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
|
//! Blank lines are a construct that occurs in the flow content type.
//!
//! They’re formed with the following BNF:
//!
//! ```bnf
//! blank_line ::= *(' ' '\t')
//! ```
//!
//! Blank lines are sometimes needed, such as to differentiate a paragraph
//! from another paragraph.
//! In several cases, blank lines are not needed between flow constructs,
//! such as between two headings.
//! Sometimes, whether blank lines are present, changes the behavior of how
//! HTML is rendered, such as whether blank lines are present between list
//! items in a list.
//! More than one blank line is never needed in `CommonMark`.
//!
//! Because blank lines can be empty (line endings are not considered part of
//! it), and events cannot be empty, blank lines are not present as a token.
//!
//! ## References
//!
//! * [`blank-line.js` in `micromark`](https://github.com/micromark/micromark/blob/main/packages/micromark-core-commonmark/dev/lib/blank-line.js)
//! * [*§ 4.9 Blank lines* in `CommonMark`](https://spec.commonmark.org/0.30/#blank-lines)
//!
//! <!-- To do: link `flow`, `heading`, `list`, `paragraph` -->
use crate::construct::partial_whitespace::start as whitespace;
use crate::tokenizer::{Code, State, StateFnResult, TokenType, Tokenizer};
/// Start of a blank line.
///
/// Note: `␠` represents a space character.
///
/// ```markdown
/// |␠␠
/// |
/// ```
pub fn start(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
tokenizer.attempt(
|tokenizer, code| whitespace(tokenizer, code, TokenType::BlankLineWhitespace),
|_ok| Box::new(after),
)(tokenizer, code)
}
/// After zero or more spaces or tabs, before a line ending or EOF.
///
/// Note: `␠` represents a space character.
///
/// ```markdown
/// |␠␠
/// |
/// ```
fn after(_tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
match code {
Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r') => {
(State::Ok, Some(vec![code]))
}
_ => (State::Nok, None),
}
}
|
