Convert python slice into AST node (#73)

* add slice to to_ast

* add test with oqpy variables

Author: jcjaskula-aws

oqpy/base.py

@@ -507,6 +507,12 @@ def to_ast(program: Program, item: AstConvertible) -> ast.Expression:
         if program.simplify_constants:
             return detect_and_convert_constants(item, program)
         return ast.FloatLiteral(item)
+    if isinstance(item, slice):
+        return ast.RangeDefinition(
+            to_ast(program, item.start) if item.start is not None else None,
+            to_ast(program, item.stop - 1) if item.stop is not None else None,
+            to_ast(program, item.step) if item.step is not None else None,
+        )
     if isinstance(item, Iterable):
         return ast.ArrayLiteral([to_ast(program, i) for i in item])
     if isinstance(item, ast.Expression):

tests/test_directives.py

@@ -2398,8 +2398,12 @@ def test_qubit_array():
     prog.gate([q[0], q[1]], "cnot")
     prog.gate([q[oqpy.Range(0, i)]], "cnot")
 
-    with pytest.raises(TypeError):
-        prog.gate([q[0:2]], "cnot")
+    prog.gate(q[0:2:1], "cnot")
+    prog.gate(q[0:2], "cnot")
+    prog.gate(q[0:], "cnot")
+    prog.gate(q[:2], "cnot")
+    prog.gate(q[:], "cnot")
+    prog.gate(q[i : i : IntVar(1, "j")], "cnot")
 
     s = oqpy.Qubit("s")
     with pytest.raises(TypeError):
@@ -2410,9 +2414,16 @@ def test_qubit_array():
         OPENQASM 3.0;
         qubit[2] q;
         int[32] i = 2;
+        int[32] j = 1;
         h q[0];
         cnot q[0], q[1];
         cnot q[0:i - 1];
+        cnot q[0:1:1];
+        cnot q[0:1];
+        cnot q[0:];
+        cnot q[:1];
+        cnot q[:];
+        cnot q[i:j:i - 1];
         """
     ).strip()