diff --git a/helix-core/src/graphemes.rs b/helix-core/src/graphemes.rs index f7bf66c0b..0465fe510 100644 --- a/helix-core/src/graphemes.rs +++ b/helix-core/src/graphemes.rs @@ -71,6 +71,8 @@ pub fn nth_prev_grapheme_boundary(slice: RopeSlice, char_idx: usize, n: usize) - } /// Finds the previous grapheme boundary before the given char position. +#[must_use] +#[inline(always)] pub fn prev_grapheme_boundary(slice: RopeSlice, char_idx: usize) -> usize { nth_prev_grapheme_boundary(slice, char_idx, 1) } @@ -117,12 +119,16 @@ pub fn nth_next_grapheme_boundary(slice: RopeSlice, char_idx: usize, n: usize) - } /// Finds the next grapheme boundary after the given char position. +#[must_use] +#[inline(always)] pub fn next_grapheme_boundary(slice: RopeSlice, char_idx: usize) -> usize { nth_next_grapheme_boundary(slice, char_idx, 1) } /// Returns the passed char index if it's already a grapheme boundary, /// or the next grapheme boundary char index if not. +#[must_use] +#[inline] pub fn ensure_grapheme_boundary_next(slice: RopeSlice, char_idx: usize) -> usize { if char_idx == 0 { char_idx @@ -133,6 +139,8 @@ pub fn ensure_grapheme_boundary_next(slice: RopeSlice, char_idx: usize) -> usize /// Returns the passed char index if it's already a grapheme boundary, /// or the prev grapheme boundary char index if not. +#[must_use] +#[inline] pub fn ensure_grapheme_boundary_prev(slice: RopeSlice, char_idx: usize) -> usize { if char_idx == slice.len_chars() { char_idx @@ -142,6 +150,7 @@ pub fn ensure_grapheme_boundary_prev(slice: RopeSlice, char_idx: usize) -> usize } /// Returns whether the given char position is a grapheme boundary. +#[must_use] pub fn is_grapheme_boundary(slice: RopeSlice, char_idx: usize) -> bool { // Bounds check debug_assert!(char_idx <= slice.len_chars()); diff --git a/helix-core/src/selection.rs b/helix-core/src/selection.rs index 906e2e53b..4260c002c 100644 --- a/helix-core/src/selection.rs +++ b/helix-core/src/selection.rs @@ -137,58 +137,61 @@ impl Range { } } - /// Compute the ends of the range, shifted (if needed) to align with - /// grapheme boundaries. + /// Compute a possibly new range from this range, attempting to ensure + /// a minimum range width of 1 char by shifting the head in the forward + /// direction as needed. /// - /// This should generally be used for cursor validation. + /// This method will never shift the anchor, and will only shift the + /// head in the forward direction. Therefore, this method can fail + /// at ensuring the minimum width if and only if the passed range is + /// both zero-width and at the end of the `RopeSlice`. /// - /// Always succeeds. + /// If the input range is grapheme-boundary aligned, the returned range + /// will also be. Specifically, if the head needs to shift to achieve + /// the minimum width, it will shift to the next grapheme boundary. #[must_use] - pub fn aligned_range(&self, slice: RopeSlice) -> (usize, usize) { + #[inline] + pub fn min_width_1(&self, slice: RopeSlice) -> Self { if self.anchor == self.head { - let pos = ensure_grapheme_boundary_prev(slice, self.anchor); - (pos, pos) + Range { + anchor: self.anchor, + head: next_grapheme_boundary(slice, self.head), + horiz: self.horiz, + } } else { - ( - ensure_grapheme_boundary_prev(slice, self.from()), - ensure_grapheme_boundary_next(slice, self.to()), - ) + *self } } - /// Same as `ensure_grapheme_validity()` + attempts to ensure a minimum - /// char width in the direction of the head. - /// - /// This should generally be used as a pre-pass for operations that - /// require a minimum selection width to achieve their intended behavior. - /// - /// This will fail at ensuring the minimum width only if the passed - /// `RopeSlice` is too short in the direction of the head, in which - /// case the range will fill the available length in that direction. + /// Compute a possibly new range from this range, with its ends + /// shifted as needed to align with grapheme boundaries. /// - /// Ensuring grapheme-boundary alignment always succeeds. + /// Zero-width ranges will always stay zero-width, and non-zero-width + /// ranges will never collapse to zero-width. #[must_use] - pub fn min_width_range(&self, slice: RopeSlice, min_char_width: usize) -> (usize, usize) { - if min_char_width == 0 { - return self.aligned_range(slice); - } - - if self.anchor <= self.head { - let anchor = ensure_grapheme_boundary_prev(slice, self.anchor); - let head = ensure_grapheme_boundary_next( - slice, - self.head - .max(anchor + min_char_width) - .min(slice.len_chars()), - ); - (anchor, head) + pub fn grapheme_aligned(&self, slice: RopeSlice) -> Self { + let (new_anchor, new_head) = if self.anchor == self.head { + let pos = ensure_grapheme_boundary_prev(slice, self.anchor); + (pos, pos) + } else if self.anchor < self.head { + ( + ensure_grapheme_boundary_prev(slice, self.anchor), + ensure_grapheme_boundary_next(slice, self.head), + ) } else { - let anchor = ensure_grapheme_boundary_next(slice, self.anchor); - let head = ensure_grapheme_boundary_prev( - slice, - self.head.min(anchor.saturating_sub(min_char_width)), - ); - (head, anchor) + ( + ensure_grapheme_boundary_next(slice, self.anchor), + ensure_grapheme_boundary_prev(slice, self.head), + ) + }; + Range { + anchor: new_anchor, + head: new_head, + horiz: if new_anchor == self.anchor { + self.horiz + } else { + None + }, } } @@ -571,97 +574,127 @@ mod test { #[test] fn test_overlaps() { + fn overlaps(a: (usize, usize), b: (usize, usize)) -> bool { + Range::new(a.0, a.1).overlaps(&Range::new(b.0, b.1)) + } + // Two non-zero-width ranges, no overlap. - assert!(!Range::new(0, 3).overlaps(&Range::new(3, 6))); - assert!(!Range::new(0, 3).overlaps(&Range::new(6, 3))); - assert!(!Range::new(3, 0).overlaps(&Range::new(3, 6))); - assert!(!Range::new(3, 0).overlaps(&Range::new(6, 3))); - assert!(!Range::new(3, 6).overlaps(&Range::new(0, 3))); - assert!(!Range::new(3, 6).overlaps(&Range::new(3, 0))); - assert!(!Range::new(6, 3).overlaps(&Range::new(0, 3))); - assert!(!Range::new(6, 3).overlaps(&Range::new(3, 0))); + assert!(!overlaps((0, 3), (3, 6))); + assert!(!overlaps((0, 3), (6, 3))); + assert!(!overlaps((3, 0), (3, 6))); + assert!(!overlaps((3, 0), (6, 3))); + assert!(!overlaps((3, 6), (0, 3))); + assert!(!overlaps((3, 6), (3, 0))); + assert!(!overlaps((6, 3), (0, 3))); + assert!(!overlaps((6, 3), (3, 0))); // Two non-zero-width ranges, overlap. - assert!(Range::new(0, 4).overlaps(&Range::new(3, 6))); - assert!(Range::new(0, 4).overlaps(&Range::new(6, 3))); - assert!(Range::new(4, 0).overlaps(&Range::new(3, 6))); - assert!(Range::new(4, 0).overlaps(&Range::new(6, 3))); - assert!(Range::new(3, 6).overlaps(&Range::new(0, 4))); - assert!(Range::new(3, 6).overlaps(&Range::new(4, 0))); - assert!(Range::new(6, 3).overlaps(&Range::new(0, 4))); - assert!(Range::new(6, 3).overlaps(&Range::new(4, 0))); + assert!(overlaps((0, 4), (3, 6))); + assert!(overlaps((0, 4), (6, 3))); + assert!(overlaps((4, 0), (3, 6))); + assert!(overlaps((4, 0), (6, 3))); + assert!(overlaps((3, 6), (0, 4))); + assert!(overlaps((3, 6), (4, 0))); + assert!(overlaps((6, 3), (0, 4))); + assert!(overlaps((6, 3), (4, 0))); // Zero-width and non-zero-width range, no overlap. - assert!(!Range::new(0, 3).overlaps(&Range::new(3, 3))); - assert!(!Range::new(3, 0).overlaps(&Range::new(3, 3))); - assert!(!Range::new(3, 3).overlaps(&Range::new(0, 3))); - assert!(!Range::new(3, 3).overlaps(&Range::new(3, 0))); + assert!(!overlaps((0, 3), (3, 3))); + assert!(!overlaps((3, 0), (3, 3))); + assert!(!overlaps((3, 3), (0, 3))); + assert!(!overlaps((3, 3), (3, 0))); // Zero-width and non-zero-width range, overlap. - assert!(Range::new(1, 4).overlaps(&Range::new(1, 1))); - assert!(Range::new(4, 1).overlaps(&Range::new(1, 1))); - assert!(Range::new(1, 1).overlaps(&Range::new(1, 4))); - assert!(Range::new(1, 1).overlaps(&Range::new(4, 1))); + assert!(overlaps((1, 4), (1, 1))); + assert!(overlaps((4, 1), (1, 1))); + assert!(overlaps((1, 1), (1, 4))); + assert!(overlaps((1, 1), (4, 1))); - assert!(Range::new(1, 4).overlaps(&Range::new(3, 3))); - assert!(Range::new(4, 1).overlaps(&Range::new(3, 3))); - assert!(Range::new(3, 3).overlaps(&Range::new(1, 4))); - assert!(Range::new(3, 3).overlaps(&Range::new(4, 1))); + assert!(overlaps((1, 4), (3, 3))); + assert!(overlaps((4, 1), (3, 3))); + assert!(overlaps((3, 3), (1, 4))); + assert!(overlaps((3, 3), (4, 1))); // Two zero-width ranges, no overlap. - assert!(!Range::new(0, 0).overlaps(&Range::new(1, 1))); - assert!(!Range::new(1, 1).overlaps(&Range::new(0, 0))); + assert!(!overlaps((0, 0), (1, 1))); + assert!(!overlaps((1, 1), (0, 0))); // Two zero-width ranges, overlap. - assert!(Range::new(1, 1).overlaps(&Range::new(1, 1))); + assert!(overlaps((1, 1), (1, 1))); } #[test] - fn test_aligned_range() { + fn test_graphem_aligned() { let r = Rope::from_str("\r\nHi\r\n"); let s = r.slice(..); - assert_eq!(Range::new(0, 0).aligned_range(s), (0, 0)); - assert_eq!(Range::new(0, 1).aligned_range(s), (0, 2)); - assert_eq!(Range::new(1, 1).aligned_range(s), (0, 0)); - assert_eq!(Range::new(1, 2).aligned_range(s), (0, 2)); - assert_eq!(Range::new(2, 2).aligned_range(s), (2, 2)); - assert_eq!(Range::new(2, 3).aligned_range(s), (2, 3)); - assert_eq!(Range::new(1, 3).aligned_range(s), (0, 3)); - assert_eq!(Range::new(3, 5).aligned_range(s), (3, 6)); - assert_eq!(Range::new(4, 5).aligned_range(s), (4, 6)); - assert_eq!(Range::new(5, 5).aligned_range(s), (4, 4)); - assert_eq!(Range::new(6, 6).aligned_range(s), (6, 6)); + // Zero-width. + assert_eq!(Range::new(0, 0).grapheme_aligned(s), Range::new(0, 0)); + assert_eq!(Range::new(1, 1).grapheme_aligned(s), Range::new(0, 0)); + assert_eq!(Range::new(2, 2).grapheme_aligned(s), Range::new(2, 2)); + assert_eq!(Range::new(3, 3).grapheme_aligned(s), Range::new(3, 3)); + assert_eq!(Range::new(4, 4).grapheme_aligned(s), Range::new(4, 4)); + assert_eq!(Range::new(5, 5).grapheme_aligned(s), Range::new(4, 4)); + assert_eq!(Range::new(6, 6).grapheme_aligned(s), Range::new(6, 6)); + + // Forward. + assert_eq!(Range::new(0, 1).grapheme_aligned(s), Range::new(0, 2)); + assert_eq!(Range::new(1, 2).grapheme_aligned(s), Range::new(0, 2)); + assert_eq!(Range::new(2, 3).grapheme_aligned(s), Range::new(2, 3)); + assert_eq!(Range::new(3, 4).grapheme_aligned(s), Range::new(3, 4)); + assert_eq!(Range::new(4, 5).grapheme_aligned(s), Range::new(4, 6)); + assert_eq!(Range::new(5, 6).grapheme_aligned(s), Range::new(4, 6)); + + assert_eq!(Range::new(0, 2).grapheme_aligned(s), Range::new(0, 2)); + assert_eq!(Range::new(1, 3).grapheme_aligned(s), Range::new(0, 3)); + assert_eq!(Range::new(2, 4).grapheme_aligned(s), Range::new(2, 4)); + assert_eq!(Range::new(3, 5).grapheme_aligned(s), Range::new(3, 6)); + assert_eq!(Range::new(4, 6).grapheme_aligned(s), Range::new(4, 6)); + + // Reverse. + assert_eq!(Range::new(1, 0).grapheme_aligned(s), Range::new(2, 0)); + assert_eq!(Range::new(2, 1).grapheme_aligned(s), Range::new(2, 0)); + assert_eq!(Range::new(3, 2).grapheme_aligned(s), Range::new(3, 2)); + assert_eq!(Range::new(4, 3).grapheme_aligned(s), Range::new(4, 3)); + assert_eq!(Range::new(5, 4).grapheme_aligned(s), Range::new(6, 4)); + assert_eq!(Range::new(6, 5).grapheme_aligned(s), Range::new(6, 4)); + + assert_eq!(Range::new(2, 0).grapheme_aligned(s), Range::new(2, 0)); + assert_eq!(Range::new(3, 1).grapheme_aligned(s), Range::new(3, 0)); + assert_eq!(Range::new(4, 2).grapheme_aligned(s), Range::new(4, 2)); + assert_eq!(Range::new(5, 3).grapheme_aligned(s), Range::new(6, 3)); + assert_eq!(Range::new(6, 4).grapheme_aligned(s), Range::new(6, 4)); } #[test] - fn test_min_width_range() { + fn test_min_width_1() { let r = Rope::from_str("\r\nHi\r\n"); let s = r.slice(..); - assert_eq!(Range::new(0, 0).min_width_range(s, 1), (0, 2)); - assert_eq!(Range::new(0, 1).min_width_range(s, 1), (0, 2)); - assert_eq!(Range::new(1, 1).min_width_range(s, 1), (0, 2)); - assert_eq!(Range::new(1, 2).min_width_range(s, 1), (0, 2)); - assert_eq!(Range::new(2, 2).min_width_range(s, 1), (2, 3)); - assert_eq!(Range::new(2, 3).min_width_range(s, 1), (2, 3)); - assert_eq!(Range::new(1, 3).min_width_range(s, 1), (0, 3)); - assert_eq!(Range::new(3, 5).min_width_range(s, 1), (3, 6)); - assert_eq!(Range::new(4, 5).min_width_range(s, 1), (4, 6)); - assert_eq!(Range::new(5, 5).min_width_range(s, 1), (4, 6)); - assert_eq!(Range::new(6, 6).min_width_range(s, 1), (6, 6)); - - assert_eq!(Range::new(1, 0).min_width_range(s, 1), (0, 2)); - assert_eq!(Range::new(2, 1).min_width_range(s, 1), (0, 2)); - assert_eq!(Range::new(3, 2).min_width_range(s, 1), (2, 3)); - assert_eq!(Range::new(3, 1).min_width_range(s, 1), (0, 3)); - assert_eq!(Range::new(5, 3).min_width_range(s, 1), (3, 6)); - assert_eq!(Range::new(5, 4).min_width_range(s, 1), (4, 6)); - - assert_eq!(Range::new(3, 4).min_width_range(s, 3), (3, 6)); - assert_eq!(Range::new(4, 3).min_width_range(s, 3), (0, 4)); - assert_eq!(Range::new(3, 4).min_width_range(s, 20), (3, 6)); - assert_eq!(Range::new(4, 3).min_width_range(s, 20), (0, 4)); + // Zero-width. + assert_eq!(Range::new(0, 0).min_width_1(s), Range::new(0, 2)); + assert_eq!(Range::new(1, 1).min_width_1(s), Range::new(1, 2)); + assert_eq!(Range::new(2, 2).min_width_1(s), Range::new(2, 3)); + assert_eq!(Range::new(3, 3).min_width_1(s), Range::new(3, 4)); + assert_eq!(Range::new(4, 4).min_width_1(s), Range::new(4, 6)); + assert_eq!(Range::new(5, 5).min_width_1(s), Range::new(5, 6)); + assert_eq!(Range::new(6, 6).min_width_1(s), Range::new(6, 6)); + + // Forward. + assert_eq!(Range::new(0, 1).min_width_1(s), Range::new(0, 1)); + assert_eq!(Range::new(1, 2).min_width_1(s), Range::new(1, 2)); + assert_eq!(Range::new(2, 3).min_width_1(s), Range::new(2, 3)); + assert_eq!(Range::new(3, 4).min_width_1(s), Range::new(3, 4)); + assert_eq!(Range::new(4, 5).min_width_1(s), Range::new(4, 5)); + assert_eq!(Range::new(5, 6).min_width_1(s), Range::new(5, 6)); + + // Reverse. + assert_eq!(Range::new(1, 0).min_width_1(s), Range::new(1, 0)); + assert_eq!(Range::new(2, 1).min_width_1(s), Range::new(2, 1)); + assert_eq!(Range::new(3, 2).min_width_1(s), Range::new(3, 2)); + assert_eq!(Range::new(4, 3).min_width_1(s), Range::new(4, 3)); + assert_eq!(Range::new(5, 4).min_width_1(s), Range::new(5, 4)); + assert_eq!(Range::new(6, 5).min_width_1(s), Range::new(6, 5)); } #[test]