dvcompute 2.0.0

Discrete event simulation library (sequential simulation)
Documentation
// Copyright (c) 2020-2022  David Sorokin <davsor@mail.ru>, based in Yoshkar-Ola, Russia
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.

use crate::simulation::observable::*;

use dvcompute_utils::grc::Grc;

/// It represents the source of `Observable` computations.
#[must_use = "computations are lazy and do nothing unless to be run"]
#[derive(Clone)]
pub struct ObservableFn<T> where T: 'static {
    gen: Grc<Box<dyn Fn() -> ObservableBox<T>>>
}

impl<T> ObservableFn<T> {

    /// Create a new source of computations.
    #[inline]
    pub fn new<F, O>(f: F) -> Self
        where F: Fn() -> O + 'static,
              O: Observable<Message = T> + 'static
    {
        ObservableFn {
            gen: Grc::new(Box::new(move || { f().into_boxed() }))
        }
    }

    /// Get the next computation.
    #[inline]
    pub fn next(&self) -> ObservableBox<T> {
        (self.gen)()
    }
}