1 // Code for annotating snippets.
2 
3 use crate::Level;
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, Debug, PartialOrd, Ord, PartialEq, Eq)]
12 pub struct MultilineAnnotation {
13     pub depth: usize,
14     pub line_start: usize,
15     pub line_end: usize,
16     pub start_col: usize,
17     pub end_col: usize,
18     pub is_primary: bool,
19     pub label: Option<String>,
20     pub overlaps_exactly: bool,
21 }
22 
23 impl MultilineAnnotation {
increase_depth(&mut self)24     pub fn increase_depth(&mut self) {
25         self.depth += 1;
26     }
27 
28     /// Compare two `MultilineAnnotation`s considering only the `Span` they cover.
same_span(&self, other: &MultilineAnnotation) -> bool29     pub fn same_span(&self, other: &MultilineAnnotation) -> bool {
30         self.line_start == other.line_start
31             && self.line_end == other.line_end
32             && self.start_col == other.start_col
33             && self.end_col == other.end_col
34     }
35 
as_start(&self) -> Annotation36     pub fn as_start(&self) -> Annotation {
37         Annotation {
38             start_col: self.start_col,
39             end_col: self.start_col + 1,
40             is_primary: self.is_primary,
41             label: None,
42             annotation_type: AnnotationType::MultilineStart(self.depth),
43         }
44     }
45 
as_end(&self) -> Annotation46     pub fn as_end(&self) -> Annotation {
47         Annotation {
48             start_col: self.end_col.saturating_sub(1),
49             end_col: self.end_col,
50             is_primary: self.is_primary,
51             label: self.label.clone(),
52             annotation_type: AnnotationType::MultilineEnd(self.depth),
53         }
54     }
55 
as_line(&self) -> Annotation56     pub fn as_line(&self) -> Annotation {
57         Annotation {
58             start_col: 0,
59             end_col: 0,
60             is_primary: self.is_primary,
61             label: None,
62             annotation_type: AnnotationType::MultilineLine(self.depth),
63         }
64     }
65 }
66 
67 #[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
68 pub enum AnnotationType {
69     /// Annotation under a single line of code
70     Singleline,
71 
72     /// Annotation enclosing the first and last character of a multiline span
73     Multiline(MultilineAnnotation),
74 
75     // The Multiline type above is replaced with the following three in order
76     // to reuse the current label drawing code.
77     //
78     // Each of these corresponds to one part of the following diagram:
79     //
80     //     x |   foo(1 + bar(x,
81     //       |  _________^              < MultilineStart
82     //     x | |             y),        < MultilineLine
83     //       | |______________^ label   < MultilineEnd
84     //     x |       z);
85     /// Annotation marking the first character of a fully shown multiline span
86     MultilineStart(usize),
87     /// Annotation marking the last character of a fully shown multiline span
88     MultilineEnd(usize),
89     /// Line at the left enclosing the lines of a fully shown multiline span
90     // Just a placeholder for the drawing algorithm, to know that it shouldn't skip the first 4
91     // and last 2 lines of code. The actual line is drawn in `emit_message_default` and not in
92     // `draw_multiline_line`.
93     MultilineLine(usize),
94 }
95 
96 #[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
97 pub struct Annotation {
98     /// Start column, 0-based indexing -- counting *characters*, not
99     /// utf-8 bytes. Note that it is important that this field goes
100     /// first, so that when we sort, we sort orderings by start
101     /// column.
102     pub start_col: usize,
103 
104     /// End column within the line (exclusive)
105     pub end_col: usize,
106 
107     /// Is this annotation derived from primary span
108     pub is_primary: bool,
109 
110     /// Optional label to display adjacent to the annotation.
111     pub label: Option<String>,
112 
113     /// Is this a single line, multiline or multiline span minimized down to a
114     /// smaller span.
115     pub annotation_type: AnnotationType,
116 }
117 
118 impl Annotation {
119     /// Whether this annotation is a vertical line placeholder.
is_line(&self) -> bool120     pub fn is_line(&self) -> bool {
121         matches!(self.annotation_type, AnnotationType::MultilineLine(_))
122     }
123 
len(&self) -> usize124     pub fn len(&self) -> usize {
125         // Account for usize underflows
126         if self.end_col > self.start_col {
127             self.end_col - self.start_col
128         } else {
129             self.start_col - self.end_col
130         }
131     }
132 
has_label(&self) -> bool133     pub fn has_label(&self) -> bool {
134         if let Some(ref label) = self.label {
135             // Consider labels with no text as effectively not being there
136             // to avoid weird output with unnecessary vertical lines, like:
137             //
138             //     X | fn foo(x: u32) {
139             //       | -------^------
140             //       | |      |
141             //       | |
142             //       |
143             //
144             // Note that this would be the complete output users would see.
145             !label.is_empty()
146         } else {
147             false
148         }
149     }
150 
takes_space(&self) -> bool151     pub fn takes_space(&self) -> bool {
152         // Multiline annotations always have to keep vertical space.
153         matches!(
154             self.annotation_type,
155             AnnotationType::MultilineStart(_) | AnnotationType::MultilineEnd(_)
156         )
157     }
158 }
159 
160 #[derive(Debug)]
161 pub struct StyledString {
162     pub text: String,
163     pub style: Style,
164 }
165 
166 #[derive(Copy, Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
167 pub enum Style {
168     MainHeaderMsg,
169     HeaderMsg,
170     LineAndColumn,
171     LineNumber,
172     Quotation,
173     UnderlinePrimary,
174     UnderlineSecondary,
175     LabelPrimary,
176     LabelSecondary,
177     NoStyle,
178     Level(Level),
179     Highlight,
180 }
181