orgize/src/elements/rule.rs
2020-05-06 10:51:10 +08:00

63 lines
2.1 KiB
Rust

use nom::{
bytes::complete::take_while_m_n, character::complete::space0, error::ParseError, IResult,
};
use crate::parse::combinators::{blank_lines_count, eol};
#[derive(Debug, Default, Clone)]
#[cfg_attr(test, derive(PartialEq))]
#[cfg_attr(feature = "ser", derive(serde::Serialize))]
pub struct Rule {
/// Numbers of blank lines between rule line and next non-blank line or
/// buffer's end
pub post_blank: usize,
}
impl Rule {
pub(crate) fn parse(input: &str) -> Option<(&str, Rule)> {
parse_rule::<()>(input).ok()
}
}
fn parse_rule<'a, E>(input: &'a str) -> IResult<&str, Rule, E>
where
E: ParseError<&'a str>,
{
let (input, _) = space0(input)?;
let (input, _) = take_while_m_n(5, usize::max_value(), |c| c == '-')(input)?;
let (input, _) = eol(input)?;
let (input, post_blank) = blank_lines_count(input)?;
Ok((input, Rule { post_blank }))
}
#[test]
fn parse() {
use nom::error::VerboseError;
assert_eq!(
parse_rule::<VerboseError<&str>>("-----"),
Ok(("", Rule { post_blank: 0 }))
);
assert_eq!(
parse_rule::<VerboseError<&str>>("--------"),
Ok(("", Rule { post_blank: 0 }))
);
assert_eq!(
parse_rule::<VerboseError<&str>>("-----\n\n\n"),
Ok(("", Rule { post_blank: 2 }))
);
assert_eq!(
parse_rule::<VerboseError<&str>>("----- \n"),
Ok(("", Rule { post_blank: 0 }))
);
assert!(parse_rule::<VerboseError<&str>>("").is_err());
assert!(parse_rule::<VerboseError<&str>>("----").is_err());
assert!(parse_rule::<VerboseError<&str>>("----").is_err());
assert!(parse_rule::<VerboseError<&str>>("None----").is_err());
assert!(parse_rule::<VerboseError<&str>>("None ----").is_err());
assert!(parse_rule::<VerboseError<&str>>("None------").is_err());
assert!(parse_rule::<VerboseError<&str>>("----None----").is_err());
assert!(parse_rule::<VerboseError<&str>>("\t\t----").is_err());
assert!(parse_rule::<VerboseError<&str>>("------None").is_err());
assert!(parse_rule::<VerboseError<&str>>("----- None").is_err());
}