_to_char(row);
-    // line_start + col
-    nth_next_grapheme_boundary(text, line_start, col)
-}
-
 fn move_vertically(
     text: RopeSlice,
     dir: Direction,
@@ -238,123 +130,11 @@ fn move_vertically(
     range
 }
 
-// used for by-word movement
-
-fn is_word(ch: char) -> bool {
-    ch.is_alphanumeric() || ch == '_'
-}
-
-#[derive(Debug, Eq, PartialEq)]
-enum Category {
-    Whitespace,
-    Eol,
-    Word,
-    Punctuation,
-}
-fn categorize(ch: char) -> Category {
-    if ch == '\n' {
-        Category::Eol
-    } else if ch.is_ascii_whitespace() {
-        Category::Whitespace
-    } else if ch.is_ascii_punctuation() {
-        Category::Punctuation
-    } else if ch.is_ascii_alphanumeric() {
-        Category::Word
-    } else {
-        unreachable!()
-    }
-}
-
-#[inline]
-pub fn skip_over_next<F>(slice: RopeSlice, pos: &mut usize, fun: F)
-where
-    F: Fn(char) -> bool,
-{
-    let mut chars = slice.chars_at(*pos);
-
-    for ch in chars {
-        if !fun(ch) {
-            break;
-        }
-        *pos += 1;
-    }
-}
-
-#[inline]
-pub fn skip_over_prev<F>(slice: RopeSlice, pos: &mut usize, fun: F)
-where
-    F: Fn(char) -> bool,
-{
-    // need to +1 so that prev() includes current char
-    let mut chars = slice.chars_at(*pos + 1);
-
-    while let Some(ch) = chars.prev() {
-        if !fun(ch) {
-            break;
-        }
-        *pos = pos.saturating_sub(1);
-    }
-}
-
 #[cfg(test)]
 mod test {
     use super::*;
 
     #[test]
-    fn test_coords_at_pos() {
-        let text = Rope::from("ḧëḷḷö\nẅöṛḷḋ");
-        let slice = text.slice(..);
-        // assert_eq!(coords_at_pos(slice, 0), (0, 0).into());
-        // assert_eq!(coords_at_pos(slice, 5), (0, 5).into()); // position on \n
-        // assert_eq!(coords_at_pos(slice, 6), (1, 0).into()); // position on w
-        // assert_eq!(coords_at_pos(slice, 7), (1, 1).into()); // position on o
-        // assert_eq!(coords_at_pos(slice, 10), (1, 4).into()); // position on d
-
-        // test with grapheme clusters
-        let text = Rope::from("a̐éö̲\r\n");
-        let slice = text.slice(..);
-        assert_eq!(coords_at_pos(slice, 0), (0, 0).into());
-        assert_eq!(coords_at_pos(slice, 2), (0, 1).into());
-        assert_eq!(coords_at_pos(slice, 4), (0, 2).into());
-        assert_eq!(coords_at_pos(slice, 7), (0, 3).into());
-
-        let text = Rope::from("किमपि");
-        let slice = text.slice(..);
-        assert_eq!(coords_at_pos(slice, 0), (0, 0).into());
-        assert_eq!(coords_at_pos(slice, 2), (0, 1).into());
-        assert_eq!(coords_at_pos(slice, 3), (0, 2).into());
-        assert_eq!(coords_at_pos(slice, 5), (0, 3).into());
-    }
-
-    #[test]
-    fn test_pos_at_coords() {
-        let text = Rope::from("ḧëḷḷö\nẅöṛḷḋ");
-        let slice = text.slice(..);
-        assert_eq!(pos_at_coords(slice, (0, 0).into()), 0);
-        assert_eq!(pos_at_coords(slice, (0, 5).into()), 5); // position on \n
-        assert_eq!(pos_at_coords(slice, (1, 0).into()), 6); // position on w
-        assert_eq!(pos_at_coords(slice, (1, 1).into()), 7); // position on o
-        assert_eq!(pos_at_coords(slice, (1, 4).into()), 10); // position on d
-
-        // test with grapheme clusters
-        let text = Rope::from("a̐éö̲\r\n");
-        let slice = text.slice(..);
-        assert_eq!(pos_at_coords(slice, (0, 0).into()), 0);
-        assert_eq!(pos_at_coords(slice, (0, 1).into()), 2);
-        assert_eq!(pos_at_coords(slice, (0, 2).into()), 4);
-        assert_eq!(pos_at_coords(slice, (0, 3).into()), 7); // \r\n is one char here
-        assert_eq!(pos_at_coords(slice, (0, 4).into()), 9);
-        let text = Rope::from("किमपि");
-        // 2 - 1 - 2 codepoints
-        // TODO: delete handling as per https://news.ycombinator.com/item?id=20058454
-        let slice = text.slice(..);
-        assert_eq!(pos_at_coords(slice, (0, 0).into()), 0);
-        assert_eq!(pos_at_coords(slice, (0, 1).into()), 2);
-        assert_eq!(pos_at_coords(slice, (0, 2).into()), 3);
-        assert_eq!(pos_at_coords(slice, (0, 3).into()), 5); // eol
-    }
-
-    #[test]
     fn test_vertical_move() {
         let text = Rope::from("abcd\nefg\nwrs");
         let slice = text.slice(..);
diff --git a/helix-core/src/syntax.rs b/helix-core/src/syntax.rs
index 3d665953..e75dc724 100644
--- a/helix-core/src/syntax.rs
+++ b/helix-core/src/syntax.rs
@@ -355,7 +355,7 @@ pub struct LanguageLayer {
     pub(crate) tree: Option<Tree>,
 }
 
-use crate::state::coords_at_pos;
+use crate::coords_at_pos;
 use crate::transaction::{ChangeSet, Operation};
 use crate::Tendril;