From 77a266e818bf9d2eded39816b6a77de140234e4f Mon Sep 17 00:00:00 2001
From: Nathan Vegdahl <cessen@cessen.com>
Date: Mon, 28 Jun 2021 07:51:47 -0700
Subject: [PATCH] Better validation method APIs for `Range`.
This way they do less work, are more specific to what we actually
need, and they compose.
---
helix-core/src/graphemes.rs | 9 ++
helix-core/src/selection.rs | 245 ++++++++++++++++++++----------------
2 files changed, 148 insertions(+), 106 deletions(-)
diff --git a/helix-core/src/graphemes.rs b/helix-core/src/graphemes.rs
index f7bf66c0..0465fe51 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 906e2e53..4260c002 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.
+ /// Compute a possibly new range from this range, with its ends
+ /// shifted as needed to align with grapheme boundaries.
///
- /// 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.
- ///
- /// 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));
+ // 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));
- 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));
+ // 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));
- 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));
+ // 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]