effective 0.3.1

An effects library, an alternative to keyword generics
Documentation 
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use std::{pin::Pin, task::Context};

use crate::{Blocking, EffectResult, Effective, Failure, Fallible, Single};

/// Create an [`Effective`] that has a failure, a single value and no async
pub fn fallible<T>(t: T) -> FromFallible<T> {
    FromFallible { inner: Some(t) }
}

pin_project_lite::pin_project!(
    pub struct FromFallible<T> {
        pub inner: Option<T>,
    }
);

impl<T: Fallible> Effective for FromFallible<T> {
    type Item = T::Continue;
    type Failure = Failure<T::Break>;
    type Produces = Single;
    type Async = Blocking;

    fn poll_effect(
        self: Pin<&mut Self>,
        _: &mut Context<'_>,
    ) -> EffectResult<T::Continue, Failure<T::Break>, Single, Blocking> {
        let this = self.project();
        let x = this.inner.take().expect("polled after completion");
        match x.branch() {
            std::ops::ControlFlow::Continue(x) => EffectResult::Item(x),
            std::ops::ControlFlow::Break(x) => EffectResult::Failure(Failure(x)),
        }
    }
}