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use crate as rune;
use crate::alloc::clone::TryClone;
use crate::runtime::{ProtocolCaller, Value, VmResult};
use crate::Any;
/// The state of a generator.
///
/// ```
/// use rune::{Value, Vm};
/// use rune::runtime::{Generator, GeneratorState};
/// use std::sync::Arc;
///
/// let mut sources = rune::sources! {
/// entry => {
/// pub fn main() {
/// let n = yield 1;
/// let out = yield n + 1;
/// out
/// }
/// }
/// };
///
/// let unit = rune::prepare(&mut sources).build()?;
///
/// let mut vm = Vm::without_runtime(Arc::new(unit));
/// let mut execution = vm.execute(["main"], ())?;
///
/// // Initial resume doesn't take a value.
/// let first = match execution.resume().into_result()? {
/// GeneratorState::Yielded(first) => rune::from_value::<i64>(first)?,
/// GeneratorState::Complete(..) => panic!("generator completed"),
/// };
///
/// assert_eq!(first, 1);
///
/// // Additional resumes require a value.
/// let second = match execution.resume_with(rune::to_value(2i64)?).into_result()? {
/// GeneratorState::Yielded(second) => rune::from_value::<i64>(second)?,
/// GeneratorState::Complete(..) => panic!("generator completed"),
/// };
///
/// assert_eq!(second, 3);
///
/// let ret = match execution.resume_with(rune::to_value(42i64)?).into_result()? {
/// GeneratorState::Complete(ret) => rune::from_value::<i64>(ret)?,
/// GeneratorState::Yielded(..) => panic!("generator yielded"),
/// };
///
/// assert_eq!(ret, 42);
/// # Ok::<_, rune::support::Error>(())
/// ```
#[derive(Any, Debug, TryClone)]
#[rune(item = ::std::ops::generator)]
pub enum GeneratorState {
/// The generator yielded.
#[rune(constructor)]
Yielded(#[rune(get, set)] Value),
/// The generator completed.
#[rune(constructor)]
Complete(#[rune(get, set)] Value),
}
impl GeneratorState {
/// Test if the state is yielded.
pub fn is_yielded(&self) -> bool {
matches!(self, Self::Yielded(..))
}
/// Test if the state is complete.
pub fn is_complete(&self) -> bool {
matches!(self, Self::Complete(..))
}
pub(crate) fn partial_eq_with(
&self,
other: &Self,
caller: &mut dyn ProtocolCaller,
) -> VmResult<bool> {
match (self, other) {
(GeneratorState::Yielded(a), GeneratorState::Yielded(b)) => {
Value::partial_eq_with(a, b, caller)
}
(GeneratorState::Complete(a), GeneratorState::Complete(b)) => {
Value::partial_eq_with(a, b, caller)
}
_ => VmResult::Ok(false),
}
}
pub(crate) fn eq_with(&self, other: &Self, caller: &mut dyn ProtocolCaller) -> VmResult<bool> {
match (self, other) {
(GeneratorState::Yielded(a), GeneratorState::Yielded(b)) => {
Value::eq_with(a, b, caller)
}
(GeneratorState::Complete(a), GeneratorState::Complete(b)) => {
Value::eq_with(a, b, caller)
}
_ => VmResult::Ok(false),
}
}
}