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 { pub row: usize, pub col: usize, } impl Position { pub const fn new(row: usize, col: usize) -> Self { Self { row, col } } pub const fn is_zero(self) -> bool { self.row == 0 && self.col == 0 } // TODO: generalize pub fn traverse(self, text: &crate::Tendril) -> Self { let Self { mut row, mut col } = self; // TODO: there should be a better way here for ch in text.chars() { if ch == '\n' { row += 1; col = 0; } else { col += 1; } } Self { row, col } } } impl From<(usize, usize)> for Position { fn from(tuple: (usize, usize)) -> Self { Position { row: tuple.0, col: tuple.1, } } } impl From for tree_sitter::Point { fn from(pos: Position) -> Self { 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 { use super::*; #[test] fn test_ordering() { // (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 } }