From 3084751de01d961bff034df40caa2968be91d7c5 Mon Sep 17 00:00:00 2001
From: "Davide Gessa (dakk)" <gessadavide@gmail.com>
Date: Sat, 28 Oct 2023 15:27:35 +0200
Subject: [PATCH] multi-assign tuple unrolling

---
 qlasskit/ast2ast.py       | 22 ++++++++++++++++++++++
 test/test_qlassf_tuple.py | 15 +++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/qlasskit/ast2ast.py b/qlasskit/ast2ast.py
index c652f5b8..96eb6288 100644
--- a/qlasskit/ast2ast.py
+++ b/qlasskit/ast2ast.py
@@ -67,6 +67,28 @@ def visit_FunctionDef(self, node):
         return super().generic_visit(node)
 
     def visit_Assign(self, node):
+        # Transform multi-target assign to single target assigns
+        if len(node.targets) == 1 and hasattr(node.targets[0], "elts"):
+            _temptup = self.visit(
+                ast.Assign(targets=[ast.Name(id="_temptup")], value=node.value)
+            )
+
+            single_assigns = [
+                self.visit(
+                    ast.Assign(
+                        targets=[ast.Name(id=node.targets[0].elts[i].id)],
+                        value=ast.Subscript(
+                            value=ast.Name(id="_temptup"),
+                            slice=ast.Index(
+                                value=ast.Constant(value=i), ctx=ast.Load()
+                            ),
+                        ),
+                    )
+                )
+                for i in range(len(node.targets[0].elts))
+            ]
+            return [_temptup] + single_assigns
+
         was_known = node.targets[0].id in self.env
 
         if isinstance(node.value, ast.Name) and node.value.id in self.env:
diff --git a/test/test_qlassf_tuple.py b/test/test_qlassf_tuple.py
index e1209a73..79724813 100644
--- a/test/test_qlassf_tuple.py
+++ b/test/test_qlassf_tuple.py
@@ -123,6 +123,21 @@ def test_tuple_assign3(self):
         )
         compute_and_compare_results(self, qf)
 
+    def test_multi_assign(self):
+        f = "def test(a: bool) -> bool:\n\tc, d = a, not a\n\treturn c and d"
+        qf = qlassf(f, to_compile=COMPILATION_ENABLED)
+        compute_and_compare_results(self, qf)
+
+    def test_multi_assign2(self):
+        f = "def test() -> Qint4:\n\tc, d = 1, 2\n\treturn c+d"
+        qf = qlassf(f, to_compile=COMPILATION_ENABLED)
+        compute_and_compare_results(self, qf)
+
+    def test_multi_assign3(self):
+        f = "def test() -> Qint4:\n\tc, d, e = 1, 2, 0xa\n\treturn c+d+e"
+        qf = qlassf(f, to_compile=COMPILATION_ENABLED)
+        compute_and_compare_results(self, qf)
+
     def test_tuple_result(self):
         f = "def test(a: bool, b: bool) -> Tuple[bool,bool]:\n\treturn a,b"
         qf = qlassf(f, to_compile=COMPILATION_ENABLED)