5 files changed, 97 insertions, 2 deletions
diff --git a/progs/tests/func/wrong_params.sy b/progs/tests/func/wrong_params.sy
index e49e89b..0082a3a 100644
--- a/progs/tests/func/wrong_params.sy
+++ b/progs/tests/func/wrong_params.sy
@@ -4,4 +4,4 @@ start :: fn {
     f
 }
 
-// errors: [ErrorKind::TypeMismatch(_, _), ErrorKind::TypeMismatch(Type::Void, Type::Int)]
+// errors: [ErrorKind::TypeMismatch(_, _), ErrorKind::TypeMismatch(Type::Int, Type::Void)]
diff --git a/progs/tests/nullable_types.sy b/progs/tests/nullable_types.sy
new file mode 100644
index 0000000..2088c53
--- /dev/null
+++ b/progs/tests/nullable_types.sy
@@ -0,0 +1,33 @@
+test001 :: fn -> int {
+    a : int? = nil
+    a = 2
+    ret a
+}
+
+test002 :: fn b:bool -> int? {
+    if b {
+        ret nil
+    } else {
+        ret 0
+    }
+}
+
+// TODO(ed): Introduce type type!
+test003 :: fn {
+    a := test002! false
+    a += 1
+    a <=> 1
+}
+
+
+start :: fn {
+    test001!
+    nil <=> test002! true
+    0 <=> test002! false
+    q : bool? = true
+    q <=> true
+    q = nil
+    q <=> nil
+    test003!
+}
+
diff --git a/progs/tests/tuple/sub.sy b/progs/tests/tuple/sub.sy
index e5d60f2..cca4f2c 100644
--- a/progs/tests/tuple/sub.sy
+++ b/progs/tests/tuple/sub.sy
@@ -1,3 +1,4 @@
 start :: fn {
-    (1, -2, 3, -4) - (4, 3, -2, -1) <=> (-3, 1, 1, -5)
+    print (1, -2, 3, -4) - (4, 3, -2, -1)
+    (1, -2, 3, -4) - (4, 3, -2, -1) <=> (-3, -5, 5, -3)
 }
diff --git a/progs/tests/union_types_simple.sy b/progs/tests/union_types_simple.sy
new file mode 100644
index 0000000..f6cf622
--- /dev/null
+++ b/progs/tests/union_types_simple.sy
@@ -0,0 +1,36 @@
+f :: fn a:bool -> int | str | void {
+    if a {
+        ret 1
+    } else {
+        ret
+    }
+}
+
+g :: fn a:bool -> int | (bool, bool) {
+    if a {
+        ret 1
+    } else {
+        ret (true, true)
+    }
+}
+
+h :: fn a:bool -> int | fn -> int {
+    if a {
+        f :: fn -> int { ret 1 }
+        ret f
+    } else {
+        ret 1
+    }
+}
+
+start :: fn {
+    1 <=> f! true
+    nil <=> f! false
+    (true, true) <=> g! false
+    1 <=> g! true
+    f(true) <=> g(true)
+
+    1 <=> h! false
+    q :: h! true
+    1 <=> q()
+}
diff --git a/progs/tests/union_types_simple_faulty.sy b/progs/tests/union_types_simple_faulty.sy
new file mode 100644
index 0000000..b742054
--- /dev/null
+++ b/progs/tests/union_types_simple_faulty.sy
@@ -0,0 +1,25 @@
+f :: fn a:bool -> int | void {
+    if a {
+        ret 1
+    } else {
+        ret "hello!"
+    }
+}
+
+g :: fn a:bool -> int | (bool, bool) {
+    if a {
+        ret 1
+    } else {
+        ret (true, 1.0)
+    }
+}
+
+start :: fn {
+    0 <=> f! true
+    0.0 <=> f! false
+    ("hello!", "there") <=> g! false
+    1 <=> g! true
+    f(true) <=> g(true)
+}
+
+// errors: [ ErrorKind::TypeMismatch(_, _), ErrorKind::TypeMismatch(_, _), ErrorKind::TypeError(_, _), ErrorKind::TypeError(_, _) ]