Add a command module.

helix-core/src/commands.rs

@@ -0,0 +1,45 @@
+use crate::state::{Direction, Granularity, State};
+
+/// A command is a function that takes the current state and a count, and does a side-effect on the
+/// state (usually by creating and applying a transaction).
+type Command = fn(state: &mut State, count: usize);
+
+fn move_char_left(state: &mut State, count: usize) {
+    // TODO: use a transaction
+    state.selection = state.move_selection(
+        state.selection,
+        Direction::Backward,
+        Granularity::Character,
+        count,
+    );
+}
+
+fn move_char_right(state: &mut State, count: usize) {
+    // TODO: use a transaction
+    state.selection = state.move_selection(
+        state.selection,
+        Direction::Forward,
+        Granularity::Character,
+        count,
+    );
+}
+
+fn move_line_up(state: &mut State, count: usize) {
+    // TODO: use a transaction
+    state.selection = state.move_selection(
+        state.selection,
+        Direction::Backward,
+        Granularity::Line,
+        count,
+    );
+}
+
+fn move_line_down(state: &mut State, count: usize) {
+    // TODO: use a transaction
+    state.selection = state.move_selection(
+        state.selection,
+        Direction::Forward,
+        Granularity::Line,
+        count,
+    );
+}

helix-core/src/lib.rs

@@ -1,5 +1,6 @@
 #![allow(unused)]
 mod buffer;
+pub mod commands;
 mod graphemes;
 mod selection;
 mod state;

helix-core/src/state.rs

@@ -3,8 +3,8 @@
 
 /// A state represents the current editor state of a single buffer.
 pub struct State {
-    doc: Buffer,
+    pub(crate) doc: Buffer,
-    selection: Selection,
+    pub(crate) selection: Selection,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq)]
@@ -59,17 +59,17 @@ pub fn move_pos(
         pos: usize,
         dir: Direction,
         granularity: Granularity,
-        n: usize,
+        count: usize,
     ) -> usize {
         let text = &self.doc.contents;
         match (dir, granularity) {
             (Direction::Backward, Granularity::Character) => {
-                nth_prev_grapheme_boundary(&text.slice(..), pos, n)
+                nth_prev_grapheme_boundary(&text.slice(..), pos, count)
             }
             (Direction::Forward, Granularity::Character) => {
-                nth_next_grapheme_boundary(&text.slice(..), pos, n)
+                nth_next_grapheme_boundary(&text.slice(..), pos, count)
             }
-            (_, Granularity::Line) => move_vertically(&text.slice(..), dir, pos, n),
+            (_, Granularity::Line) => move_vertically(&text.slice(..), dir, pos, count),
             _ => pos,
         }
     }
@@ -79,7 +79,7 @@ pub fn move_selection(
         sel: Selection,
         dir: Direction,
         granularity: Granularity,
-        // TODO: n
+        count: usize,
     ) -> Selection {
         // TODO: move all selections according to normal cursor move semantics by collapsing it
         // into cursors and moving them vertically
@@ -93,7 +93,7 @@ pub fn move_selection(
             //         range.to()
             //     }
             // } else {
-            let pos = self.move_pos(range.head, dir, granularity, 1);
+            let pos = self.move_pos(range.head, dir, granularity, count);
             // };
             SelectionRange::new(pos, pos)
         });
@@ -107,10 +107,10 @@ pub fn extend_selection(
         sel: Selection,
         dir: Direction,
         granularity: Granularity,
-        n: usize,
+        count: usize,
     ) -> Selection {
         let ranges = sel.ranges.into_iter().map(|range| {
-            let pos = self.move_pos(range.head, dir, granularity, n);
+            let pos = self.move_pos(range.head, dir, granularity, count);
             SelectionRange::new(range.anchor, pos)
         });
 
@@ -138,7 +138,7 @@ pub fn pos_at_coords(text: &RopeSlice, coords: Coords) -> usize {
     nth_next_grapheme_boundary(text, line_start, col)
 }
 
-fn move_vertically(text: &RopeSlice, dir: Direction, pos: usize, n: usize) -> usize {
+fn move_vertically(text: &RopeSlice, dir: Direction, pos: usize, count: usize) -> usize {
     let (line, col) = coords_at_pos(text, pos);
 
     let new_line = match dir {
@@ -159,10 +159,6 @@ fn move_vertically(text: &RopeSlice, dir: Direction, pos: usize, n: usize) -> us
     pos_at_coords(text, (new_line, new_col))
 }
 
-/// A command is a function that takes the current state and a count, and does a side-effect on the
-/// state (usually by creating and applying a transaction).
-type Command = fn(state: &mut State, count: usize) -> bool;
-
 #[cfg(test)]
 mod test {
     use super::*;