feature: add support for typecasting

src/autoqasm/converters/typecast.py

@@ -0,0 +1,65 @@
+# Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+
+
+"""Converters for integer casting nodes."""
+
+import ast
+
+import gast
+from malt.core import ag_ctx, converter
+from malt.pyct import templates
+
+
+class TypecastTransformer(converter.Base):
+    def visit_Call(self, node: ast.stmt) -> ast.stmt:
+        """Converts type casting operations to their AutoQASM counterpart.
+
+        Args:
+            node (ast.stmt): AST node to transform.
+
+        Returns:
+            ast.stmt: Transformed node.
+        """
+        typecasts_supported = ["int"]
+        node = self.generic_visit(node)
+
+        if (
+            hasattr(node, "func")
+            and hasattr(node.func, "id")
+            and node.func.id in typecasts_supported
+        ):
+            template = f"ag__.{node.func.id}_typecast(argument_)"
+            new_node = templates.replace(
+                template,
+                argument_=node.args,
+                original=node,
+            )
+            new_node = new_node[0].value
+        else:
+            new_node = node
+        return new_node
+
+
+def transform(node: ast.stmt, ctx: ag_ctx.ControlStatusCtx) -> ast.stmt:
+    """Transform int cast nodes.
+
+    Args:
+        node (ast.stmt): AST node to transform.
+        ctx (ag_ctx.ControlStatusCtx): Transformer context.
+
+    Returns:
+        ast.stmt: Transformed node.
+    """
+
+    return TypecastTransformer(ctx).visit(node)

src/autoqasm/operators/__init__.py

@@ -39,3 +39,4 @@
 from .logical import or_  # noqa: F401
 from .return_statements import return_output_from_main  # noqa: F401
 from .slices import GetItemOpts, get_item, set_item  # noqa: F401
+from .typecast import int_typecast  # noqa: F401

src/autoqasm/operators/typecast.py

@@ -0,0 +1,35 @@
+# Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+
+
+"""Operators for int cast statements."""
+
+from typing import Any
+
+from autoqasm import types as aq_types
+
+
+def int_typecast(argument_: Any, *args, **kwargs) -> aq_types.IntVar | int:
+    """Operator declares the `oq` variable, or sets variable's value if it's
+    already declared.
+
+    Args:
+        argument_ (Any): object to be converted into an int.
+
+    Returns:
+        IntVar | int : IntVar object if argument is QASM type, else int.
+    """
+    if aq_types.is_qasm_type(argument_):
+        return aq_types.IntVar(argument_)
+    else:
+        return int(argument_, *args, **kwargs)

src/autoqasm/transpiler/transpiler.py

@@ -48,7 +48,13 @@
 from malt.utils import ag_logging as logging
 
 from autoqasm import operators, program, types
-from autoqasm.converters import assignments, break_statements, comparisons, return_statements
+from autoqasm.converters import (
+    assignments,
+    break_statements,
+    comparisons,
+    return_statements,
+    typecast,
+)
 
 
 class PyToOqpy(transpiler.PyToPy):
@@ -128,6 +134,7 @@ def transform_ast(
         # canonicalization creates.
         node = continue_statements.transform(node, ctx)
         node = return_statements.transform(node, ctx)
+        node = typecast.transform(node, ctx)
         node = assignments.transform(node, ctx)
         node = lists.transform(node, ctx)
         node = slices.transform(node, ctx)

test/unit_tests/autoqasm/test_api.py

@@ -1266,3 +1266,39 @@ def test(int[32] a, int[32] b) {
 test(2, 3);
 test(4, 5);"""
     assert main.build().to_ir() == expected
+
+
+class TestTypecasting:
+    def test_int_typecasting_on_measure(self):
+        @aq.main(num_qubits=2)
+        def main():
+            test = int(measure([0, 1]))
+
+        expected_ir = """OPENQASM 3.0;
+qubit[2] __qubits__;
+bit[2] __bit_0__ = "00";
+__bit_0__[0] = measure __qubits__[0];
+__bit_0__[1] = measure __qubits__[1];
+int[32] test = __bit_0__;"""
+        assert main.build().to_ir() == expected_ir
+
+    def test_int_typecasting_on_string(self):
+        @aq.main(num_qubits=2)
+        def main():
+            test = int("101", 2)
+
+        expected_ir = """OPENQASM 3.0;
+qubit[2] __qubits__;"""
+        assert main.build().to_ir() == expected_ir
+
+    def test_nested_int_typecasting(self):
+        @aq.main(num_qubits=2)
+        def main():
+            test = 2 * int(measure([0, 1]))
+
+        expected_ir = """OPENQASM 3.0;
+qubit[2] __qubits__;
+bit[2] __bit_0__ = "00";
+__bit_0__[0] = measure __qubits__[0];
+__bit_0__[1] = measure __qubits__[1];"""
+        assert main.build().to_ir() == expected_ir