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1 // Code for annotating snippets.
2 
3 use crate::{Level, Loc};
4 
5 #[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
6 pub struct Line {
7     pub line_index: usize,
8     pub annotations: Vec<Annotation>,
9 }
10 
11 #[derive(Clone, Copy, Debug, PartialOrd, Ord, PartialEq, Eq, Default)]
12 pub struct AnnotationColumn {
13     /// the (0-indexed) column for *display* purposes, counted in characters, not utf-8 bytes
14     pub display: usize,
15     /// the (0-indexed) column in the file, counted in characters, not utf-8 bytes.
16     ///
17     /// this may be different from `self.display`,
18     /// e.g. if the file contains hard tabs, because we convert tabs to spaces for error messages.
19     ///
20     /// for example:
21     /// ```text
22     /// (hard tab)hello
23     ///           ^ this is display column 4, but file column 1
24     /// ```
25     ///
26     /// we want to keep around the correct file offset so that column numbers in error messages
27     /// are correct. (motivated by <https://github.com/rust-lang/rust/issues/109537>)
28     pub file: usize,
29 }
30 
31 impl AnnotationColumn {
from_loc(loc: &Loc) -> AnnotationColumn32     pub fn from_loc(loc: &Loc) -> AnnotationColumn {
33         AnnotationColumn { display: loc.col_display, file: loc.col.0 }
34     }
35 }
36 
37 #[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
38 pub struct MultilineAnnotation {
39     pub depth: usize,
40     pub line_start: usize,
41     pub line_end: usize,
42     pub start_col: AnnotationColumn,
43     pub end_col: AnnotationColumn,
44     pub is_primary: bool,
45     pub label: Option<String>,
46     pub overlaps_exactly: bool,
47 }
48 
49 impl MultilineAnnotation {
increase_depth(&mut self)50     pub fn increase_depth(&mut self) {
51         self.depth += 1;
52     }
53 
54     /// Compare two `MultilineAnnotation`s considering only the `Span` they cover.
same_span(&self, other: &MultilineAnnotation) -> bool55     pub fn same_span(&self, other: &MultilineAnnotation) -> bool {
56         self.line_start == other.line_start
57             && self.line_end == other.line_end
58             && self.start_col == other.start_col
59             && self.end_col == other.end_col
60     }
61 
as_start(&self) -> Annotation62     pub fn as_start(&self) -> Annotation {
63         Annotation {
64             start_col: self.start_col,
65             end_col: AnnotationColumn {
66                 // these might not correspond to the same place anymore,
67                 // but that's okay for our purposes
68                 display: self.start_col.display + 1,
69                 file: self.start_col.file + 1,
70             },
71             is_primary: self.is_primary,
72             label: None,
73             annotation_type: AnnotationType::MultilineStart(self.depth),
74         }
75     }
76 
as_end(&self) -> Annotation77     pub fn as_end(&self) -> Annotation {
78         Annotation {
79             start_col: AnnotationColumn {
80                 // these might not correspond to the same place anymore,
81                 // but that's okay for our purposes
82                 display: self.end_col.display.saturating_sub(1),
83                 file: self.end_col.file.saturating_sub(1),
84             },
85             end_col: self.end_col,
86             is_primary: self.is_primary,
87             label: self.label.clone(),
88             annotation_type: AnnotationType::MultilineEnd(self.depth),
89         }
90     }
91 
as_line(&self) -> Annotation92     pub fn as_line(&self) -> Annotation {
93         Annotation {
94             start_col: Default::default(),
95             end_col: Default::default(),
96             is_primary: self.is_primary,
97             label: None,
98             annotation_type: AnnotationType::MultilineLine(self.depth),
99         }
100     }
101 }
102 
103 #[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
104 pub enum AnnotationType {
105     /// Annotation under a single line of code
106     Singleline,
107 
108     // The Multiline type above is replaced with the following three in order
109     // to reuse the current label drawing code.
110     //
111     // Each of these corresponds to one part of the following diagram:
112     //
113     //     x |   foo(1 + bar(x,
114     //       |  _________^              < MultilineStart
115     //     x | |             y),        < MultilineLine
116     //       | |______________^ label   < MultilineEnd
117     //     x |       z);
118     /// Annotation marking the first character of a fully shown multiline span
119     MultilineStart(usize),
120     /// Annotation marking the last character of a fully shown multiline span
121     MultilineEnd(usize),
122     /// Line at the left enclosing the lines of a fully shown multiline span
123     // Just a placeholder for the drawing algorithm, to know that it shouldn't skip the first 4
124     // and last 2 lines of code. The actual line is drawn in `emit_message_default` and not in
125     // `draw_multiline_line`.
126     MultilineLine(usize),
127 }
128 
129 #[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
130 pub struct Annotation {
131     /// Start column.
132     /// Note that it is important that this field goes
133     /// first, so that when we sort, we sort orderings by start
134     /// column.
135     pub start_col: AnnotationColumn,
136 
137     /// End column within the line (exclusive)
138     pub end_col: AnnotationColumn,
139 
140     /// Is this annotation derived from primary span
141     pub is_primary: bool,
142 
143     /// Optional label to display adjacent to the annotation.
144     pub label: Option<String>,
145 
146     /// Is this a single line, multiline or multiline span minimized down to a
147     /// smaller span.
148     pub annotation_type: AnnotationType,
149 }
150 
151 impl Annotation {
152     /// Whether this annotation is a vertical line placeholder.
is_line(&self) -> bool153     pub fn is_line(&self) -> bool {
154         matches!(self.annotation_type, AnnotationType::MultilineLine(_))
155     }
156 
157     /// Length of this annotation as displayed in the stderr output
len(&self) -> usize158     pub fn len(&self) -> usize {
159         // Account for usize underflows
160         if self.end_col.display > self.start_col.display {
161             self.end_col.display - self.start_col.display
162         } else {
163             self.start_col.display - self.end_col.display
164         }
165     }
166 
has_label(&self) -> bool167     pub fn has_label(&self) -> bool {
168         if let Some(ref label) = self.label {
169             // Consider labels with no text as effectively not being there
170             // to avoid weird output with unnecessary vertical lines, like:
171             //
172             //     X | fn foo(x: u32) {
173             //       | -------^------
174             //       | |      |
175             //       | |
176             //       |
177             //
178             // Note that this would be the complete output users would see.
179             !label.is_empty()
180         } else {
181             false
182         }
183     }
184 
takes_space(&self) -> bool185     pub fn takes_space(&self) -> bool {
186         // Multiline annotations always have to keep vertical space.
187         matches!(
188             self.annotation_type,
189             AnnotationType::MultilineStart(_) | AnnotationType::MultilineEnd(_)
190         )
191     }
192 }
193 
194 #[derive(Debug)]
195 pub struct StyledString {
196     pub text: String,
197     pub style: Style,
198 }
199 
200 #[derive(Copy, Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
201 pub enum Style {
202     MainHeaderMsg,
203     HeaderMsg,
204     LineAndColumn,
205     LineNumber,
206     Quotation,
207     UnderlinePrimary,
208     UnderlineSecondary,
209     LabelPrimary,
210     LabelSecondary,
211     NoStyle,
212     Level(Level),
213     Highlight,
214     Addition,
215     Removal,
216 }
217