From 0a796a33906c72d9e735078835328cc950823d87 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Agust=C3=ADn=20Borgna?=
 <121866228+aborgna-q@users.noreply.github.com>
Date: Wed, 6 Sep 2023 12:01:02 +0200
Subject: [PATCH] feat: More general portgraph references (#494)

---
 Cargo.toml                  |  2 +-
 src/hugr/views.rs           | 10 ++++++----
 src/hugr/views/hierarchy.rs | 12 ++++++------
 src/hugr/views/sibling.rs   | 12 ++++++------
 4 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 708413edd..46d83d38b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,7 +24,7 @@ path = "src/lib.rs"
 
 [dependencies]
 thiserror = "1.0.28"
-portgraph = { version = "0.8.0", features = ["serde", "petgraph"] }
+portgraph = { version = "0.9.0", features = ["serde", "petgraph"] }
 pyo3 = { version = "0.19.0", optional = true, features = [
     "multiple-pymethods",
 ] }
diff --git a/src/hugr/views.rs b/src/hugr/views.rs
index d882eca42..0db5d39d0 100644
--- a/src/hugr/views.rs
+++ b/src/hugr/views.rs
@@ -382,10 +382,12 @@ pub(crate) mod sealed {
     /// view.
     pub trait HugrInternals {
         /// The underlying portgraph view type.
-        type Portgraph: LinkView;
+        type Portgraph<'p>: LinkView + Clone + 'p
+        where
+            Self: 'p;
 
         /// Returns a reference to the underlying portgraph.
-        fn portgraph(&self) -> &Self::Portgraph;
+        fn portgraph(&self) -> Self::Portgraph<'_>;
 
         /// Returns the Hugr at the base of a chain of views.
         fn base_hugr(&self) -> &Hugr;
@@ -398,10 +400,10 @@ pub(crate) mod sealed {
     where
         T: AsRef<super::Hugr>,
     {
-        type Portgraph = MultiPortGraph;
+        type Portgraph<'p> = &'p MultiPortGraph where Self: 'p;
 
         #[inline]
-        fn portgraph(&self) -> &Self::Portgraph {
+        fn portgraph(&self) -> Self::Portgraph<'_> {
             &self.as_ref().graph
         }
 
diff --git a/src/hugr/views/hierarchy.rs b/src/hugr/views/hierarchy.rs
index ed42d48b0..76d67ecff 100644
--- a/src/hugr/views/hierarchy.rs
+++ b/src/hugr/views/hierarchy.rs
@@ -29,7 +29,7 @@ use crate::{hugr::NodeType, hugr::OpType, Direction, Hugr, Node, Port};
 
 use super::{sealed::HugrInternals, HugrView, NodeMetadata};
 
-type FlatRegionGraph<'g> = portgraph::view::FlatRegion<'g, MultiPortGraph>;
+type FlatRegionGraph<'g> = portgraph::view::FlatRegion<'g, &'g MultiPortGraph>;
 
 /// View of a HUGR sibling graph.
 ///
@@ -221,7 +221,7 @@ where
     }
 }
 
-type RegionGraph<'g> = portgraph::view::Region<'g, MultiPortGraph>;
+type RegionGraph<'g> = portgraph::view::Region<'g, &'g MultiPortGraph>;
 
 /// View of a HUGR descendants graph.
 ///
@@ -483,10 +483,10 @@ where
     Root: NodeHandle,
     Base: HugrInternals,
 {
-    type Portgraph = FlatRegionGraph<'g>;
+    type Portgraph<'p> = &'p FlatRegionGraph<'g> where Self: 'p;
 
     #[inline]
-    fn portgraph(&self) -> &Self::Portgraph {
+    fn portgraph(&self) -> Self::Portgraph<'_> {
         &self.graph
     }
 
@@ -506,10 +506,10 @@ where
     Root: NodeHandle,
     Base: HugrInternals,
 {
-    type Portgraph = RegionGraph<'g>;
+    type Portgraph<'p> = &'p RegionGraph<'g> where Self: 'p;
 
     #[inline]
-    fn portgraph(&self) -> &Self::Portgraph {
+    fn portgraph(&self) -> Self::Portgraph<'_> {
         &self.graph
     }
 
diff --git a/src/hugr/views/sibling.rs b/src/hugr/views/sibling.rs
index 002c55eba..c344be6b2 100644
--- a/src/hugr/views/sibling.rs
+++ b/src/hugr/views/sibling.rs
@@ -81,7 +81,7 @@ impl<'g, Base: HugrView> SiblingSubgraph<'g, Base> {
     /// subgraph is empty.
     pub fn try_from_dataflow_graph<Root>(dfg_graph: &'g Base) -> Result<Self, InvalidSubgraph>
     where
-        Base: HugrView<RootHandle = Root>,
+        Base: Clone + HugrView<RootHandle = Root>,
         Root: ContainerHandle<ChildrenHandle = DataflowOpID>,
     {
         let parent = dfg_graph.root();
@@ -147,7 +147,7 @@ impl<'g, Base: HugrView> SiblingSubgraph<'g, Base> {
         outgoing: OutgoingPorts,
     ) -> Result<Self, InvalidSubgraph>
     where
-        Base: HugrView,
+        Base: Clone + HugrView,
     {
         let mut checker = ConvexChecker::new(base);
         Self::try_from_boundary_ports_with_checker(base, incoming, outgoing, &mut checker)
@@ -168,14 +168,14 @@ impl<'g, Base: HugrView> SiblingSubgraph<'g, Base> {
         checker: &mut ConvexChecker<'g, Base>,
     ) -> Result<Self, InvalidSubgraph>
     where
-        Base: HugrView,
+        Base: Clone + HugrView,
     {
         let pg = base.portgraph();
         let to_pg = |(n, p): (Node, Port)| pg.port_index(n.index, p.offset).expect("invalid port");
 
         // Ordering of the edges here is preserved and becomes ordering of the signature.
         let subpg = Subgraph::new_subgraph(
-            pg,
+            pg.clone(),
             inputs
                 .iter()
                 .flatten()
@@ -377,8 +377,8 @@ impl<'g, Base: HugrView> SiblingSubgraph<'g, Base> {
 ///
 /// This can be used when constructing multiple sibling subgraphs to speed up
 /// convexity checking.
-pub struct ConvexChecker<'g, Base: HugrView>(
-    portgraph::algorithms::ConvexChecker<&'g Base::Portgraph>,
+pub struct ConvexChecker<'g, Base: 'g + HugrView>(
+    portgraph::algorithms::ConvexChecker<Base::Portgraph<'g>>,
 );
 
 impl<'g, Base: HugrView> ConvexChecker<'g, Base> {