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-rw-r--r--helix-core/src/state.rs45
1 files changed, 42 insertions, 3 deletions
diff --git a/helix-core/src/state.rs b/helix-core/src/state.rs
index ccbfd28a..5379fa7d 100644
--- a/helix-core/src/state.rs
+++ b/helix-core/src/state.rs
@@ -69,6 +69,7 @@ impl State {
(Direction::Forward, Granularity::Character) => {
nth_next_grapheme_boundary(&text.slice(..), pos, n)
}
+ (_, Granularity::Line) => move_vertically(&text.slice(..), dir, pos, n),
_ => pos,
}
}
@@ -125,7 +126,8 @@ type Coords = (usize, usize); // line, col
pub fn coords_at_pos(text: &RopeSlice, pos: usize) -> Coords {
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();
+ // convert to 0-indexed
+ let col = text.slice(line_start..pos).len_chars().saturating_sub(1);
(line, col)
}
@@ -136,6 +138,31 @@ 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 {
+ let (line, col) = coords_at_pos(text, pos);
+
+ let new_line = match dir {
+ Direction::Backward => line.saturating_sub(n),
+ Direction::Forward => std::cmp::min(line.saturating_add(n), text.len_lines() - 1),
+ };
+
+ // convert to 0-indexed
+ let new_line_len = text.line(new_line).len_chars().saturating_sub(1);
+
+ let new_col = if new_line_len < col {
+ // TODO: preserve horiz here
+ new_line_len
+ } else {
+ col
+ };
+
+ 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::*;
@@ -144,9 +171,9 @@ mod test {
fn test_coords_at_pos() {
let text = Rope::from("ḧëḷḷö\nẅöṛḷḋ");
assert_eq!(coords_at_pos(&text.slice(..), 0), (0, 0));
- assert_eq!(coords_at_pos(&text.slice(..), 5), (0, 5)); // position on \n
+ assert_eq!(coords_at_pos(&text.slice(..), 5), (0, 4)); // position on \n
assert_eq!(coords_at_pos(&text.slice(..), 6), (1, 0)); // position on w
- assert_eq!(coords_at_pos(&text.slice(..), 11), (1, 5)); // position on d
+ assert_eq!(coords_at_pos(&text.slice(..), 11), (1, 4)); // position on d
}
#[test]
@@ -157,4 +184,16 @@ mod test {
assert_eq!(pos_at_coords(&text.slice(..), (1, 0)), 6); // position on w
assert_eq!(pos_at_coords(&text.slice(..), (1, 5)), 11); // position on d
}
+
+ #[test]
+ fn test_vertical_move() {
+ let text = Rope::from("abcd\nefg\nwrs");
+ let pos = pos_at_coords(&text.slice(..), (0, 4));
+ let slice = text.slice(..);
+
+ assert_eq!(
+ coords_at_pos(&slice, move_vertically(&slice, Direction::Forward, pos, 1)),
+ (1, 2)
+ );
+ }
}