feat(hydroflow_plus)!: separate singletons into their own types (hydr…

…o-project#1425)

hydroflow_plus/src/builder/mod.rs

@@ -12,6 +12,7 @@ use quote::quote;
 use runtime_support::FreeVariable;
 use stageleft::*;
 
+use crate::cycle::CycleCollection;
 use crate::ir::{HfPlusLeaf, HfPlusNode, HfPlusSource};
 use crate::location::{Cluster, Location, LocationId, Process};
 use crate::stream::{Bounded, NoTick, Tick, Unbounded};
@@ -277,50 +278,7 @@ impl<'a> FlowBuilder<'a> {
         )
     }
 
-    #[allow(clippy::type_complexity)]
-    pub fn cycle<T, W, L: Location>(
-        &self,
-        on: &L,
-    ) -> (HfCycle<'a, T, W, NoTick, L>, Stream<'a, T, W, NoTick, L>) {
-        let next_id = {
-            let on_id = match on.id() {
-                LocationId::Process(id) => id,
-                LocationId::Cluster(id) => id,
-            };
-
-            let mut cycle_ids = self.cycle_ids.borrow_mut();
-            let next_id_entry = cycle_ids.entry(on_id).or_default();
-
-            let id = *next_id_entry;
-            *next_id_entry += 1;
-            id
-        };
-
-        let ident = syn::Ident::new(&format!("cycle_{}", next_id), Span::call_site());
-
-        (
-            HfCycle {
-                ident: ident.clone(),
-                location_kind: on.id(),
-                ir_leaves: self.ir_leaves().clone(),
-                _phantom: PhantomData,
-            },
-            Stream::new(
-                on.id(),
-                self.ir_leaves().clone(),
-                HfPlusNode::Persist(Box::new(HfPlusNode::CycleSource {
-                    ident,
-                    location_kind: on.id(),
-                })),
-            ),
-        )
-    }
-
-    #[allow(clippy::type_complexity)]
-    pub fn tick_cycle<T, W, L: Location>(
-        &self,
-        on: &L,
-    ) -> (HfCycle<'a, T, W, Tick, L>, Stream<'a, T, W, Tick, L>) {
+    pub fn cycle<S: CycleCollection<'a>>(&self, on: &S::Location) -> (HfCycle<'a, S>, S) {
         let next_id = {
             let on_id = match on.id() {
                 LocationId::Process(id) => id,
@@ -340,18 +298,9 @@ impl<'a> FlowBuilder<'a> {
         (
             HfCycle {
                 ident: ident.clone(),
-                location_kind: on.id(),
-                ir_leaves: self.ir_leaves().clone(),
                 _phantom: PhantomData,
             },
-            Stream::new(
-                on.id(),
-                self.ir_leaves().clone(),
-                HfPlusNode::CycleSource {
-                    ident,
-                    location_kind: on.id(),
-                },
-            ),
+            S::create_source(ident, self.ir_leaves.clone(), on.id()),
         )
     }
 }

hydroflow_plus/src/cycle.rs

@@ -1,44 +1,28 @@
 use std::marker::PhantomData;
 
 use crate::builder::FlowLeaves;
-use crate::ir::{HfPlusLeaf, HfPlusNode};
 use crate::location::{Location, LocationId};
-use crate::stream::{NoTick, Tick};
-use crate::Stream;
+
+pub trait CycleCollection<'a> {
+    type Location: Location;
+
+    fn create_source(ident: syn::Ident, ir_leaves: FlowLeaves<'a>, l: LocationId) -> Self;
+
+    fn complete(self, ident: syn::Ident);
+}
 
 /// Represents a fixpoint cycle in the graph that will be fulfilled
 /// by a stream that is not yet known.
 ///
-/// See [`Stream`] for an explainer on the type parameters.
-pub struct HfCycle<'a, T, W, C, N: Location> {
+/// See [`crate::FlowBuilder`] for an explainer on the type parameters.
+pub struct HfCycle<'a, S: CycleCollection<'a>> {
     pub(crate) ident: syn::Ident,
-    pub(crate) location_kind: LocationId,
-    pub(crate) ir_leaves: FlowLeaves<'a>,
-    pub(crate) _phantom: PhantomData<(N, &'a mut &'a (), T, W, C)>,
-}
-
-impl<'a, T, W, N: Location> HfCycle<'a, T, W, Tick, N> {
-    pub fn complete(self, stream: Stream<'a, T, W, Tick, N>) {
-        let ident = self.ident;
-
-        self.ir_leaves.borrow_mut().as_mut().expect("Attempted to add a cycle to a flow that has already been finalized. No cycles can be added after the flow has been compiled.").push(HfPlusLeaf::CycleSink {
-            ident,
-            location_kind: self.location_kind,
-            input: Box::new(stream.ir_node.into_inner()),
-        });
-    }
+    pub(crate) _phantom: PhantomData<(&'a mut &'a (), S)>,
 }
 
-impl<'a, T, W, N: Location> HfCycle<'a, T, W, NoTick, N> {
-    pub fn complete(self, stream: Stream<'a, T, W, NoTick, N>) {
+impl<'a, S: CycleCollection<'a>> HfCycle<'a, S> {
+    pub fn complete(self, stream: S) {
         let ident = self.ident;
-
-        self.ir_leaves.borrow_mut().as_mut().expect("Attempted to add a cycle to a flow that has already been finalized. No cycles can be added after the flow has been compiled.").push(HfPlusLeaf::CycleSink {
-            ident,
-            location_kind: self.location_kind,
-            input: Box::new(HfPlusNode::Unpersist(
-                Box::new(stream.ir_node.into_inner())
-            )),
-        });
+        S::complete(stream, ident)
     }
 }

hydroflow_plus/src/lib.rs

@@ -19,7 +19,10 @@ pub mod runtime_support {
 }
 
 pub mod stream;
-pub use stream::Stream;
+pub use stream::{Bounded, NoTick, Stream, Tick, Unbounded};
+
+pub mod singleton;
+pub use singleton::{Optional, Singleton};
 
 pub mod location;
 pub use location::{Cluster, Process};