crashkeys.dev
Markdown parser fork with extended syntax for personal use.
1//! Paragraph occurs in the [content][] content type.
2//!
3//! ## Grammar
4//!
5//! Paragraph forms with the following BNF
6//! (<small>see [construct][crate::construct] for character groups</small>):
7//!
8//! ```bnf
9//! ; Restriction: lines cannot start other flow constructs.
10//! ; Restriction: lines cannot be blank.
11//! paragraph ::= 1*line *(eol 1*line)
12//! ```
13//!
14//! This construct must be followed by an eol (line ending) or eof (end of
15//! file), like flow constructs.
16//!
17//! Paragraphs can contain line endings and whitespace, but they are not
18//! allowed to contain blank lines, or to be blank themselves.
19//!
20//! The paragraph is interpreted as the [text][] content type.
21//! That means that [autolinks][autolink], [code (text)][raw_text], etc are
22//! allowed.
23//!
24//! ## HTML
25//!
26//! Paragraphs in markdown relate to the `<p>` element in HTML.
27//! See [*§ 4.4.1 The `p` element* in the HTML spec][html] for more info.
28//!
29//! ## Tokens
30//!
31//! * [`Paragraph`][Name::Paragraph]
32//!
33//! ## References
34//!
35//! * [`content.js` in `micromark`](https://github.com/micromark/micromark/blob/main/packages/micromark-core-commonmark/dev/lib/content.js)
36//! * [*§ 4.8 Paragraphs* in `CommonMark`](https://spec.commonmark.org/0.31/#paragraphs)
37//!
38//! [content]: crate::construct::content
39//! [text]: crate::construct::text
40//! [autolink]: crate::construct::autolink
41//! [raw_text]: crate::construct::raw_text
42//! [html]: https://html.spec.whatwg.org/multipage/grouping-content.html#the-p-element
43
44use crate::event::{Content, Link, Name};
45use crate::state::{Name as StateName, State};
46use crate::subtokenize::link;
47use crate::tokenizer::Tokenizer;
48
49/// Paragraph start.
50///
51/// ```markdown
52/// > | abc
53/// ^
54/// | def
55/// ```
56pub fn start(tokenizer: &mut Tokenizer) -> State {
57 debug_assert!(tokenizer.current.is_some());
58 tokenizer.enter(Name::Paragraph);
59 State::Retry(StateName::ParagraphLineStart)
60}
61
62/// Start of a line in a paragraph.
63///
64/// ```markdown
65/// > | abc
66/// ^
67/// > | def
68/// ^
69/// ```
70pub fn line_start(tokenizer: &mut Tokenizer) -> State {
71 debug_assert!(tokenizer.current.is_some());
72 tokenizer.enter_link(
73 Name::Data,
74 Link {
75 previous: None,
76 next: None,
77 content: Content::Text,
78 },
79 );
80
81 if tokenizer.tokenize_state.connect {
82 let index = tokenizer.events.len() - 1;
83 link(&mut tokenizer.events, index);
84 } else {
85 tokenizer.tokenize_state.connect = true;
86 }
87
88 State::Retry(StateName::ParagraphInside)
89}
90
91/// In paragraph.
92///
93/// ```markdown
94/// > | abc
95/// ^^^
96/// ```
97pub fn inside(tokenizer: &mut Tokenizer) -> State {
98 match tokenizer.current {
99 None => {
100 tokenizer.tokenize_state.connect = false;
101 tokenizer.exit(Name::Data);
102 tokenizer.exit(Name::Paragraph);
103 State::Ok
104 }
105 Some(b'\n') => {
106 tokenizer.consume();
107 tokenizer.exit(Name::Data);
108 State::Next(StateName::ParagraphLineStart)
109 }
110 _ => {
111 tokenizer.consume();
112 State::Next(StateName::ParagraphInside)
113 }
114 }
115}