Treat LoadConstant as transparent only if Const encoded

acl-cqc · acl-cqc · commit 10340d72a4d3 · 2025-11-11T12:34:27.000Z
diff --git a/tket/src/serialize/pytket/encoder.rs b/tket/src/serialize/pytket/encoder.rs
@@ -885,19 +885,21 @@ impl<H: HugrView> PytketEncoderContext<H> {
                 }
             }
             OpType::LoadConstant(constant) => {
-                // If we are loading a supported type, emit a transparent node
-                // by reassigning the input values to the new outputs.
-                //
-                // Otherwise, if we're loading an unsupported type, this node
-                // should be part of an unsupported subgraph.
+                let cst = circ
+                    .hugr()
+                    .single_linked_output(node, constant.constant_port())
+                    .expect("LoadConstant must have a linked Const");
+                // Check if the Const was successfully encoded
                 if self
-                    .config()
-                    .type_to_pytket(constant.constant_type())
+                    .values
+                    .peek_wire_values(Wire::new(cst.0, cst.1))
                     .is_some()
                 {
                     self.emit_transparent_node(node, circ, |ps| ps.input_params.to_owned())?;
                     return Ok(EncodeStatus::Success);
                 }
+                // Otherwise (inc. if we're loading an unsupported type), this node
+                // should be part of an unsupported subgraph.
             }
             OpType::Const(op) => {
                 let config = Arc::clone(&self.config);

Original file line number	Diff line number	Diff line change
`@@ -885,19 +885,21 @@ impl<H: HugrView> PytketEncoderContext<H> {`
`885`	`885`	`}`
`886`	`886`	`}`
`887`	`887`	`OpType::LoadConstant(constant) => {`
`888`		`- // If we are loading a supported type, emit a transparent node`
`889`		`- // by reassigning the input values to the new outputs.`
`890`		`- //`
`891`		`- // Otherwise, if we're loading an unsupported type, this node`
`892`		`- // should be part of an unsupported subgraph.`
	`888`	`+ let cst = circ`
	`889`	`+ .hugr()`
	`890`	`+ .single_linked_output(node, constant.constant_port())`
	`891`	`+ .expect("LoadConstant must have a linked Const");`
	`892`	`+ // Check if the Const was successfully encoded`
`893`	`893`	`if self`
`894`		`- .config()`
`895`		`- .type_to_pytket(constant.constant_type())`
	`894`	`+ .values`
	`895`	`+ .peek_wire_values(Wire::new(cst.0, cst.1))`
`896`	`896`	`.is_some()`
`897`	`897`	`{`
`898`	`898`	`self.emit_transparent_node(node, circ, \|ps\| ps.input_params.to_owned())?;`
`899`	`899`	`return Ok(EncodeStatus::Success);`
`900`	`900`	`}`
	`901`	`+ // Otherwise (inc. if we're loading an unsupported type), this node`
	`902`	`+ // should be part of an unsupported subgraph.`
`901`	`903`	`}`
`902`	`904`	`OpType::Const(op) => {`
`903`	`905`	`let config = Arc::clone(&self.config);`