diff --git a/hugr-core/src/hugr.rs b/hugr-core/src/hugr.rs
index 2e21a2358..ed0fcca0a 100644
--- a/hugr-core/src/hugr.rs
+++ b/hugr-core/src/hugr.rs
@@ -176,9 +176,7 @@ impl Hugr {
let mut graph = MultiPortGraph::with_capacity(nodes, ports);
let hierarchy = Hierarchy::new();
let mut op_types = UnmanagedDenseMap::with_capacity(nodes);
- let root = graph.add_node(0, 0);
- // TODO: These extensions should be open in principle, but lets wait
- // until extensions can be inferred for open sets until changing this
+ let root = graph.add_node(root_node.input_count(), root_node.output_count());
op_types[root] = root_node;
Self {
diff --git a/hugr-core/src/hugr/validate.rs b/hugr-core/src/hugr/validate.rs
index ce4ae43a2..faf3e51af 100644
--- a/hugr-core/src/hugr/validate.rs
+++ b/hugr-core/src/hugr/validate.rs
@@ -166,11 +166,25 @@ impl<'a, 'b> ValidationContext<'a, 'b> {
))?;
}
// The Hugr can have only one root node.
+
+ for dir in Direction::BOTH {
+ // Check that we have the correct amount of ports and edges.
+ let num_ports = self.hugr.graph.num_ports(node.pg_index(), dir);
+ if num_ports != op_type.port_count(dir) {
+ return Err(ValidationError::WrongNumberOfPorts {
+ node,
+ optype: op_type.clone(),
+ actual: num_ports,
+ expected: op_type.port_count(dir),
+ dir,
+ });
+ }
+ }
+
if node == self.hugr.root() {
- // The root node has no edges.
- if self.hugr.graph.num_outputs(node.pg_index())
- + self.hugr.graph.num_inputs(node.pg_index())
- != 0
+ // The root node cannot have connected edges
+ if self.hugr.all_linked_inputs(node).next().is_some()
+ || self.hugr.all_linked_outputs(node).next().is_some()
{
return Err(ValidationError::RootWithEdges { node });
}
@@ -190,20 +204,6 @@ impl<'a, 'b> ValidationContext<'a, 'b> {
allowed_children,
});
}
-
- for dir in Direction::BOTH {
- // Check that we have the correct amount of ports and edges.
- let num_ports = self.hugr.graph.num_ports(node.pg_index(), dir);
- if num_ports != op_type.port_count(dir) {
- return Err(ValidationError::WrongNumberOfPorts {
- node,
- optype: op_type.clone(),
- actual: num_ports,
- expected: op_type.port_count(dir),
- dir,
- });
- }
- }
}
// Thirdly that the node has correct children
@@ -602,10 +602,14 @@ impl<'a, 'b> ValidationContext<'a, 'b> {
}
// Check port connections.
- for dir in Direction::BOTH {
- for (i, port_index) in self.hugr.graph.ports(node.pg_index(), dir).enumerate() {
- let port = Port::new(dir, i);
- self.validate_port(node, port, port_index, op_type, var_decls)?;
+ //
+ // Root nodes are ignored, as they cannot have connected edges.
+ if node != self.hugr.root() {
+ for dir in Direction::BOTH {
+ for (i, port_index) in self.hugr.graph.ports(node.pg_index(), dir).enumerate() {
+ let port = Port::new(dir, i);
+ self.validate_port(node, port, port_index, op_type, var_decls)?;
+ }
}
}
diff --git a/hugr-core/src/hugr/views.rs b/hugr-core/src/hugr/views.rs
index 6a52f33f0..5779070fa 100644
--- a/hugr-core/src/hugr/views.rs
+++ b/hugr-core/src/hugr/views.rs
@@ -24,7 +24,7 @@ use itertools::{Itertools, MapInto};
use portgraph::render::{DotFormat, MermaidFormat};
use portgraph::{multiportgraph, LinkView, PortView};
-use super::internal::{HugrInternals, HugrMutInternals};
+use super::internal::HugrInternals;
use super::{
Hugr, HugrError, HugrMut, NodeMetadata, NodeMetadataMap, ValidationError, DEFAULT_OPTYPE,
};
@@ -509,7 +509,6 @@ pub trait ExtractHugr: HugrView + Sized {
let old_root = hugr.root();
let new_root = hugr.insert_from_view(old_root, &self).new_root;
hugr.set_root(new_root);
- hugr.set_num_ports(new_root, 0, 0);
hugr.remove_node(old_root);
hugr
}
diff --git a/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_cfg.snap b/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_cfg.snap
index e81a393d8..7f7d769be 100644
--- a/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_cfg.snap
+++ b/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_cfg.snap
@@ -3,7 +3,7 @@ source: hugr-core/src/hugr/views/tests.rs
expression: h.dot_string()
---
digraph {
-0 [shape=plain label=<>]
+0 [shape=plain label=<>]
1 [shape=plain label=<>]
2 [shape=plain label=<>]
2:out0 -> 6:in0 [style="dashed"]
@@ -44,4 +44,3 @@ hier8 [shape=plain label="8"]
hier9 [shape=plain label="9"]
hier10 [shape=plain label="10"]
}
-
diff --git a/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_dfg.snap b/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_dfg.snap
index a77760fe3..2acf952eb 100644
--- a/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_dfg.snap
+++ b/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_dfg.snap
@@ -1,9 +1,9 @@
---
-source: hugr-core/views/tests.rs
+source: hugr-core/src/hugr/views/tests.rs
expression: h.dot_string()
---
digraph {
-0 [shape=plain label=<>]
+0 [shape=plain label=<| 0: qubit | 1: qubit |
| (0) DFG |
| 0: qubit | 1: qubit |
>]
1 [shape=plain label=<| (1) Input |
| 0: qubit | 1: qubit |
>]
1:out0 -> 3:in0 [style=""]
1:out1 -> 3:in1 [style=""]
diff --git a/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_empty_dfg.snap b/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_empty_dfg.snap
index fe82c83fe..0bae7e511 100644
--- a/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_empty_dfg.snap
+++ b/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_empty_dfg.snap
@@ -3,7 +3,7 @@ source: hugr-core/src/hugr/views/tests.rs
expression: h.dot_string()
---
digraph {
-0 [shape=plain label=<>]
+0 [shape=plain label=<>]
1 [shape=plain label=<>]
1:out0 -> 2:in0 [style=""]
2 [shape=plain label=<>]