1 //! Representation of a `TextEdit`.
2 //!
3 //! `rust-analyzer` never mutates text itself and only sends diffs to clients,
4 //! so `TextEdit` is the ultimate representation of the work done by
5 //! rust-analyzer.
6
7 pub use text_size::{TextRange, TextSize};
8
9 /// `InsertDelete` -- a single "atomic" change to text
10 ///
11 /// Must not overlap with other `InDel`s
12 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
13 pub struct Indel {
14 pub insert: String,
15 /// Refers to offsets in the original text
16 pub delete: TextRange,
17 }
18
19 #[derive(Default, Debug, Clone)]
20 pub struct TextEdit {
21 /// Invariant: disjoint and sorted by `delete`.
22 indels: Vec<Indel>,
23 }
24
25 #[derive(Debug, Default, Clone)]
26 pub struct TextEditBuilder {
27 indels: Vec<Indel>,
28 }
29
30 impl Indel {
insert(offset: TextSize, text: String) -> Indel31 pub fn insert(offset: TextSize, text: String) -> Indel {
32 Indel::replace(TextRange::empty(offset), text)
33 }
delete(range: TextRange) -> Indel34 pub fn delete(range: TextRange) -> Indel {
35 Indel::replace(range, String::new())
36 }
replace(range: TextRange, replace_with: String) -> Indel37 pub fn replace(range: TextRange, replace_with: String) -> Indel {
38 Indel { delete: range, insert: replace_with }
39 }
40
apply(&self, text: &mut String)41 pub fn apply(&self, text: &mut String) {
42 let start: usize = self.delete.start().into();
43 let end: usize = self.delete.end().into();
44 text.replace_range(start..end, &self.insert);
45 }
46 }
47
48 impl TextEdit {
builder() -> TextEditBuilder49 pub fn builder() -> TextEditBuilder {
50 TextEditBuilder::default()
51 }
52
insert(offset: TextSize, text: String) -> TextEdit53 pub fn insert(offset: TextSize, text: String) -> TextEdit {
54 let mut builder = TextEdit::builder();
55 builder.insert(offset, text);
56 builder.finish()
57 }
58
delete(range: TextRange) -> TextEdit59 pub fn delete(range: TextRange) -> TextEdit {
60 let mut builder = TextEdit::builder();
61 builder.delete(range);
62 builder.finish()
63 }
64
replace(range: TextRange, replace_with: String) -> TextEdit65 pub fn replace(range: TextRange, replace_with: String) -> TextEdit {
66 let mut builder = TextEdit::builder();
67 builder.replace(range, replace_with);
68 builder.finish()
69 }
70
len(&self) -> usize71 pub fn len(&self) -> usize {
72 self.indels.len()
73 }
74
is_empty(&self) -> bool75 pub fn is_empty(&self) -> bool {
76 self.indels.is_empty()
77 }
78
iter(&self) -> std::slice::Iter<'_, Indel>79 pub fn iter(&self) -> std::slice::Iter<'_, Indel> {
80 self.into_iter()
81 }
82
apply(&self, text: &mut String)83 pub fn apply(&self, text: &mut String) {
84 match self.len() {
85 0 => return,
86 1 => {
87 self.indels[0].apply(text);
88 return;
89 }
90 _ => (),
91 }
92
93 let mut total_len = TextSize::of(&*text);
94 for indel in &self.indels {
95 total_len += TextSize::of(&indel.insert);
96 total_len -= indel.delete.end() - indel.delete.start();
97 }
98 let mut buf = String::with_capacity(total_len.into());
99 let mut prev = 0;
100 for indel in &self.indels {
101 let start: usize = indel.delete.start().into();
102 let end: usize = indel.delete.end().into();
103 if start > prev {
104 buf.push_str(&text[prev..start]);
105 }
106 buf.push_str(&indel.insert);
107 prev = end;
108 }
109 buf.push_str(&text[prev..text.len()]);
110 assert_eq!(TextSize::of(&buf), total_len);
111
112 // FIXME: figure out a way to mutate the text in-place or reuse the
113 // memory in some other way
114 *text = buf;
115 }
116
union(&mut self, other: TextEdit) -> Result<(), TextEdit>117 pub fn union(&mut self, other: TextEdit) -> Result<(), TextEdit> {
118 // FIXME: can be done without allocating intermediate vector
119 let mut all = self.iter().chain(other.iter()).collect::<Vec<_>>();
120 if !check_disjoint_and_sort(&mut all) {
121 return Err(other);
122 }
123
124 self.indels.extend(other.indels);
125 check_disjoint_and_sort(&mut self.indels);
126 // Only dedup deletions and replacements, keep all insertions
127 self.indels.dedup_by(|a, b| a == b && !a.delete.is_empty());
128 Ok(())
129 }
130
apply_to_offset(&self, offset: TextSize) -> Option<TextSize>131 pub fn apply_to_offset(&self, offset: TextSize) -> Option<TextSize> {
132 let mut res = offset;
133 for indel in &self.indels {
134 if indel.delete.start() >= offset {
135 break;
136 }
137 if offset < indel.delete.end() {
138 return None;
139 }
140 res += TextSize::of(&indel.insert);
141 res -= indel.delete.len();
142 }
143 Some(res)
144 }
145 }
146
147 impl IntoIterator for TextEdit {
148 type Item = Indel;
149 type IntoIter = std::vec::IntoIter<Indel>;
150
into_iter(self) -> Self::IntoIter151 fn into_iter(self) -> Self::IntoIter {
152 self.indels.into_iter()
153 }
154 }
155
156 impl<'a> IntoIterator for &'a TextEdit {
157 type Item = &'a Indel;
158 type IntoIter = std::slice::Iter<'a, Indel>;
159
into_iter(self) -> Self::IntoIter160 fn into_iter(self) -> Self::IntoIter {
161 self.indels.iter()
162 }
163 }
164
165 impl TextEditBuilder {
is_empty(&self) -> bool166 pub fn is_empty(&self) -> bool {
167 self.indels.is_empty()
168 }
replace(&mut self, range: TextRange, replace_with: String)169 pub fn replace(&mut self, range: TextRange, replace_with: String) {
170 self.indel(Indel::replace(range, replace_with));
171 }
delete(&mut self, range: TextRange)172 pub fn delete(&mut self, range: TextRange) {
173 self.indel(Indel::delete(range));
174 }
insert(&mut self, offset: TextSize, text: String)175 pub fn insert(&mut self, offset: TextSize, text: String) {
176 self.indel(Indel::insert(offset, text));
177 }
finish(self) -> TextEdit178 pub fn finish(self) -> TextEdit {
179 let mut indels = self.indels;
180 assert_disjoint_or_equal(&mut indels);
181 TextEdit { indels }
182 }
invalidates_offset(&self, offset: TextSize) -> bool183 pub fn invalidates_offset(&self, offset: TextSize) -> bool {
184 self.indels.iter().any(|indel| indel.delete.contains_inclusive(offset))
185 }
indel(&mut self, indel: Indel)186 fn indel(&mut self, indel: Indel) {
187 self.indels.push(indel);
188 if self.indels.len() <= 16 {
189 assert_disjoint_or_equal(&mut self.indels);
190 }
191 }
192 }
193
assert_disjoint_or_equal(indels: &mut [Indel])194 fn assert_disjoint_or_equal(indels: &mut [Indel]) {
195 assert!(check_disjoint_and_sort(indels));
196 }
197 // FIXME: Remove the impl Bound here, it shouldn't be needed
check_disjoint_and_sort(indels: &mut [impl std::borrow::Borrow<Indel>]) -> bool198 fn check_disjoint_and_sort(indels: &mut [impl std::borrow::Borrow<Indel>]) -> bool {
199 indels.sort_by_key(|indel| (indel.borrow().delete.start(), indel.borrow().delete.end()));
200 indels.iter().zip(indels.iter().skip(1)).all(|(l, r)| {
201 let l = l.borrow();
202 let r = r.borrow();
203 l.delete.end() <= r.delete.start() || l == r
204 })
205 }
206