YAML Front Matter (YFM) 解析器

yaml-front-matter 将有效的YAML字符串解析为实现了serde的struct特质。

考虑以下位于Markdown文件顶部的YAML内容

---
title: 'Parsing a Markdown file metadata into a struct'
description: 'This tutorial walks you through the practice of parsing markdown files for metadata'
tags: ['markdown', 'rust', 'files', 'parsing', 'metadata']
similar_posts:
  - 'Rendering markdown'
  - 'Using Rust to render markdown'
date: '2021-09-13T03:48:00'
favorite_numbers:
    - 3.14
    - 1970
    - 12345
---

此crate负责从Markdown文件中提取此标题，并使用serde和serde_yaml解析提取的数据。

示例

use serde::Deserialize;
use yaml_front_matter::YamlFrontMatter;

const SIMPLE_MARKDOWN_YFM: &str = r#"
---
title: 'Parsing a Markdown file metadata into a struct'
description: 'This tutorial walks you through the practice of parsing markdown files for metadata'
tags: ['markdown', 'rust', 'files', 'parsing', 'metadata']
similar_posts:
  - 'Rendering markdown'
  - 'Using Rust to render markdown'
date: '2021-09-13T03:48:00'
favorite_numbers:
    - 3.14
    - 1970
    - 12345
---


# Parsing a **Markdown** file metadata into a `struct`

> This tutorial walks you through the practice of parsing markdown files for metadata
"#;

#[derive(Deserialize)]
struct Metadata {
    title: String,
    description: String,
    tags: Vec<String>,
    similar_posts: Vec<String>,
    date: String,
    favorite_numbers: Vec<f64>,
}

let result = YamlFrontMatter::parse::<Metadata>(&SIMPLE_MARKDOWN_YFM).unwrap();

let Metadata {
    title,
    description,
    tags,
    similar_posts,
    date,
    favorite_numbers,
} = result;

assert_eq!(title, "Parsing a Markdown file metadata into a struct");
assert_eq!(
    description,
    "This tutorial walks you through the practice of parsing markdown files for metadata"
);
assert_eq!(
    tags,
    vec!["markdown", "rust", "files", "parsing", "metadata"]
);
assert_eq!(
    similar_posts,
    vec!["Rendering markdown", "Using Rust to render markdown"]
);
assert_eq!(date, "2021-09-13T03:48:00");
assert_eq!(favorite_numbers, vec![3.14, 1970., 12345.]);