pddl 0.1.0

A PDDL 3.1 parser, strongly typed
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72

//! Provides parsers for atomic formulae.

use crate::parsers::{parens, space_separated_list0, ws};
use crate::parsers::{parse_predicate, ParseResult, Span};
use crate::types::AtomicFormula;
use nom::branch::alt;
use nom::bytes::complete::tag;
use nom::character::complete::char;
use nom::combinator::map;
use nom::sequence::{delimited, tuple};

/// Parses an atomic formula, i.e. `(<predicate> t*) | (= t t)`.
///
/// ## Example
/// ```
/// # use nom::character::complete::alpha1;
/// # use pddl::parsers::{atomic_formula, Span, parse_name, UnwrapValue};
/// # use pddl::{AtomicFormula, EqualityAtomicFormula, PredicateAtomicFormula, Predicate};
/// assert!(atomic_formula(parse_name)(Span::new("(= x y)")).is_value(
///     AtomicFormula::Equality(EqualityAtomicFormula::new("x".into(), "y".into()))
/// ));
/// assert!(atomic_formula(parse_name)(Span::new("(move a b)")).is_value(
///     AtomicFormula::Predicate(PredicateAtomicFormula::new(Predicate::from("move"), vec!["a".into(), "b".into()]))
/// ));
/// ```
pub fn atomic_formula<'a, F, O>(
    inner: F,
) -> impl FnMut(Span<'a>) -> ParseResult<'a, AtomicFormula<O>>
where
    F: Clone + FnMut(Span<'a>) -> ParseResult<'a, O>,
{
    let equality = map(
        delimited(
            ws(tag("(=")),
            tuple((ws(inner.clone()), ws(inner.clone()))),
            ws(char(')')),
        ),
        |tuple| AtomicFormula::Equality(tuple.into()),
    );

    let predicate = map(
        parens(tuple((parse_predicate, ws(space_separated_list0(inner))))),
        |tuple| AtomicFormula::Predicate(tuple.into()),
    );

    alt((equality, predicate))
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::parsers::{parse_name, parse_term, UnwrapValue};
    use crate::{EqualityAtomicFormula, Predicate, PredicateAtomicFormula};

    #[test]
    fn it_works() {
        let input = "(can-move ?from-waypoint ?to-waypoint)";
        let (_, _effect) = atomic_formula(parse_term)(Span::new(input)).unwrap();
    }

    #[test]
    fn test_parse() {
        assert!(atomic_formula(parse_name)(Span::new("(= x y)")).is_value(
            AtomicFormula::Equality(EqualityAtomicFormula::new("x".into(), "y".into()))
        ));
        assert!(
            atomic_formula(parse_name)(Span::new("(move a b)")).is_value(AtomicFormula::Predicate(
                PredicateAtomicFormula::new(Predicate::from("move"), vec!["a".into(), "b".into()])
            ))
        );
    }
}