Type initialiser accepts sequences, stores internally as tuples. Add tests which try to break things.

src/runtime/python/tests/test_basic.py

@@ -219,9 +219,11 @@ def test_Type_getters():
     h0 = mkDepHypo("x", Type([], "N", []))
     e0 = ExprVar(0)
     type = Type([h0], "N", [e0])
-    assert type.hypos == [h0]
+    assert len(type.hypos) == 1
+    assert type.hypos[0] == h0
     assert type.cat == "N"
-    assert type.exprs == [e0]
+    assert len(type.exprs) == 1
+    assert type.exprs[0] == e0
     with pytest.raises(AttributeError):
         type.fake
 

src/runtime/python/tests/test_breaking.py

@@ -0,0 +1,35 @@
+import os
+import pytest
+from pgf import *
+
+@pytest.fixture(scope="module")
+def PGF():
+    return readPGF("../haskell/tests/basic.pgf")
+
+
+def test_init_Type_tuples():
+    hypos = [mkDepHypo("x", Type([], "N", []))]
+    exprs = [ExprVar(0)]
+    ty = Type(tuple(hypos), "P", tuple(exprs))
+    assert str(ty) == "(x : N) -> P x"
+
+def test_init_Type_lists():
+    hypos = [mkDepHypo("x", Type([], "N", []))]
+    exprs = [ExprVar(0)]
+    ty = Type(hypos, "P", exprs)
+    assert str(ty) == "(x : N) -> P x"
+
+def test_Type_modify_shallow():
+    hypos = [(BIND_TYPE_EXPLICIT, "x", Type([], "N", []))]
+    exprs = [ExprVar(0)]
+    ty = Type(hypos, "P", exprs)
+    hypos.append(None)
+    assert str(ty) == "(x : N) -> P x"
+
+def test_Type_modify_deep():
+    hypos = [(BIND_TYPE_EXPLICIT, "x", Type([], "N", []))]
+    exprs = [ExprVar(0)]
+    ty = Type(hypos, "P", exprs)
+    with pytest.raises(AttributeError):
+        hypos[0][2].exprs.append(None)
+        assert str(ty) == "(x : N) -> P x"