fix: method inference should resolve on tuple type (#356)

fix #321

Author: Roger-luo

src/kirin/dialects/func/typeinfer.py

@@ -1,4 +1,4 @@
-from typing import Iterable, cast
+from typing import Iterable
 
 from kirin import ir, types
 from kirin.interp import Frame, MethodTable, ReturnValue, impl
@@ -38,7 +38,7 @@ def return_(
     def call(self, interp: TypeInference, frame: Frame, stmt: Call):
         # give up on dynamic method calls
         mt = interp.maybe_const(stmt.callee, ir.Method)
-        if mt is None:
+        if mt is None:  # not a constant method
             return self._solve_method_type(interp, frame, stmt)
         return self._invoke_method(
             interp,
@@ -57,16 +57,14 @@ def _solve_method_type(self, interp: TypeInference, frame: Frame, stmt: Call):
 
         if len(mt_inferred.vars) != 2:
             return (types.Bottom,)
-
         args = mt_inferred.vars[0]
         result = mt_inferred.vars[1]
         if not args.is_subseteq(types.Tuple):
             return (types.Bottom,)
 
         resolve = TypeResolution()
-        args = cast(types.Generic, args)
-        for arg, value in zip(args.vars, frame.get_values(stmt.inputs)):
-            resolve.solve(arg, value)
+        # NOTE: we are not using [...] below to be compatible with 3.10
+        resolve.solve(args, types.Tuple.where(frame.get_values(stmt.inputs)))
         return (resolve.substitute(result),)
 
     @impl(Invoke)

test/analysis/dataflow/typeinfer/test_selfref_closure.py

@@ -0,0 +1,21 @@
+from kirin import types
+from kirin.prelude import structural_no_opt
+from kirin.analysis import TypeInference
+
+
+def test_self_ref_closure():
+
+    @structural_no_opt
+    def should_work(n_qubits: int):
+        def self_ref_source(i_layer):
+            stride = n_qubits // (2**i_layer)
+            if stride == 0:
+                return
+
+            self_ref_source(i_layer + 1)
+
+        return self_ref_source
+
+    infer = TypeInference(structural_no_opt)
+    _, ret = infer.run_analysis(should_work, (types.Int,))
+    assert ret.is_equal(types.MethodType[types.Tuple[types.Any], types.NoneType])