| 1 | //! Backslash escapes |
| 2 | //! |
| 3 | //! Allows escapes like `\*hello*`, also processes hard breaks at the end |
| 4 | //! of the line. |
| 5 | //! |
| 6 | //! <https://spec.commonmark.org/0.30/#backslash-escapes> |
| 7 | use crate::parser::inline::{InlineRule, InlineState, TextSpecial}; |
| 8 | use crate::plugins::cmark::inline::newline::Hardbreak; |
| 9 | use crate::{MarkdownIt, Node}; |
| 10 | |
| 11 | pub fn add(md: &mut MarkdownIt) { |
| 12 | md.inline.add_rule::<EscapeScanner>(); |
| 13 | } |
| 14 | |
| 15 | #[doc(hidden)] |
| 16 | pub struct EscapeScanner; |
| 17 | impl InlineRule for EscapeScanner { |
| 18 | const MARKER: char = '\\'; |
| 19 | |
| 20 | fn run(state: &mut InlineState) -> Option<(Node, usize)> { |
| 21 | let mut chars = state.src[state.pos..state.pos_max].chars(); |
| 22 | if chars.next().unwrap() != '\\' { return None; } |
| 23 | |
| 24 | match chars.next() { |
| 25 | Some('\n') => { |
| 26 | // skip leading whitespaces from next line |
| 27 | let mut len = 2; |
| 28 | while let Some(' ' | '\t') = chars.next() { |
| 29 | len += 1; |
| 30 | } |
| 31 | Some((Node::new(Hardbreak), len)) |
| 32 | } |
| 33 | Some(chr) => { |
| 34 | let start = state.pos; |
| 35 | let end = state.pos + 1 + chr.len_utf8(); |
| 36 | |
| 37 | let mut orig_str = "\\".to_owned(); |
| 38 | orig_str.push(chr); |
| 39 | |
| 40 | let content_str = match chr { |
| 41 | '\\' | '!' | '"' | '#' | '$' | '%' | '&' | '\'' | '(' | ')' | |
| 42 | '*' | '+' | ',' | '.' | '/' | ':' | ';' | '<' | '=' | '>' | '?' | |
| 43 | '@' | '[' | ']' | '^' | '_' | '`' | '{' | '|' | '}' | '~' | '-' => chr.into(), |
| 44 | _ => orig_str.clone() |
| 45 | }; |
| 46 | |
| 47 | let node = Node::new(TextSpecial { |
| 48 | content: content_str, |
| 49 | markup: orig_str, |
| 50 | info: "escape", |
| 51 | }); |
| 52 | Some((node, end - start)) |
| 53 | } |
| 54 | None => None |
| 55 | } |
| 56 | } |
| 57 | } |