anchor.rs

  1use super::{ExcerptId, MultiBufferSnapshot, ToOffset, ToPoint};
  2use language::{OffsetUtf16, Point, TextDimension};
  3use std::{
  4    cmp::Ordering,
  5    ops::{Range, Sub},
  6};
  7use sum_tree::Bias;
  8
  9#[derive(Clone, Copy, Eq, PartialEq, Hash)]
 10pub struct Anchor {
 11    pub excerpt_id: ExcerptId,
 12    pub text_anchor: text::Anchor,
 13    pub diff_base_anchor: Option<text::Anchor>,
 14}
 15
 16impl std::fmt::Debug for Anchor {
 17    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 18        if self.is_min() {
 19            return write!(f, "Anchor::min({:?})", self.text_anchor.buffer_id);
 20        }
 21        if self.is_max() {
 22            return write!(f, "Anchor::max({:?})", self.text_anchor.buffer_id);
 23        }
 24
 25        f.debug_struct("Anchor")
 26            .field("excerpt_id", &self.excerpt_id)
 27            .field("text_anchor", &self.text_anchor)
 28            .field("diff_base_anchor", &self.diff_base_anchor)
 29            .finish()
 30    }
 31}
 32
 33impl Anchor {
 34    pub fn with_diff_base_anchor(self, diff_base_anchor: text::Anchor) -> Self {
 35        Self {
 36            diff_base_anchor: Some(diff_base_anchor),
 37            ..self
 38        }
 39    }
 40
 41    pub fn in_buffer(excerpt_id: ExcerptId, text_anchor: text::Anchor) -> Self {
 42        Self {
 43            excerpt_id,
 44            text_anchor,
 45            diff_base_anchor: None,
 46        }
 47    }
 48
 49    pub fn range_in_buffer(excerpt_id: ExcerptId, range: Range<text::Anchor>) -> Range<Self> {
 50        Self::in_buffer(excerpt_id, range.start)..Self::in_buffer(excerpt_id, range.end)
 51    }
 52
 53    pub fn min() -> Self {
 54        Self {
 55            excerpt_id: ExcerptId::min(),
 56            text_anchor: text::Anchor::MIN,
 57            diff_base_anchor: None,
 58        }
 59    }
 60
 61    pub fn max() -> Self {
 62        Self {
 63            excerpt_id: ExcerptId::max(),
 64            text_anchor: text::Anchor::MAX,
 65            diff_base_anchor: None,
 66        }
 67    }
 68
 69    pub fn is_min(&self) -> bool {
 70        self.excerpt_id == ExcerptId::min()
 71            && self.text_anchor.is_min()
 72            && self.diff_base_anchor.is_none()
 73    }
 74
 75    pub fn is_max(&self) -> bool {
 76        self.excerpt_id == ExcerptId::max()
 77            && self.text_anchor.is_max()
 78            && self.diff_base_anchor.is_none()
 79    }
 80
 81    pub fn cmp(&self, other: &Anchor, snapshot: &MultiBufferSnapshot) -> Ordering {
 82        if self == other {
 83            return Ordering::Equal;
 84        }
 85
 86        let self_excerpt_id = snapshot.latest_excerpt_id(self.excerpt_id);
 87        let other_excerpt_id = snapshot.latest_excerpt_id(other.excerpt_id);
 88
 89        let excerpt_id_cmp = self_excerpt_id.cmp(&other_excerpt_id, snapshot);
 90        if excerpt_id_cmp.is_ne() {
 91            return excerpt_id_cmp;
 92        }
 93        if self_excerpt_id == ExcerptId::max()
 94            && self.text_anchor.is_max()
 95            && self.text_anchor.is_max()
 96            && self.diff_base_anchor.is_none()
 97            && other.diff_base_anchor.is_none()
 98        {
 99            return Ordering::Equal;
100        }
101        if let Some(excerpt) = snapshot.excerpt(self_excerpt_id) {
102            let text_cmp = self.text_anchor.cmp(&other.text_anchor, &excerpt.buffer);
103            if text_cmp.is_ne() {
104                return text_cmp;
105            }
106            if (self.diff_base_anchor.is_some() || other.diff_base_anchor.is_some())
107                && let Some(base_text) = snapshot
108                    .diffs
109                    .get(&excerpt.buffer_id)
110                    .map(|diff| diff.base_text())
111            {
112                let self_anchor = self.diff_base_anchor.filter(|a| base_text.can_resolve(a));
113                let other_anchor = other.diff_base_anchor.filter(|a| base_text.can_resolve(a));
114                return match (self_anchor, other_anchor) {
115                    (Some(a), Some(b)) => a.cmp(&b, base_text),
116                    (Some(_), None) => match other.text_anchor.bias {
117                        Bias::Left => Ordering::Greater,
118                        Bias::Right => Ordering::Less,
119                    },
120                    (None, Some(_)) => match self.text_anchor.bias {
121                        Bias::Left => Ordering::Less,
122                        Bias::Right => Ordering::Greater,
123                    },
124                    (None, None) => Ordering::Equal,
125                };
126            }
127        }
128        Ordering::Equal
129    }
130
131    pub fn bias(&self) -> Bias {
132        self.text_anchor.bias
133    }
134
135    pub fn bias_left(&self, snapshot: &MultiBufferSnapshot) -> Anchor {
136        if self.text_anchor.bias != Bias::Left
137            && let Some(excerpt) = snapshot.excerpt(self.excerpt_id)
138        {
139            return Self {
140                excerpt_id: excerpt.id,
141                text_anchor: self.text_anchor.bias_left(&excerpt.buffer),
142                diff_base_anchor: self.diff_base_anchor.map(|a| {
143                    if let Some(base_text) = snapshot
144                        .diffs
145                        .get(&excerpt.buffer_id)
146                        .map(|diff| diff.base_text())
147                        && a.buffer_id == Some(base_text.remote_id())
148                    {
149                        return a.bias_left(base_text);
150                    }
151                    a
152                }),
153            };
154        }
155        *self
156    }
157
158    pub fn bias_right(&self, snapshot: &MultiBufferSnapshot) -> Anchor {
159        if self.text_anchor.bias != Bias::Right
160            && let Some(excerpt) = snapshot.excerpt(self.excerpt_id)
161        {
162            return Self {
163                excerpt_id: excerpt.id,
164                text_anchor: self.text_anchor.bias_right(&excerpt.buffer),
165                diff_base_anchor: self.diff_base_anchor.map(|a| {
166                    if let Some(base_text) = snapshot
167                        .diffs
168                        .get(&excerpt.buffer_id)
169                        .map(|diff| diff.base_text())
170                        && a.buffer_id == Some(base_text.remote_id())
171                    {
172                        return a.bias_right(base_text);
173                    }
174                    a
175                }),
176            };
177        }
178        *self
179    }
180
181    pub fn summary<D>(&self, snapshot: &MultiBufferSnapshot) -> D
182    where
183        D: TextDimension + Ord + Sub<D, Output = D>,
184    {
185        snapshot.summary_for_anchor(self)
186    }
187
188    pub fn is_valid(&self, snapshot: &MultiBufferSnapshot) -> bool {
189        if self.is_min() || self.is_max() {
190            true
191        } else if let Some(excerpt) = snapshot.excerpt(self.excerpt_id) {
192            (self.text_anchor == excerpt.range.context.start
193                || self.text_anchor == excerpt.range.context.end
194                || self.text_anchor.is_valid(&excerpt.buffer))
195                && excerpt.contains(self)
196        } else {
197            false
198        }
199    }
200}
201
202impl ToOffset for Anchor {
203    fn to_offset(&self, snapshot: &MultiBufferSnapshot) -> usize {
204        self.summary(snapshot)
205    }
206    fn to_offset_utf16(&self, snapshot: &MultiBufferSnapshot) -> OffsetUtf16 {
207        self.summary(snapshot)
208    }
209}
210
211impl ToPoint for Anchor {
212    fn to_point<'a>(&self, snapshot: &MultiBufferSnapshot) -> Point {
213        self.summary(snapshot)
214    }
215    fn to_point_utf16(&self, snapshot: &MultiBufferSnapshot) -> rope::PointUtf16 {
216        self.summary(snapshot)
217    }
218}
219
220pub trait AnchorRangeExt {
221    fn cmp(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> Ordering;
222    fn includes(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> bool;
223    fn overlaps(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> bool;
224    fn to_offset(&self, content: &MultiBufferSnapshot) -> Range<usize>;
225    fn to_point(&self, content: &MultiBufferSnapshot) -> Range<Point>;
226}
227
228impl AnchorRangeExt for Range<Anchor> {
229    fn cmp(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> Ordering {
230        match self.start.cmp(&other.start, buffer) {
231            Ordering::Equal => other.end.cmp(&self.end, buffer),
232            ord => ord,
233        }
234    }
235
236    fn includes(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> bool {
237        self.start.cmp(&other.start, buffer).is_le() && other.end.cmp(&self.end, buffer).is_le()
238    }
239
240    fn overlaps(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> bool {
241        self.end.cmp(&other.start, buffer).is_ge() && self.start.cmp(&other.end, buffer).is_le()
242    }
243
244    fn to_offset(&self, content: &MultiBufferSnapshot) -> Range<usize> {
245        self.start.to_offset(content)..self.end.to_offset(content)
246    }
247
248    fn to_point(&self, content: &MultiBufferSnapshot) -> Range<Point> {
249        self.start.to_point(content)..self.end.to_point(content)
250    }
251}
252
253#[derive(Clone, Copy, Eq, PartialEq, Debug, Hash, Ord, PartialOrd)]
254pub struct Offset(pub usize);