aboutsummaryrefslogtreecommitdiff
path: root/crates/ra_text_edit/src/lib.rs
blob: c41bf324b6a7bccf16e8abbced65745635594e3a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
//! Representation of a `TextEdit`.
//!
//! `rust-analyzer` never mutates text itself and only sends diffs to clients,
//! so `TextEdit` is the ultimate representation of the work done by
//! rust-analyzer.

use text_size::{TextRange, TextSize};

/// `InsertDelete` -- a single "atomic" change to text
///
/// Must not overlap with other `InDel`s
#[derive(Debug, Clone)]
pub struct Indel {
    pub insert: String,
    /// Refers to offsets in the original text
    pub delete: TextRange,
}

#[derive(Debug, Clone)]
pub struct TextEdit {
    indels: Vec<Indel>,
}

#[derive(Debug, Default)]
pub struct TextEditBuilder {
    indels: Vec<Indel>,
}

impl Indel {
    pub fn insert(offset: TextSize, text: String) -> Indel {
        Indel::replace(TextRange::empty(offset), text)
    }
    pub fn delete(range: TextRange) -> Indel {
        Indel::replace(range, String::new())
    }
    pub fn replace(range: TextRange, replace_with: String) -> Indel {
        Indel { delete: range, insert: replace_with }
    }

    pub fn apply(&self, mut text: String) -> String {
        let start: usize = self.delete.start().into();
        let end: usize = self.delete.end().into();
        text.replace_range(start..end, &self.insert);
        text
    }
}

impl TextEdit {
    pub fn insert(offset: TextSize, text: String) -> TextEdit {
        let mut builder = TextEditBuilder::default();
        builder.insert(offset, text);
        builder.finish()
    }

    pub fn delete(range: TextRange) -> TextEdit {
        let mut builder = TextEditBuilder::default();
        builder.delete(range);
        builder.finish()
    }

    pub fn replace(range: TextRange, replace_with: String) -> TextEdit {
        let mut builder = TextEditBuilder::default();
        builder.replace(range, replace_with);
        builder.finish()
    }

    pub(crate) fn from_indels(mut indels: Vec<Indel>) -> TextEdit {
        indels.sort_by_key(|a| (a.delete.start(), a.delete.end()));
        for (a1, a2) in indels.iter().zip(indels.iter().skip(1)) {
            assert!(a1.delete.end() <= a2.delete.start())
        }
        TextEdit { indels }
    }

    pub fn as_indels(&self) -> &[Indel] {
        &self.indels
    }

    pub fn apply(&self, text: &str) -> String {
        let mut total_len = TextSize::of(text);
        for indel in self.indels.iter() {
            total_len += TextSize::of(&indel.insert);
            total_len -= indel.delete.end() - indel.delete.start();
        }
        let mut buf = String::with_capacity(total_len.into());
        let mut prev = 0;
        for indel in self.indels.iter() {
            let start: usize = indel.delete.start().into();
            let end: usize = indel.delete.end().into();
            if start > prev {
                buf.push_str(&text[prev..start]);
            }
            buf.push_str(&indel.insert);
            prev = end;
        }
        buf.push_str(&text[prev..text.len()]);
        assert_eq!(TextSize::of(&buf), total_len);
        buf
    }

    pub fn apply_to_offset(&self, offset: TextSize) -> Option<TextSize> {
        let mut res = offset;
        for indel in self.indels.iter() {
            if indel.delete.start() >= offset {
                break;
            }
            if offset < indel.delete.end() {
                return None;
            }
            res += TextSize::of(&indel.insert);
            res -= indel.delete.len();
        }
        Some(res)
    }
}

impl TextEditBuilder {
    pub fn replace(&mut self, range: TextRange, replace_with: String) {
        self.indels.push(Indel::replace(range, replace_with))
    }
    pub fn delete(&mut self, range: TextRange) {
        self.indels.push(Indel::delete(range))
    }
    pub fn insert(&mut self, offset: TextSize, text: String) {
        self.indels.push(Indel::insert(offset, text))
    }
    pub fn finish(self) -> TextEdit {
        TextEdit::from_indels(self.indels)
    }
    pub fn invalidates_offset(&self, offset: TextSize) -> bool {
        self.indels.iter().any(|indel| indel.delete.contains_inclusive(offset))
    }
}