use crate::{ chars::char_is_line_ending, graphemes::{ensure_grapheme_boundary_prev, RopeGraphemes}, line_ending::line_end_char_index, 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 let mut chars = text.chars().peekable(); while let Some(ch) = chars.next() { if char_is_line_ending(ch) && !(ch == '\r' && chars.peek() == Some(&'\n')) { row += 1; col = 0; } else { col += 1; } } Self { row, col } } } impl From<(usize, usize)> for Position { fn from(tuple: (usize, usize)) -> Self { Self { 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. /// /// TODO: this should be split into two methods: one for visual /// row/column, and one for "objective" row/column (possibly with /// the column specified in `char`s). The former would be used /// for cursor movement, and the latter would be used for e.g. the /// row:column display in the status line. 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 pos = ensure_grapheme_boundary_prev(text, pos); let col = RopeGraphemes::new(text.slice(line_start..pos)).count(); Position::new(line, col) } /// Convert (line, column) coordinates to a character index. /// /// `is_1_width` specifies whether the position should be treated /// as a block cursor or not. This effects how line-ends are handled. /// `false` corresponds to properly round-tripping with `coords_at_pos()`, /// whereas `true` will ensure that block cursors don't jump off the /// end of the line. /// /// TODO: this should be changed to work in terms of visual row/column, not /// graphemes. pub fn pos_at_coords(text: RopeSlice, coords: Position, is_1_width: bool) -> usize { let Position { row, col } = coords; let line_start = text.line_to_char(row); let line_end = if is_1_width { line_end_char_index(&text, row) } else { text.line_to_char((row + 1).min(text.len_lines())) }; let mut col_char_offset = 0; for (i, g) in RopeGraphemes::new(text.slice(line_start..line_end)).enumerate() { if i == col { break; } col_char_offset += g.chars().count(); } line_start + col_char_offset } #[cfg(test)] mod test { use super::*; use crate::Rope; #[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 wide characters. // TODO: account for character width. let text = Rope::from("今日はいい\n"); let slice = text.slice(..); assert_eq!(coords_at_pos(slice, 0), (0, 0).into()); assert_eq!(coords_at_pos(slice, 1), (0, 1).into()); assert_eq!(coords_at_pos(slice, 2), (0, 2).into()); assert_eq!(coords_at_pos(slice, 3), (0, 3).into()); assert_eq!(coords_at_pos(slice, 4), (0, 4).into()); assert_eq!(coords_at_pos(slice, 5), (0, 5).into()); assert_eq!(coords_at_pos(slice, 6), (1, 0).into()); // 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()); assert_eq!(coords_at_pos(slice, 9), (1, 0).into()); // Test with wide-character grapheme clusters. // TODO: account for character width. let text = Rope::from("किमपि\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, 3), (0, 2).into()); assert_eq!(coords_at_pos(slice, 5), (0, 3).into()); assert_eq!(coords_at_pos(slice, 6), (1, 0).into()); // Test with tabs. // Todo: account for tab stops. let text = Rope::from("\tHello\n"); let slice = text.slice(..); assert_eq!(coords_at_pos(slice, 0), (0, 0).into()); assert_eq!(coords_at_pos(slice, 1), (0, 1).into()); assert_eq!(coords_at_pos(slice, 2), (0, 2).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(), false), 0); assert_eq!(pos_at_coords(slice, (0, 5).into(), false), 5); // position on \n assert_eq!(pos_at_coords(slice, (0, 6).into(), false), 6); // position after \n assert_eq!(pos_at_coords(slice, (0, 6).into(), true), 5); // position after \n assert_eq!(pos_at_coords(slice, (1, 0).into(), false), 6); // position on w assert_eq!(pos_at_coords(slice, (1, 1).into(), false), 7); // position on o assert_eq!(pos_at_coords(slice, (1, 4).into(), false), 10); // position on d // Test with wide characters. // TODO: account for character width. let text = Rope::from("今日はいい\n"); let slice = text.slice(..); assert_eq!(pos_at_coords(slice, (0, 0).into(), false), 0); assert_eq!(pos_at_coords(slice, (0, 1).into(), false), 1); assert_eq!(pos_at_coords(slice, (0, 2).into(), false), 2); assert_eq!(pos_at_coords(slice, (0, 3).into(), false), 3); assert_eq!(pos_at_coords(slice, (0, 4).into(), false), 4); assert_eq!(pos_at_coords(slice, (0, 5).into(), false), 5); assert_eq!(pos_at_coords(slice, (0, 6).into(), false), 6); assert_eq!(pos_at_coords(slice, (0, 6).into(), true), 5); assert_eq!(pos_at_coords(slice, (1, 0).into(), false), 6); // Test with grapheme clusters. let text = Rope::from("a̐éö̲\r\n"); let slice = text.slice(..); assert_eq!(pos_at_coords(slice, (0, 0).into(), false), 0); assert_eq!(pos_at_coords(slice, (0, 1).into(), false), 2); assert_eq!(pos_at_coords(slice, (0, 2).into(), false), 4); assert_eq!(pos_at_coords(slice, (0, 3).into(), false), 7); // \r\n is one char here assert_eq!(pos_at_coords(slice, (0, 4).into(), false), 9); assert_eq!(pos_at_coords(slice, (0, 4).into(), true), 7); assert_eq!(pos_at_coords(slice, (1, 0).into(), false), 9); // Test with wide-character grapheme clusters. // TODO: account for character width. 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(), false), 0); assert_eq!(pos_at_coords(slice, (0, 1).into(), false), 2); assert_eq!(pos_at_coords(slice, (0, 2).into(), false), 3); assert_eq!(pos_at_coords(slice, (0, 3).into(), false), 5); assert_eq!(pos_at_coords(slice, (0, 3).into(), true), 5); // Test with tabs. // Todo: account for tab stops. let text = Rope::from("\tHello\n"); let slice = text.slice(..); assert_eq!(pos_at_coords(slice, (0, 0).into(), false), 0); assert_eq!(pos_at_coords(slice, (0, 1).into(), false), 1); assert_eq!(pos_at_coords(slice, (0, 2).into(), false), 2); } }