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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
|
use crate::compositor::{Component, Compositor, Context, EventResult};
use crossterm::event::{Event, KeyCode, KeyEvent, KeyModifiers};
use tui::{
buffer::Buffer as Surface,
layout::Rect,
style::{Color, Style},
text::Text,
};
use std::borrow::Cow;
use helix_core::Position;
use helix_view::{Editor, Theme};
pub struct Markdown {
contents: String,
}
// TODO: pre-render and self reference via Pin
// better yet, just use Tendril + subtendril for references
impl Markdown {
pub fn new(contents: String) -> Self {
Self { contents }
}
}
fn parse<'a>(contents: &'a str, theme: Option<&Theme>) -> tui::text::Text<'a> {
use pulldown_cmark::{CodeBlockKind, CowStr, Event, Options, Parser, Tag};
use tui::text::{Span, Spans, Text};
// also 2021-03-04T16:33:58.553 helix_lsp::transport [INFO] <- {"contents":{"kind":"markdown","value":"\n```rust\ncore::num\n```\n\n```rust\npub const fn saturating_sub(self, rhs:Self) ->Self\n```\n\n---\n\n```rust\n```"},"range":{"end":{"character":61,"line":101},"start":{"character":47,"line":101}}}
let text = "\n```rust\ncore::iter::traits::iterator::Iterator\n```\n\n```rust\nfn collect<B: FromIterator<Self::Item>>(self) -> B\nwhere\n Self: Sized,\n```\n\n---\n\nTransforms an iterator into a collection.\n\n`collect()` can take anything iterable, and turn it into a relevant\ncollection. This is one of the more powerful methods in the standard\nlibrary, used in a variety of contexts.\n\nThe most basic pattern in which `collect()` is used is to turn one\ncollection into another. You take a collection, call [`iter`](https://doc.rust-lang.org/nightly/core/iter/traits/iterator/trait.Iterator.html) on it,\ndo a bunch of transformations, and then `collect()` at the end.\n\n`collect()` can also create instances of types that are not typical\ncollections. For example, a [`String`](https://doc.rust-lang.org/nightly/core/iter/std/string/struct.String.html) can be built from [`char`](type@char)s,\nand an iterator of [`Result<T, E>`](https://doc.rust-lang.org/nightly/core/result/enum.Result.html) items can be collected\ninto `Result<Collection<T>, E>`. See the examples below for more.\n\nBecause `collect()` is so general, it can cause problems with type\ninference. As such, `collect()` is one of the few times you'll see\nthe syntax affectionately known as the 'turbofish': `::<>`. This\nhelps the inference algorithm understand specifically which collection\nyou're trying to collect into.\n\n# Examples\n\nBasic usage:\n\n```rust\nlet a = [1, 2, 3];\n\nlet doubled: Vec<i32> = a.iter()\n .map(|&x| x * 2)\n .collect();\n\nassert_eq!(vec![2, 4, 6], doubled);\n```\n\nNote that we needed the `: Vec<i32>` on the left-hand side. This is because\nwe could collect into, for example, a [`VecDeque<T>`](https://doc.rust-lang.org/nightly/core/iter/std/collections/struct.VecDeque.html) instead:\n\n```rust\nuse std::collections::VecDeque;\n\nlet a = [1, 2, 3];\n\nlet doubled: VecDeque<i32> = a.iter().map(|&x| x * 2).collect();\n\nassert_eq!(2, doubled[0]);\nassert_eq!(4, doubled[1]);\nassert_eq!(6, doubled[2]);\n```\n\nUsing the 'turbofish' instead of annotating `doubled`:\n\n```rust\nlet a = [1, 2, 3];\n\nlet doubled = a.iter().map(|x| x * 2).collect::<Vec<i32>>();\n\nassert_eq!(vec![2, 4, 6], doubled);\n```\n\nBecause `collect()` only cares about what you're collecting into, you can\nstill use a partial type hint, `_`, with the turbofish:\n\n```rust\nlet a = [1, 2, 3];\n\nlet doubled = a.iter().map(|x| x * 2).collect::<Vec<_>>();\n\nassert_eq!(vec![2, 4, 6], doubled);\n```\n\nUsing `collect()` to make a [`String`](https://doc.rust-lang.org/nightly/core/iter/std/string/struct.String.html):\n\n```rust\nlet chars = ['g', 'd', 'k', 'k', 'n'];\n\nlet hello: String = chars.iter()\n .map(|&x| x as u8)\n .map(|x| (x + 1) as char)\n .collect();\n\nassert_eq!(\"hello\", hello);\n```\n\nIf you have a list of [`Result<T, E>`](https://doc.rust-lang.org/nightly/core/result/enum.Result.html)s, you can use `collect()` to\nsee if any of them failed:\n\n```rust\nlet results = [Ok(1), Err(\"nope\"), Ok(3), Err(\"bad\")];\n\nlet result: Result<Vec<_>, &str> = results.iter().cloned().collect();\n\n// gives us the first error\nassert_eq!(Err(\"nope\"), result);\n\nlet results = [Ok(1), Ok(3)];\n\nlet result: Result<Vec<_>, &str> = results.iter().cloned().collect();\n\n// gives us the list of answers\nassert_eq!(Ok(vec![1, 3]), result);\n```";
let mut options = Options::empty();
options.insert(Options::ENABLE_STRIKETHROUGH);
let parser = Parser::new_ext(contents, options);
// TODO: if possible, render links as terminal hyperlinks: https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
let mut tags = Vec::new();
let mut spans = Vec::new();
let mut lines = Vec::new();
fn to_span(text: pulldown_cmark::CowStr) -> Span {
use std::ops::Deref;
Span::raw::<std::borrow::Cow<_>>(match text {
CowStr::Borrowed(s) => s.to_string().into(), // could retain borrow
CowStr::Boxed(s) => s.to_string().into(),
CowStr::Inlined(s) => s.deref().to_owned().into(),
})
}
let text_style = Style::default().fg(Color::Rgb(164, 160, 232)); // lavender
let code_style = Style::default().fg(Color::Rgb(255, 255, 255)); // white
let heading_style = Style::default().fg(Color::Rgb(219, 191, 239)); // lilac
for event in parser {
match event {
Event::Start(tag) => tags.push(tag),
Event::End(tag) => {
tags.pop();
match tag {
Tag::Heading(_) | Tag::Paragraph | Tag::CodeBlock(CodeBlockKind::Fenced(_)) => {
// whenever code block or paragraph closes, new line
let spans = std::mem::take(&mut spans);
if !spans.is_empty() {
lines.push(Spans::from(spans));
}
lines.push(Spans::default());
}
_ => (),
}
}
Event::Text(text) => {
// TODO: temp workaround
if let Some(Tag::CodeBlock(CodeBlockKind::Fenced(language))) = tags.last() {
if let Some(theme) = theme {
use helix_core::syntax::{self, HighlightEvent, Syntax};
use helix_core::Rope;
let rope = Rope::from(text.as_ref());
let syntax = syntax::LOADER
.get()
.unwrap()
.language_config_for_scope(&format!("source.{}", language))
.and_then(|config| config.highlight_config(theme.scopes()))
.map(|config| Syntax::new(&rope, config));
if let Some(mut syntax) = syntax {
// if we have a syntax available, highlight_iter and generate spans
let mut highlights = Vec::new();
for event in syntax.highlight_iter(rope.slice(..), None, None, |_| None)
{
match event.unwrap() {
HighlightEvent::HighlightStart(span) => {
highlights.push(span);
}
HighlightEvent::HighlightEnd => {
highlights.pop();
}
HighlightEvent::Source { start, end } => {
let style = match highlights.first() {
Some(span) => {
theme.get(theme.scopes()[span.0].as_str())
}
None => text_style,
};
// TODO: replace tabs with indentation
let mut slice = &text[start..end];
while let Some(end) = slice.find('\n') {
// emit span up to newline
let text = &slice[..end];
let text = text.replace('\t', " "); // replace tabs
let span = Span::styled(text, style);
spans.push(span);
// truncate slice to after newline
slice = &slice[end + 1..];
// make a new line
let spans = std::mem::take(&mut spans);
lines.push(Spans::from(spans));
}
// if there's anything left, emit it too
if !slice.is_empty() {
let span =
Span::styled(slice.replace('\t', " "), style);
spans.push(span);
}
}
}
}
} else {
for line in text.lines() {
let mut span = Span::styled(line.to_string(), code_style);
lines.push(Spans::from(span));
}
}
} else {
for line in text.lines() {
let mut span = Span::styled(line.to_string(), code_style);
lines.push(Spans::from(span));
}
}
} else if let Some(Tag::Heading(_)) = tags.last() {
let mut span = to_span(text);
span.style = heading_style;
spans.push(span);
} else {
let mut span = to_span(text);
span.style = text_style;
spans.push(span);
}
}
Event::Code(text) | Event::Html(text) => {
log::warn!("code {:?}", text);
let mut span = to_span(text);
span.style = code_style;
spans.push(span);
}
Event::SoftBreak | Event::HardBreak => {
// let spans = std::mem::replace(&mut spans, Vec::new());
// lines.push(Spans::from(spans));
spans.push(Span::raw(" "));
}
Event::Rule => {
lines.push(Spans::from("---"));
lines.push(Spans::default());
}
// TaskListMarker(bool) true if checked
_ => {
log::warn!("unhandled markdown event {:?}", event);
}
}
// build up a vec of Paragraph tui widgets
}
if !spans.is_empty() {
lines.push(Spans::from(spans));
}
// if last line is empty, remove it
if let Some(line) = lines.last() {
if line.0.is_empty() {
lines.pop();
}
}
Text::from(lines)
}
impl Component for Markdown {
fn render(&self, area: Rect, surface: &mut Surface, cx: &mut Context) {
use tui::widgets::{Paragraph, Widget, Wrap};
let text = parse(&self.contents, Some(&cx.editor.theme));
let par = Paragraph::new(text)
.wrap(Wrap { trim: false })
.scroll((cx.scroll.unwrap_or_default() as u16, 0));
let area = Rect::new(area.x + 1, area.y + 1, area.width - 2, area.height - 2);
par.render(area, surface);
}
fn required_size(&mut self, viewport: (u16, u16)) -> Option<(u16, u16)> {
let contents = parse(&self.contents, None);
let padding = 2;
let width = std::cmp::min(contents.width() as u16 + padding, viewport.0);
let height = std::cmp::min(contents.height() as u16 + padding, viewport.1);
Some((width, height))
}
}
|
