From 4fff8273384eb76473adef9892cdad7b090b869e Mon Sep 17 00:00:00 2001
From: Simon Forman <sforman@hushmail.com>
Date: Sat, 30 Jun 2018 23:20:00 -0700
Subject: [PATCH] Extra logging and another lil test.

---
 joy/utils/polytypes.py      | 16 ++++++++++++++++
 test/test_type_inference.py |  6 ++++++
 2 files changed, 22 insertions(+)

diff --git a/joy/utils/polytypes.py b/joy/utils/polytypes.py
index 1c4eb10..cd29265 100644
--- a/joy/utils/polytypes.py
+++ b/joy/utils/polytypes.py
@@ -153,6 +153,22 @@ class CombinatorJoyType(FunctionJoyType):
         return new_f[0][1]
 
 
+def _log_uni(U):
+  def inner(u, v, s=None):
+    _log.info(
+      '%3i %s U %s   w/ %s',
+      len(inspect_stack()), u, v, s,
+      )
+    res = U(u, v, s)
+    _log.info(
+      '%3i %s U %s   w/ %s => %s',
+      len(inspect_stack()), u, v, s, res,
+      )
+    return res
+  return inner
+
+
+@_log_uni
 def unify(u, v, s=None):
     '''
     Return a tuple of substitution dicts representing unifiers for u and v.
diff --git a/test/test_type_inference.py b/test/test_type_inference.py
index 17d25c3..2f10558 100644
--- a/test/test_type_inference.py
+++ b/test/test_type_inference.py
@@ -174,6 +174,12 @@ class TestYin(TestMixin, unittest.TestCase):
     # ([...1] -- [a2 ...1] [...3] a1)
     self.assertEqualTypeStructure(infer(*expression), [f])
 
+  def test_stack_dup_ccons(self):
+    expression = stack, dup, ccons
+    f = ((a1, s1), ((a1, ((a1, s1), (a1, s1))), s1))
+    # (... a1 -- ... [a1 [a1 ...] a1 ...])
+    self.assertEqualTypeStructure(infer(*expression), [f])
+
 ##  def test_(self):
 ##    expression = pop, swap, rolldown, rest, rest, cons, cons
 ##    f = 
-- 
2.11.0