feat!: Cleanup core trait definitions (#2126)

Moves some methods around in `HugrInternals` / `HugrView` that we'll
require for #1926 and #2029. Notable changes:

- Adds a `hierarchy` method to `HugrInternals` that replaces most calls
to `base_hugr`.
- `HugrInternals::base_hugr` is now deprecated. It's only used by
`Sibling/DescendantGraph`, `validate` and a random use in
`DeadCodeElimPass`.
- Adds a `HugrInternals::region_portgraph` method that returns a
`FlatRegion` portgraph wrapper, and a `HugrView::descendants` call.
These lets us replace most uses of `SiblingGraph` and `DescendantGraph`.
- Renamed `HugrInternals::{get_pg_index,get_node}` to
`to_portgraph_node` and `from_portgraph_node`.

This requires some new changes in `portgraph`. I'll make a minor release
and update it here before merging.

We should be able to remove `base_hugr` after #2029. The deprecation
warning here is only temporary.

BREAKING CHANGE: Modified multiple core `HugrView` and `HugrInternals`
trait methods. See #2126.

Author: aborgna-q

Cargo.lock

@@ -58,7 +58,7 @@ regex = "1.10.6"
 regex-syntax = "0.8.3"
 rstest = "0.24.0"
 semver = "1.0.26"
-serde = "1.0.195"
+serde = "1.0.219"
 serde_json = "1.0.140"
 serde_yaml = "0.9.34"
 smol_str = "0.3.1"
@@ -87,8 +87,8 @@ zstd = "0.13.2"
 # These public dependencies usually require breaking changes downstream, so we
 # try to be as permissive as possible.
 pyo3 = ">= 0.23.4, < 0.25"
-portgraph = { version = ">= 0.13.3, < 0.15" }
-petgraph = { version = ">= 0.7.1, < 0.9", default-features = false }
+portgraph = { version = "0.14.1" }
+petgraph = { version = ">= 0.8.1, < 0.9", default-features = false }
 
 [profile.dev.package]
 insta.opt-level = 3

Cargo.toml

@@ -506,8 +506,8 @@ pub(crate) mod test {
 
     #[rstest]
     fn dfg_hugr(simple_dfg_hugr: Hugr) {
-        assert_eq!(simple_dfg_hugr.node_count(), 3);
-        assert_matches!(simple_dfg_hugr.root_type().tag(), OpTag::Dfg);
+        assert_eq!(simple_dfg_hugr.num_nodes(), 3);
+        assert_matches!(simple_dfg_hugr.root_optype().tag(), OpTag::Dfg);
     }
 
     #[test]
@@ -533,7 +533,7 @@ pub(crate) mod test {
         };
 
         let hugr = module_builder.finish_hugr()?;
-        assert_eq!(hugr.node_count(), 7);
+        assert_eq!(hugr.num_nodes(), 7);
 
         assert_eq!(hugr.get_metadata(hugr.root(), "x"), None);
         assert_eq!(hugr.get_metadata(dfg_node, "x").cloned(), Some(json!(42)));

hugr-core/src/builder/dataflow.rs

@@ -83,7 +83,7 @@ pub struct Wire<N = Node>(N, OutgoingPort);
 impl Node {
     /// Returns the node as a portgraph `NodeIndex`.
     #[inline]
-    pub(crate) fn pg_index(self) -> portgraph::NodeIndex {
+    pub(crate) fn into_portgraph(self) -> portgraph::NodeIndex {
         self.index
     }
 }

hugr-core/src/core.rs

@@ -1,4 +1,5 @@
 //! Exporting HUGR graphs to their `hugr-model` representation.
+use crate::hugr::internal::HugrInternals;
 use crate::{
     extension::{ExtensionId, OpDef, SignatureFunc},
     hugr::IdentList,
@@ -94,7 +95,7 @@ struct Context<'a> {
 impl<'a> Context<'a> {
     pub fn new(hugr: &'a Hugr, bump: &'a Bump) -> Self {
         let mut module = table::Module::default();
-        module.nodes.reserve(hugr.node_count());
+        module.nodes.reserve(hugr.num_nodes());
         let links = Links::new(hugr);
 
         Self {
@@ -999,7 +1000,7 @@ impl<'a> Context<'a> {
                 let outer_hugr = std::mem::replace(&mut self.hugr, hugr);
                 let outer_node_to_id = std::mem::take(&mut self.node_to_id);
 
-                let region = match hugr.root_type() {
+                let region = match hugr.root_optype() {
                     OpType::DFG(_) => self.export_dfg(hugr.root(), model::ScopeClosure::Closed),
                     _ => panic!("Value::Function root must be a DFG"),
                 };
@@ -1031,7 +1032,7 @@ impl<'a> Context<'a> {
     }
 
     pub fn export_node_metadata(&mut self, node: Node) -> &'a [table::TermId] {
-        let metadata_map = self.hugr.get_node_metadata(node);
+        let metadata_map = self.hugr.node_metadata_map(node);
 
         let has_order_edges = {
             fn is_relevant_node(hugr: &Hugr, node: Node) -> bool {
@@ -1049,13 +1050,11 @@ impl<'a> Context<'a> {
                 .any(|(other, _)| is_relevant_node(self.hugr, other))
         };
 
-        let meta_capacity = metadata_map.map_or(0, |map| map.len()) + has_order_edges as usize;
+        let meta_capacity = metadata_map.len() + has_order_edges as usize;
         let mut meta = BumpVec::with_capacity_in(meta_capacity, self.bump);
 
-        if let Some(metadata_map) = metadata_map {
-            for (name, value) in metadata_map {
-                meta.push(self.export_json_meta(name, value));
-            }
+        for (name, value) in metadata_map {
+            meta.push(self.export_json_meta(name, value));
         }
 
         if has_order_edges {