Add: Incomplete basis_search function

crates/accelerate/src/basis/basis_translator/basis_search.rs

@@ -0,0 +1,66 @@
+// This code is part of Qiskit.
+//
+// (C) Copyright IBM 2024
+//
+// This code is licensed under the Apache License, Version 2.0. You may
+// obtain a copy of this license in the LICENSE.txt file in the root directory
+// of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+//
+// Any modifications or derivative works of this code must retain this
+// copyright notice, and modified files need to carry a notice indicating
+// that they have been altered from the originals.
+
+use ahash::HashSet;
+use faer::utils::vec;
+use pyo3::prelude::*;
+use qiskit_circuit::equivalence::{CircuitRep, EquivalenceLibrary, Key, NodeData};
+use qiskit_circuit::operations::Param;
+use smallvec::SmallVec;
+
+use crate::basis::basis_translator::basis_search_visitor::BasisSearchVisitor;
+
+#[pyfunction]
+pub(crate) fn basis_search(py: Python) -> Vec<(String, u32, SmallVec<[Param; 3]>)> {
+    todo!()
+}
+
+pub(crate) fn _basis_search<'a>(
+    py: Python,
+    equiv_lib: &mut EquivalenceLibrary,
+    source_basis: HashSet<(String, u32)>,
+    target_basis: HashSet<Key>,
+) -> Vec<(&'a str, u32, &'a [Param], &'a CircuitRep)> {
+    // TODO: Logs
+    let source_basis: HashSet<Key> = source_basis
+        .iter()
+        .map(|(gate_name, gate_num_qubits)| Key {
+            name: gate_name.to_string(),
+            num_qubits: *gate_num_qubits,
+        })
+        .collect();
+
+    // If source_basis is empty, no work needs to be done.
+    if source_basis.is_empty() {
+        return vec![];
+    }
+
+    // This is only necessary since gates in target basis are currently reported by
+    // their names and we need to have in addition the number of qubits they act on.
+    let target_basis_keys: Vec<Key> = equiv_lib
+        .keys()
+        .cloned()
+        .filter(|key| target_basis.contains(key))
+        .collect();
+
+    let graph_ref = &equiv_lib.graph;
+    let vis = BasisSearchVisitor::new(&graph_ref, source_basis, target_basis);
+
+    let dummy = graph_ref.add_node(
+        NodeData {
+            equivs: vec![],
+            key: Key { name: "key".to_string(), num_qubits: 0 },
+        }
+    );
+    // TODO: Finish the function.
+    vec![]
+}