organic/src/parser/keyword_todo.rs
2023-09-14 02:24:06 -04:00

103 lines
3.6 KiB
Rust

use nom::branch::alt;
use nom::bytes::complete::tag;
use nom::bytes::complete::take_till;
use nom::character::complete::line_ending;
use nom::character::complete::space0;
use nom::character::complete::space1;
use nom::combinator::eof;
use nom::combinator::opt;
use nom::combinator::verify;
use nom::multi::separated_list0;
use nom::sequence::tuple;
use crate::error::Res;
// ref https://orgmode.org/manual/Per_002dfile-keywords.html
// ref https://orgmode.org/manual/Workflow-states.html
// Case is significant.
/// Parses the text in the value of a #+TODO keyword.
///
/// Example input: "foo bar baz | lorem ipsum"
pub(crate) fn todo_keywords<'s>(input: &'s str) -> Res<&'s str, (Vec<&'s str>, Vec<&'s str>)> {
let (remaining, mut before_pipe_words) = separated_list0(space1, todo_keyword_word)(input)?;
let (remaining, after_pipe_words) = opt(tuple((
tuple((space0, tag("|"), space0)),
separated_list0(space1, todo_keyword_word),
)))(remaining)?;
let (remaining, _eol) = alt((line_ending, eof))(remaining)?;
if let Some((_pipe, after_pipe_words)) = after_pipe_words {
Ok((remaining, (before_pipe_words, after_pipe_words)))
} else if !before_pipe_words.is_empty() {
// If there was no pipe, then the last word becomes a completion state instead.
let mut after_pipe_words = Vec::with_capacity(1);
after_pipe_words.push(
before_pipe_words
.pop()
.expect("If-statement proves this is Some."),
);
Ok((remaining, (before_pipe_words, after_pipe_words)))
} else {
// No words founds
Ok((remaining, (Vec::new(), Vec::new())))
}
}
fn todo_keyword_word<'s>(input: &'s str) -> Res<&'s str, &'s str> {
let (remaining, keyword) = verify(take_till(|c| "( \t\r\n|".contains(c)), |result: &str| {
!result.is_empty()
})(input)?;
let (remaining, _) = opt(tuple((
tag("("),
take_till(|c| "() \t\r\n|".contains(c)),
tag(")"),
)))(remaining)?;
Ok((remaining, keyword))
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn before_and_after() -> Result<(), Box<dyn std::error::Error>> {
let input = "foo bar baz | lorem ipsum";
let (remaining, (before_pipe_words, after_pipe_words)) = todo_keywords(input)?;
assert_eq!(remaining, "");
assert_eq!(before_pipe_words, vec!["foo", "bar", "baz"]);
assert_eq!(after_pipe_words, vec!["lorem", "ipsum"]);
Ok(())
}
#[test]
fn no_pipe() -> Result<(), Box<dyn std::error::Error>> {
let input = "foo bar baz";
let (remaining, (before_pipe_words, after_pipe_words)) = todo_keywords(input)?;
assert_eq!(remaining, "");
assert_eq!(before_pipe_words, vec!["foo", "bar"]);
assert_eq!(after_pipe_words, vec!["baz"]);
Ok(())
}
#[test]
fn early_pipe() -> Result<(), Box<dyn std::error::Error>> {
let input = "| foo bar baz";
let (remaining, (before_pipe_words, after_pipe_words)) = todo_keywords(input)?;
assert_eq!(remaining, "");
assert_eq!(before_pipe_words, Vec::<&str>::new());
assert_eq!(after_pipe_words, vec!["foo", "bar", "baz"]);
Ok(())
}
#[test]
fn late_pipe() -> Result<(), Box<dyn std::error::Error>> {
let input = "foo bar baz |";
let (remaining, (before_pipe_words, after_pipe_words)) = todo_keywords(input)?;
assert_eq!(remaining, "");
assert_eq!(before_pipe_words, vec!["foo", "bar", "baz"]);
assert_eq!(after_pipe_words, Vec::<&str>::new());
Ok(())
}
}