rune/parse/
parse.rs

1use crate::alloc::{Box, Vec};
2use crate::compile;
3use crate::parse::{Parser, Peek};
4
5/// Helper derive to implement [`Parse`].
6pub use rune_macros::Parse;
7
8/// The parse trait, implemented by items that can be parsed.
9pub trait Parse
10where
11    Self: Sized,
12{
13    /// Parse the current item from the parser.
14    fn parse(p: &mut Parser<'_>) -> compile::Result<Self>;
15}
16
17impl<A, B> Parse for (A, B)
18where
19    A: Parse + Peek,
20    B: Parse,
21{
22    #[inline]
23    fn parse(parser: &mut Parser<'_>) -> compile::Result<Self> {
24        Ok((parser.parse()?, parser.parse()?))
25    }
26}
27
28/// Parse implementation for something that can be optionally parsed.
29impl<T> Parse for Option<T>
30where
31    T: Parse + Peek,
32{
33    #[inline]
34    fn parse(parser: &mut Parser<'_>) -> compile::Result<Self> {
35        Ok(if parser.peek::<T>()? {
36            Some(parser.parse()?)
37        } else {
38            None
39        })
40    }
41}
42
43/// Parse implementation for something that is boxed.
44impl<T> Parse for Box<T>
45where
46    T: Parse,
47{
48    #[inline]
49    fn parse(parser: &mut Parser<'_>) -> compile::Result<Self> {
50        Ok(Box::try_new(parser.parse()?)?)
51    }
52}
53
54/// Parser implementation for a vector.
55impl<T> Parse for Vec<T>
56where
57    T: Parse + Peek,
58{
59    #[inline]
60    fn parse(parser: &mut Parser<'_>) -> compile::Result<Self> {
61        let mut output = Vec::new();
62
63        while parser.peek::<T>()? {
64            output.try_push(parser.parse()?)?;
65        }
66
67        Ok(output)
68    }
69}