rune/runtime/
generator_state.rs

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1use crate as rune;
2use crate::alloc::clone::TryClone;
3use crate::runtime::{ProtocolCaller, Value, VmResult};
4use crate::Any;
5
6/// The state of a generator.
7///
8/// ```
9/// use rune::{Value, Vm};
10/// use rune::runtime::{Generator, GeneratorState};
11/// use std::sync::Arc;
12///
13/// let mut sources = rune::sources! {
14///     entry => {
15///         pub fn main() {
16///             let n = yield 1;
17///             let out = yield n + 1;
18///             out
19///         }
20///     }
21/// };
22///
23/// let unit = rune::prepare(&mut sources).build()?;
24///
25/// let mut vm = Vm::without_runtime(Arc::new(unit));
26/// let mut execution = vm.execute(["main"], ())?;
27///
28/// // Initial resume doesn't take a value.
29/// let first = match execution.resume().into_result()? {
30///     GeneratorState::Yielded(first) => rune::from_value::<i64>(first)?,
31///     GeneratorState::Complete(..) => panic!("generator completed"),
32/// };
33///
34/// assert_eq!(first, 1);
35///
36/// // Additional resumes require a value.
37/// let second = match execution.resume_with(rune::to_value(2i64)?).into_result()? {
38///     GeneratorState::Yielded(second) => rune::from_value::<i64>(second)?,
39///     GeneratorState::Complete(..) => panic!("generator completed"),
40/// };
41///
42/// assert_eq!(second, 3);
43///
44/// let ret = match execution.resume_with(rune::to_value(42i64)?).into_result()? {
45///     GeneratorState::Complete(ret) => rune::from_value::<i64>(ret)?,
46///     GeneratorState::Yielded(..) => panic!("generator yielded"),
47/// };
48///
49/// assert_eq!(ret, 42);
50/// # Ok::<_, rune::support::Error>(())
51/// ```
52#[derive(Any, Debug, TryClone)]
53#[rune(item = ::std::ops::generator)]
54pub enum GeneratorState {
55    /// The generator yielded.
56    #[rune(constructor)]
57    Yielded(#[rune(get, set)] Value),
58    /// The generator completed.
59    #[rune(constructor)]
60    Complete(#[rune(get, set)] Value),
61}
62
63impl GeneratorState {
64    /// Test if the state is yielded.
65    pub fn is_yielded(&self) -> bool {
66        matches!(self, Self::Yielded(..))
67    }
68
69    /// Test if the state is complete.
70    pub fn is_complete(&self) -> bool {
71        matches!(self, Self::Complete(..))
72    }
73
74    pub(crate) fn partial_eq_with(
75        &self,
76        other: &Self,
77        caller: &mut dyn ProtocolCaller,
78    ) -> VmResult<bool> {
79        match (self, other) {
80            (GeneratorState::Yielded(a), GeneratorState::Yielded(b)) => {
81                Value::partial_eq_with(a, b, caller)
82            }
83            (GeneratorState::Complete(a), GeneratorState::Complete(b)) => {
84                Value::partial_eq_with(a, b, caller)
85            }
86            _ => VmResult::Ok(false),
87        }
88    }
89
90    pub(crate) fn eq_with(&self, other: &Self, caller: &mut dyn ProtocolCaller) -> VmResult<bool> {
91        match (self, other) {
92            (GeneratorState::Yielded(a), GeneratorState::Yielded(b)) => {
93                Value::eq_with(a, b, caller)
94            }
95            (GeneratorState::Complete(a), GeneratorState::Complete(b)) => {
96                Value::eq_with(a, b, caller)
97            }
98            _ => VmResult::Ok(false),
99        }
100    }
101}
rune/runtime/generator_state.rs

rune/runtime/
generator_state.rs
