xesite/src/post/frontmatter.rs

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Rewrite site backend in Rust (#178) * add shell.nix changes for Rust #176 * set up base crate layout * add first set of dependencies * start adding basic app modules * start html templates * serve index page * add contact and feeds pages * add resume rendering support * resume cleanups * get signalboost page working * rewrite config to be in dhall * more work * basic generic post loading * more tests * initial blog index support * fix routing? * render blogposts * X-Clacks-Overhead * split blog handlers into blog.rs * gallery index * gallery posts * fix hashtags * remove instantpage (it messes up the metrics) * talk support + prometheus * Create rust.yml * Update rust.yml * Update codeql-analysis.yml * add jsonfeed library * jsonfeed support * rss/atom * go mod tidy * atom: add posted date * rss: add publishing date * nix: build rust program * rip out go code * rip out go templates * prepare for serving in docker * create kubernetes deployment * create automagic deployment * build docker images on non-master * more fixes * fix timestamps * fix RSS/Atom/JSONFeed validation errors * add go vanity import redirecting * templates/header: remove this * atom feed: fixes * fix? * fix?? * fix rust tests * Update rust.yml * automatically show snow during the winter * fix dates * show commit link in footer * sitemap support * fix compiler warning * start basic patreon client * integrate kankyo * fix patreon client * add patrons page * remove this * handle patron errors better * fix build * clean up deploy * sort envvars for deploy * remove deps.nix * shell.nix: remove go * update README * fix envvars for tests * nice * blog: add rewrite in rust post * blog/site-update: more words
2020-07-16 19:32:30 +00:00
/// This code was borrowed from @fasterthanlime.
use color_eyre::eyre::{Result};
Rewrite site backend in Rust (#178) * add shell.nix changes for Rust #176 * set up base crate layout * add first set of dependencies * start adding basic app modules * start html templates * serve index page * add contact and feeds pages * add resume rendering support * resume cleanups * get signalboost page working * rewrite config to be in dhall * more work * basic generic post loading * more tests * initial blog index support * fix routing? * render blogposts * X-Clacks-Overhead * split blog handlers into blog.rs * gallery index * gallery posts * fix hashtags * remove instantpage (it messes up the metrics) * talk support + prometheus * Create rust.yml * Update rust.yml * Update codeql-analysis.yml * add jsonfeed library * jsonfeed support * rss/atom * go mod tidy * atom: add posted date * rss: add publishing date * nix: build rust program * rip out go code * rip out go templates * prepare for serving in docker * create kubernetes deployment * create automagic deployment * build docker images on non-master * more fixes * fix timestamps * fix RSS/Atom/JSONFeed validation errors * add go vanity import redirecting * templates/header: remove this * atom feed: fixes * fix? * fix?? * fix rust tests * Update rust.yml * automatically show snow during the winter * fix dates * show commit link in footer * sitemap support * fix compiler warning * start basic patreon client * integrate kankyo * fix patreon client * add patrons page * remove this * handle patron errors better * fix build * clean up deploy * sort envvars for deploy * remove deps.nix * shell.nix: remove go * update README * fix envvars for tests * nice * blog: add rewrite in rust post * blog/site-update: more words
2020-07-16 19:32:30 +00:00
use serde::{Serialize, Deserialize};
#[derive(Eq, PartialEq, Deserialize, Default, Debug, Serialize, Clone)]
pub struct Data {
pub title: String,
pub date: String,
pub series: Option<String>,
pub tags: Option<Vec<String>>,
pub slides_link: Option<String>,
pub image: Option<String>,
pub thumb: Option<String>,
pub show: Option<bool>,
}
enum State {
SearchForStart,
ReadingMarker { count: usize, end: bool },
ReadingFrontMatter { buf: String, line_start: bool },
SkipNewline { end: bool },
}
#[derive(Debug, thiserror::Error)]
enum Error {
#[error("EOF while parsing frontmatter")]
EOF,
#[error("Error parsing yaml: {0:?}")]
Yaml(#[from] serde_yaml::Error),
}
impl Data {
pub fn parse(input: &str) -> Result<(Data, usize)> {
let mut state = State::SearchForStart;
let mut payload = None;
let offset;
let mut chars = input.char_indices();
'parse: loop {
let (idx, ch) = match chars.next() {
Some(x) => x,
None => return Err(Error::EOF)?,
};
match &mut state {
State::SearchForStart => match ch {
'-' => {
state = State::ReadingMarker {
count: 1,
end: false,
};
}
'\n' | '\t' | ' ' => {
// ignore whitespace
}
_ => {
panic!("Start of frontmatter not found");
}
},
State::ReadingMarker { count, end } => match ch {
'-' => {
*count += 1;
if *count == 3 {
state = State::SkipNewline { end: *end };
}
}
_ => {
panic!("Malformed frontmatter marker");
}
},
State::SkipNewline { end } => match ch {
'\n' => {
if *end {
offset = idx + 1;
break 'parse;
} else {
state = State::ReadingFrontMatter {
buf: String::new(),
line_start: true,
};
}
}
_ => panic!("Expected newline, got {:?}",),
},
State::ReadingFrontMatter { buf, line_start } => match ch {
'-' if *line_start => {
let mut state_temp = State::ReadingMarker {
count: 1,
end: true,
};
std::mem::swap(&mut state, &mut state_temp);
if let State::ReadingFrontMatter { buf, .. } = state_temp {
payload = Some(buf);
} else {
unreachable!();
}
}
ch => {
buf.push(ch);
*line_start = ch == '\n';
}
},
}
}
// unwrap justification: option set in state machine, Rust can't statically analyze it
let payload = payload.unwrap();
let fm: Self = serde_yaml::from_str(&payload)?;
Ok((fm, offset))
}
}