mdx/
ast.rs

1use nom::{character::complete::*, multi::many1_count, IResult};
2use nom_supreme::{
3    error::ErrorTree,
4    final_parser::{final_parser, Location},
5};
6use std::fmt;
7
8pub mod headings;
9pub mod paragraphs;
10pub mod thematic_breaks;
11
12pub use headings::{atx_heading, ATXHeading};
13pub use paragraphs::{paragraph, Paragraph};
14pub use thematic_breaks::{thematic_break, ThematicBreak};
15
16// TODO: maybe get rid of Copy/Clone here?
17// it's required by fold_many0
18#[derive(Debug, PartialEq, Eq, Copy, Clone)]
19pub enum MdxAst<'a> {
20    ATXHeading(ATXHeading<'a>),
21    ThematicBreak(ThematicBreak),
22    Paragraph(Paragraph<'a>),
23}
24impl<'a> fmt::Display for MdxAst<'a> {
25    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
26        match self {
27            MdxAst::ATXHeading(atx) => write!(f, "{}", atx),
28            MdxAst::ThematicBreak(brk) => write!(f, "{}", brk),
29            MdxAst::Paragraph(para) => write!(f, "{}", para),
30        }
31        // Use `self.number` to refer to each positional data point.
32    }
33}
34
35pub fn mdx_elements(input: &str) -> Result<Vec<MdxAst>, ErrorTree<Location>> {
36    final_parser(mdx_elements_internal)(input)
37}
38fn mdx_elements_internal(input: &str) -> IResult<&str, Vec<MdxAst>, ErrorTree<&str>> {
39    let (input, _) = multispace0(input)?;
40    let (input, result) = nom::multi::separated_list1(many1_count(newline), mdx_ast)(input)?;
41    let (input, _) = multispace0(input)?;
42    let (input, _) = nom::combinator::eof(input)?;
43    Ok((input, result))
44}
45
46fn mdx_ast(input: &str) -> IResult<&str, MdxAst, ErrorTree<&str>> {
47    nom::branch::alt((ast_atx_heading, ast_thematic_break, ast_paragraph))(input)
48}
49
50/// We have to wrap the structs to fit in the MdxAst
51fn ast_atx_heading(input: &str) -> IResult<&str, MdxAst, ErrorTree<&str>> {
52    let (input, atx) = atx_heading(input)?;
53    Ok((input, MdxAst::ATXHeading(atx)))
54}
55
56fn ast_thematic_break(input: &str) -> IResult<&str, MdxAst, ErrorTree<&str>> {
57    let (input, thematic_break) = thematic_break(input)?;
58    Ok((input, MdxAst::ThematicBreak(thematic_break)))
59}
60
61fn ast_paragraph(input: &str) -> IResult<&str, MdxAst, ErrorTree<&str>> {
62    let (input, paragraph) = paragraph(input)?;
63    Ok((input, MdxAst::Paragraph(paragraph)))
64}
65
66#[cfg(test)]
67mod tests {
68    use super::*;
69
70    #[test]
71    fn parse_heading() {
72        assert_eq!(
73            mdx_ast("# boop").unwrap(),
74            (
75                "",
76                MdxAst::ATXHeading(ATXHeading {
77                    level: 1,
78                    value: "boop"
79                }),
80            )
81        );
82    }
83    #[test]
84    fn parse_thematic_break() {
85        assert_eq!(
86            mdx_ast("---").unwrap(),
87            (
88                "",
89                MdxAst::ThematicBreak(ThematicBreak {
90                    char_count: 3,
91                    break_char: '-'
92                }),
93            )
94        );
95    }
96}
97
98#[cfg(test)]
99mod tests_2 {
100    use super::*;
101
102    #[test]
103    // this input string is sloppy for a reason.
104    // that reason is to ensure the parser handles sloppy
105    // input when it comes to whitespace
106    fn parse_headings() {
107        assert_eq!(
108            mdx_elements(
109                "
110# boop
111
112
113## boop
114
115"
116            )
117            .unwrap(),
118            vec![
119                MdxAst::ATXHeading(ATXHeading {
120                    level: 1,
121                    value: "boop"
122                }),
123                MdxAst::ATXHeading(ATXHeading {
124                    level: 2,
125                    value: "boop"
126                }),
127            ]
128        );
129    }
130}
mdx/ast.rs

mdx/
ast.rs
