use std::borrow::Cow; use crate::{ chars::char_is_line_ending, graphemes::{ensure_grapheme_boundary_prev, grapheme_width, 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. /// /// column in `char` count which can be used for row:column display in /// status line. See [`visual_coords_at_pos`] for a visual one. 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 a character index to (line, column) coordinates visually. /// /// Takes \t, double-width characters (CJK) into account as well as text /// not in the document in the future. /// See [`coords_at_pos`] for an "objective" one. pub fn visual_coords_at_pos(text: RopeSlice, pos: usize, tab_width: 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 mut col = 0; for grapheme in RopeGraphemes::new(text.slice(line_start..pos)) { if grapheme == "\t" { col += tab_width - (col % tab_width); } else { let grapheme = Cow::from(grapheme); col += grapheme_width(&grapheme); } } Position::new(line, col) } /// Convert (line, column) coordinates to a character index. /// /// If the `line` coordinate is beyond the end of the file, the EOF /// position will be returned. /// /// If the `column` coordinate is past the end of the given line, the /// line-end position will be returned. What constitutes the "line-end /// position" depends on the parameter `limit_before_line_ending`. If it's /// `true`, the line-end position will be just *before* the line ending /// character. If `false` it will be just *after* the line ending /// character--on the border between the current line and the next. /// /// Usually you only want `limit_before_line_ending` to be `true` if you're working /// with left-side block-cursor positions, as this prevents the the block cursor /// from jumping to the next line. Otherwise you typically want it to be `false`, /// such as when dealing with raw anchor/head positions. /// /// TODO: this should be changed to work in terms of visual row/column, not /// graphemes. pub fn pos_at_coords(text: RopeSlice, coords: Position, limit_before_line_ending: bool) -> usize { let Position { mut row, col } = coords; if limit_before_line_ending { row = row.min(text.len_lines() - 1); }; let line_start = text.line_to_char(row); let line_end = if limit_before_line_ending { 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. 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. 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. 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_visual_coords_at_pos() { let text = Rope::from("ḧëḷḷö\nẅöṛḷḋ"); let slice = text.slice(..); assert_eq!(visual_coords_at_pos(slice, 0, 8), (0, 0).into()); assert_eq!(visual_coords_at_pos(slice, 5, 8), (0, 5).into()); // position on \n assert_eq!(visual_coords_at_pos(slice, 6, 8), (1, 0).into()); // position on w assert_eq!(visual_coords_at_pos(slice, 7, 8), (1, 1).into()); // position on o assert_eq!(visual_coords_at_pos(slice, 10, 8), (1, 4).into()); // position on d // Test with wide characters. let text = Rope::from("今日はいい\n"); let slice = text.slice(..); assert_eq!(visual_coords_at_pos(slice, 0, 8), (0, 0).into()); assert_eq!(visual_coords_at_pos(slice, 1, 8), (0, 2).into()); assert_eq!(visual_coords_at_pos(slice, 2, 8), (0, 4).into()); assert_eq!(visual_coords_at_pos(slice, 3, 8), (0, 6).into()); assert_eq!(visual_coords_at_pos(slice, 4, 8), (0, 8).into()); assert_eq!(visual_coords_at_pos(slice, 5, 8), (0, 10).into()); assert_eq!(visual_coords_at_pos(slice, 6, 8), (1, 0).into()); // Test with grapheme clusters. let text = Rope::from("a̐éö̲\r\n"); let slice = text.slice(..); assert_eq!(visual_coords_at_pos(slice, 0, 8), (0, 0).into()); assert_eq!(visual_coords_at_pos(slice, 2, 8), (0, 1).into()); assert_eq!(visual_coords_at_pos(slice, 4, 8), (0, 2).into()); assert_eq!(visual_coords_at_pos(slice, 7, 8), (0, 3).into()); assert_eq!(visual_coords_at_pos(slice, 9, 8), (1, 0).into()); // Test with wide-character grapheme clusters. // TODO: account for cluster. let text = Rope::from("किमपि\n"); let slice = text.slice(..); assert_eq!(visual_coords_at_pos(slice, 0, 8), (0, 0).into()); assert_eq!(visual_coords_at_pos(slice, 2, 8), (0, 2).into()); assert_eq!(visual_coords_at_pos(slice, 3, 8), (0, 3).into()); assert_eq!(visual_coords_at_pos(slice, 5, 8), (0, 5).into()); assert_eq!(visual_coords_at_pos(slice, 6, 8), (1, 0).into()); // Test with tabs. let text = Rope::from("\tHello\n"); let slice = text.slice(..); assert_eq!(visual_coords_at_pos(slice, 0, 8), (0, 0).into()); assert_eq!(visual_coords_at_pos(slice, 1, 8), (0, 8).into()); assert_eq!(visual_coords_at_pos(slice, 2, 8), (0, 9).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); // Test out of bounds. let text = Rope::new(); let slice = text.slice(..); assert_eq!(pos_at_coords(slice, (10, 0).into(), true), 0); assert_eq!(pos_at_coords(slice, (0, 10).into(), true), 0); assert_eq!(pos_at_coords(slice, (10, 10).into(), true), 0); } }