# A PDDL 3.1 parser, strongly typed
A parser for the Planning Domain Definition Language version 3.1: written in Rust, based on [nom](https://crates.io/crates/nom).
[](https://codecov.io/gh/sunsided/pddl-rs)
Crate documentation is available on [docs.rs/pddl](https://docs.rs/pddl).
```toml
[dependencies]
pddl = "*"
```
The domain/problem types can be used independently of the parser; the parser
is however enabled by default via the `parser` crate feature.
To disable the parser and its dependencies, use
```toml
[dependencies]
pddl = { version = "*", default-features = false }
```
Documentation comments are assembled from the PDDL papers and [nergmada/planning-wiki](https://github.com/nergmada/planning-wiki).
## Usage Example
See [`tests/briefcase_world.rs`](tests/briefcase_world.rs) for the full example.
### Parsing a Single Problem
```rust
use pddl::{Problem, Parser};
pub const BRIEFCASE_WORLD_PROBLEM: &'static str = r#"
(define (problem get-paid)
(:domain briefcase-world)
(:init (place home) (place office) ; place types
(object p) (object d) (object b) ; object types
(at B home) (at P home) (at D home) (in P)) ; setup
(:goal (and (at B office) (at D office) (at P home)))
)
"#;
fn main() {
let problem = Problem::from_str(BRIEFCASE_WORLD_PROBLEM).unwrap();
assert_eq!(problem.name(), "get-paid");
assert_eq!(problem.domain(), "briefcase-world");
assert!(problem.requirements().is_empty());
assert_eq!(problem.init().len(), 9);
assert_eq!(problem.goals().len(), 3);
}
```
### Parsing a File with Multiple Domains and Problems
PDDL files often contain multiple `(define ...)` blocks — domains and problems
in any order. Use `PddlFile` to parse them all at once:
```rust
use pddl::{PddlFile, Parser};
pub const PDDL_FILE: &'static str = r#"
(define (domain blocks-world)
(:requirements :strips)
(:predicates (clear ?x) (on ?x ?y) (on-table ?x))
; ... actions omitted for brevity
)
(define (problem blocks-problem-1)
(:domain blocks-world)
(:init (on-table a) (on b a) (clear b))
(:goal (and (on a b)))
)
(define (problem blocks-problem-2)
(:domain blocks-world)
(:init (on-table a) (on-table b) (clear a) (clear b))
(:goal (and (on b a)))
)
"#;
fn main() {
let file = PddlFile::from_str(PDDL_FILE).unwrap();
assert_eq!(file.domain_count(), 1);
assert_eq!(file.problem_count(), 2);
let domain = &file.domains[0];
assert_eq!(domain.name(), "blocks-world");
assert_eq!(domain.predicates().len(), 3);
let problem1 = &file.problems[0];
assert_eq!(problem1.name(), "blocks-problem-1");
assert_eq!(problem1.goals().len(), 1);
}
```
### Caveat Emptor
At this point the parser supports all domain and problem definition
elements required to fully describe a PDDL 3.1 environment.
However, since types and enum variants are named closely to the underlying
BNF descriptions (see below), they may be a bit unwieldy to use still.
### Supported Elements
Parsers were implemented based on the BNF elements listed in the paper:
> "Complete BNF description of PDDL 3.1 (completely corrected)",
> _Daniel L. Kovacs_
See [ELEMENTS.md](ELEMENTS.md) for a graph of BNF elements.