Fix coord mapping, add vertical move.

pull/1/head
Blaž Hrastnik 4 years ago
parent 10d53f3ef0
commit 195aad4675

@ -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)
);
}
}

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